Trk Inhibition Reduces Tumorsphere Formation and Changes Expression of Stemness Markers in SK-ES-1 Ewing Sarcoma Cells / Inibição de Trk Reduz a Formação de Tumoresferas e Modifica a Expressão de Marcadores Tronco Tumorais em Células de Sarcoma de Ewing SK-ES-1 / Inhibición de Trk Reduce la Formación de Esferoides Tumorales y Cambia la Expresión de Marcadores de Stemness en Células de Sarcoma de Ewing SK-ES-1

Introduction: Ewing sarcoma (ES) is a highly aggressive type of childhood cancer characterized by a chromosomal translocation resulting in fusions between the gene encoding EWS RNA Binding Protein 1 (EWSR1) and one gene of the ETS family, most frequently FLI-1, resulting in the EWS-FLI1 aberrant transcription factor. ES tumors can contain a subpopulation of cells showing cancer stem cell (CSC) features, which express stemness markers including CD133, OCT4 (Octamer-binding transcription factor 4), and NANOG, and display capacity to form tumorspheres likely enriched in CSCs. Neurotrophin (NT) receptors of the tropomyosin receptor kinase (Trk) family (TrkA, TrkB, and TrkC) may play a role in stimulating ES progression, but their possible role in CSCs remains unknown. Objective: To verify the effect of Trks inhibition on the formation of tumorspheres as well as the gene expression of stem markers. Method: The cells were dissociated and the formation of spheres was induced with supplemented culture medium and the K252a treatment was performed. After RNA extraction, mRNA expression levels of target genes Prom1 (CD133), OCT4 (POU5F1), SOX2, and Musashi-1 (MSI1) were analyzed by qPCR. Results: The pan-Trk inhibitor K252a (100 or 500 mM) hindered tumorsphere formation in human SK-ES-1 ES cell cultures. K252a also reduced mRNA expression of Prom1 (CD133-coding gene) while enhancing expression of OCT4. No changes in mRNA levels of SOX2 or Musashi-1 were observed. Conclusion: These findings provide the first evidence suggesting that Trk activity can influence stemness in ES cells

Introdução: O sarcoma de Ewing (SE) é um tipo altamente agressivo de câncer infantil caracterizado por uma translocação cromossômica que resulta em fusões entre o gene que codifica a proteína de ligação a RNA EWS 1 (EWSR1) e um gene da família ETS, mais frequentemente o FLI-1, resultando no fator de transcrição aberrante EWS-FLI1. Os tumores de SE podem conter uma subpopulação de células com características de células-tronco tumorais (CTT), que expressam marcadores de pluripotência como CD133, OCT4 e NANOG, e têm a capacidade de formar esferas tumorais provavelmente enriquecidas em CTT. Os receptores de neurotrofinas (NT) da família de receptor de quinase de tropomiosina (Trk) (TrkA, TrkB e TrkC) podem desempenhar um papel no estímulo à progressão do SE, mas seu possível papel nas CTT permanece desconhecido. Objetivo: Verificar o efeito da inibição dos Trk na formação de tumoresferas, bem como na expressão gênica de marcadores de pluripotência. Método: As células foram dissociadas, a formação de esferas com meio de cultura suplementado foi induzida e realizou-se o tratamento com K252a. Após a extração de RNA, os níveis de expressão de mRNA dos genes-alvo Prom1 (CD133), OCT4 (POU5F1), SOX2 e Musashi-1 (MSI1) foram analisados por qPCR. Resultados: O inibidor pan-Trk K252a (100 ou 500 mM) impediu a formação de esferas tumorais em culturas de células de SE humanas SK-ES-1. O K252a também reduziu a expressão de mRNA de Prom1 (o gene que codifica CD133), enquanto aumentou a expressão de OCT4. Não foram observadas mudanças nos níveis de mRNA de SOX2 ou Musashi-1. Conclusão: Essas descobertas fornecem as primeiras evidências, sugerindo que a atividade dos Trk possa influenciar a pluripotência nas células de SE

Introducción: El sarcoma de Ewing (SE) es un tipo de cáncer infantil altamente agresivo caracterizado por una translocación cromosómica que resulta en fusiones entre el gen que codifica la proteína de unión a RNA EWS 1 (EWSR1) y un gen de la familia ETS, más frecuentemente FLI-1, lo que resulta en el factor de transcripción aberrante EWS-FLI1. Los tumores del SE pueden contener una subpoblación de células que presentan características de células madre cancerosas (CMC), las cuales expresan marcadores de pluripotencia como CD133, OCT4 y NANOG, y muestran la capacidad de formar esferas tumorales probablemente enriquecidas en CMC. Los receptores de neurotrofinas (NT) de la familia del receptor de quinasa de tropomiosina (Trk) (TrkA, TrkB y TrkC) podrían desempeñar un papel en el estímulo de la progresión del SE, pero su posible papel en las CMC aún es desconocido. Objetivo: Verificar el efecto de la inhibición de los Trk en la formación de esferoides tumorales, así como en la expresión génica de marcadores de pluripotencia. Método: Las células fueron disociadas e inducidas a formar esferas con un medio de cultivo suplementado y se realizó el tratamiento con K252a. Después de la extracción de ARN, los niveles de expresión de ARNm de los genes objetivo Prom1 (CD133), OCT4 (POU5F1), SOX2 y Musashi-1 (MSI1) se analizaron mediante qPCR. Resultados: El inhibidor pan-Trk K252a (100 o 500 mM) evitó la formación de esferas tumorales en cultivos de células de SE humanas SK-ES-1. El K252a también redujo la expresión de ARNm de Prom1 (el gen que codifica CD133), mientras que aumentaba la expresión de OCT4. No se observaron cambios en los niveles de ARNm de SOX2 o Musashi-1. Conclusión: Estos hallazgos proporcionan las primeras evidencias que sugieren que la actividad de Trk puede influir en la pluripotencia en las células del SE

Clinicopathological features of gastric carcinomas with NTRK-rearrangement/amplification: report of four cases / 中华病理学杂志

Objective: To investigate the clinicopathological, immunohistochemical and molecular genetic characteristics of gastric carcinoma with NTRK-rearrangement/amplification. Methods: The clinicopathological data of gastric carcinoma cases with NTRK-rearrangement/amplification diagnosed from January 2011 to September 2020 at the Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, China, were collected. The clinicopathological, immunophenotypic and molecular pathological features were analyzed. The relevant literature was reviewed. Results: There were 4 cases of gastric carcinoma with NTRK-rearrangement/amplification. All 4 patients were male, aged 57-67 years (average, 63 years). Tumor sizes ranged from 3.5 to 5.2 cm (average, 4.8 cm). All tumors were in the antrum. All 4 patients underwent radical gastrectomy and were followed up after the surgery. Morphologically, all tumors showed histological features with enteroblastic-differentiated gastric carcinoma. Tumor cells showed predominantly tubular/papillary architecture, with conspicuous vesicular nuclei and pale staining or transparent cytoplasm. Immunohistochemistry showed pan-TRK expression in all cases, with various degrees of positivity in the cytoplasm. All cases were subject to NTRK1/2/3 detection using fluorescence in situ hybridization. There were NTRK translocations in 2 cases and NTRK amplifications in 2 cases. These cases were further verified by RNAseq next generation sequencing which confirmed that NTRK1 gene translocation (TPM3-NTRK1) and NTRK2 gene translocation (NTRK2-SMCHD1) occurred in two cases, respectively. Conclusions: NTRK mutation occurs less frequently in gastric cancer. In this study, the cases mainly occur in the antrum. The morphology has the characteristics of enteroblastic differentiation. The tumors have unique histological, immunophenotypic and molecular characteristics, which require much attention from pathologists to effectively guide clinicians to choose the best treatment.

Effect of electroacupuncture at "Zusanli" (ST 36) on duodenal mast cells, NGF and NTRK1 in rats with functional dyspepsia / 中国针灸

OBJECTIVE@#To observe the effect of electroacupuncture (EA) at "Zusanli" (ST 36) on duodenal mast cells, nerve growth factor (NGF) and neurotrophic tyrosine kinase receptor type 1 (NTRK1), and to explore the mechanism of electroacupuncture at Zusanli (ST 36) on functional dyspepsia (FD).@*METHODS@#Sixty SPF-grade 10-day-old SD rats were randomly divided into a normal group, a model group, a ketotifen group and an EA group, 15 rats in each group. The FD model was prepared by iodoacetamide combined with rat tail clamping method in the model group, the ketotifen group and the EA group. The rats in the ketotifen group were injected intraperitoneally with ketotifen (1 mg•kg-1•d-1) for 7 days; the rats in the EA group were treated with EA at bilateral "Zusanli" (ST 36), with disperse-dense wave, frequency of 2 Hz/50 Hz and intensity of 0.5 mA, 20 min each time, once a day for 14 days. The gastric emptying rate and small intestinal propulsion rate in each group were observed; the morphology of duodenal mucosa was observed by HE staining; the toluidine blue staining was used to observe the number and degranulation of mast cells in duodenal mucosa; the protein and mRNA expressions of NGF, NTRK1 in duodenum were detected by Western blot and real-time PCR; the level of interleukin-1β (IL-1β) in duodenum was measured by ELISA.@*RESULTS@#Compared with the normal group, the gastric emptying rate and small intestinal propulsion rate in the model group were decreased (P<0.01); compared with the model group, the gastric emptying rate and small intestinal propulsion rate in the ketotifen group and the EA group were increased (P<0.01); the small intestinal propulsion rate in the EA group was higher than that in the ketotifen group (P<0.01). In the model group, local defects in duodenal mucosa were observed with a small amount of inflammatory cell infiltration; no obvious abnormality was found in duodenal mucosa of the other groups. Compared with the normal group, the mast cells of duodenal mucosa in the model group were increased significantly with significant degranulation; compared with the model group, the mast cells of duodenal mucosa in the ketotifen group and the EA group were decreased significantly, and the degranulation was not obvious. Compared with the normal group, the protein and mRNA expressions of NGF, NTRK1 as well as the level of IL-1β in duodenum in the model group were increased (P<0.01); compared with the model group, the protein and mRNA expressions of NGF, NTRK1 as well as the levels of IL-1β in duodenum in the ketotifen group and the EA group were decreased (P<0.01, P<0.05); compared with the ketotifen group, the mRNA expression of NGF, as well as the protein and mRNA expressions of NTRK1 in duodenum in the EA group were decreased (P<0.05, P<0.01).@*CONCLUSION@#EA at "Zusanli" (ST 36) could inhibit the activation of duodenal mast cells and regulate the expressions of NGF and its receptor to improve the low-grade inflammatory response of duodenum, resulting in treatment effect on FD.

Study of neurotrophic factor receptor tyrosine kinase gene fusion in the precise treatment of wild-type gastrointestinal stromal tumor / 中华胃肠外科杂志

The neurotrophin receptor kinase (NTRK) gene encodes neurotrophic factor receptor tyrosine kinase (NTRK), which plays an important role in the development and function of the nervous system. NTRK gene fusion mutation results in the production of chimeric NTRK proteins, which have carcinogenic potential through constitutive activation or overexpression. NTRK gene fusion mutation can lead to a special type of wild type gastrointestinal stromal tumor (GIST), whose clinical manifestations and treatment are completely different from other types of GIST. This fusion mutation can be detected clinically by a variety of methods, including tumor DNA and RNA sequencing and immunohistochemical staining. In patients with NTRK fusion positive tumors, NTRK inhibitors such as larotrectinib and entrectinib have shown good antitumor efficacy, with clinical response rates as high as 75%. Therefore, there is a need to improve the recognition and detection of fuch patients and to improve their prognosis by individualized and precise treatment with TRK inhibitors.

Congenital insensitivity to pain with anhidrosis: A case report and literature review / 中南大学学报(医学版)

To analyze the clinical manifestations and gene mutations in children with congenital insensitivity to pain with anhidrosis (CIPA), and review related literature. An infant diagnosed with congenital insensitivity to pain with anhidrosis was reported. The main clinical manifestations of the infant were painless, no sweat, and repeated fever. Peripheral blood of the infant and his parents was collected, and candidate variants were confirmed by Sanger sequencing. The results of molecular genetic analysis showed that there were compound heterozygous mutations (c.36G>A, c.851-33T>A) of neurotrophic tyrosine kinase receptor type 1 (NTRK1) in the infant. c.36G>A and c.851-33T>A were inherited from his father and mother, respectively. c.851-33T>A is a previously reported mutation, c.36G>A is an unreported mutation, which can lead to the tryptophan changing into a stop codon. According to the American College of Medical Genetics and Genomics (ACMG) variant interpretation guidelines, the mutation is interpreted as pathogenic, and the biological hazard is potentially harmful. Congenital insensitivity to pain with anhidrosis is a rare inherited disorder. Genetic molecular genetic analysis is helpful to diagnose and discover new gene mutations.

Mouse Nerve Growth Factor Facilitates the Growth of Interspinal Schwannoma Cells by Activating NGF Receptors

OBJECTIVE: Nerve growth factor (NGF) is a member of the neurotrophic factor family and plays a vital role in the physiological processes of organisms, especially in the nervous system. Many recent studies have reported that NGF is also involved in the regulation of tumourigenesis by either promoting or suppressing tumor growth, which depends on the location and type of tumor. However, little is known regarding the effect of NGF on interspinal schwannoma (IS). In the present study, we aimed to explored whether mouse nerve growth factor (mNGF), which is widely used in the clinic, can influence the growth of interspinal schwannoma cells (ISCs) isolated from IS in vitro. METHODS: ISCs were isolated, cultured and identified by S-100 with immunofluorescence analysis. S-100-positive cells were divided into five groups, and separately cultured with various concentrations of mNGF (0 [phosphate buffered saline, PBS], 40, 80, 160, and 320 ng/mL) for 24 hours. Western blot and quantantive real time polymerase chain reaction (PCR) were applied to detect tyrosine kinase A (TrkA) receptor and p75 neurotrophin receptor (p75(NTR)) in each group. Crystal violet staining was selected to assess the effect of mNGF (160 ng/mL) on ISCs growth. RESULTS: ISCs growth was enhanced by mNGF in a dose-dependent manner. The result of crystal violet staining revealed that it was significantly strengthened the cells growth kinetics when cultured with 160 ng/mL mNGF compared to PBS group. Western blot and quantantive real time PCR discovered that TrkA receptor and mRNA expression were both up-regualated under the condition of mNGF, expecially in 160 ng/mL, while the exoression of p75(NTR) demonstrated no difference among groups. CONCLUSION: From these data, we conclude that exogenous mNGF can facilitate ISC growth by activating both TrkA receptor and p75(NTR). In addition, patients who are suffering from IS should not be administered mNGF in the clinic.

Mouse Nerve Growth Factor Facilitates the Growth of Interspinal Schwannoma Cells by Activating NGF Receptors

OBJECTIVE: Nerve growth factor (NGF) is a member of the neurotrophic factor family and plays a vital role in the physiological processes of organisms, especially in the nervous system. Many recent studies have reported that NGF is also involved in the regulation of tumourigenesis by either promoting or suppressing tumor growth, which depends on the location and type of tumor. However, little is known regarding the effect of NGF on interspinal schwannoma (IS). In the present study, we aimed to explored whether mouse nerve growth factor (mNGF), which is widely used in the clinic, can influence the growth of interspinal schwannoma cells (ISCs) isolated from IS in vitro.METHODS: ISCs were isolated, cultured and identified by S-100 with immunofluorescence analysis. S-100-positive cells were divided into five groups, and separately cultured with various concentrations of mNGF (0 [phosphate buffered saline, PBS], 40, 80, 160, and 320 ng/mL) for 24 hours. Western blot and quantantive real time polymerase chain reaction (PCR) were applied to detect tyrosine kinase A (TrkA) receptor and p75 neurotrophin receptor (p75(NTR)) in each group. Crystal violet staining was selected to assess the effect of mNGF (160 ng/mL) on ISCs growth.RESULTS: ISCs growth was enhanced by mNGF in a dose-dependent manner. The result of crystal violet staining revealed that it was significantly strengthened the cells growth kinetics when cultured with 160 ng/mL mNGF compared to PBS group. Western blot and quantantive real time PCR discovered that TrkA receptor and mRNA expression were both up-regualated under the condition of mNGF, expecially in 160 ng/mL, while the exoression of p75(NTR) demonstrated no difference among groups.CONCLUSION: From these data, we conclude that exogenous mNGF can facilitate ISC growth by activating both TrkA receptor and p75(NTR). In addition, patients who are suffering from IS should not be administered mNGF in the clinic.

Expressão de neurotrofinas e de seus receptores no osteossarcoma primário / Expression of neurotrophins and their receptors in primary osteosarcoma

RESUMO Objetivo: determinar a expressão de neurotrofinas e seus receptores tirosina quinases em pacientes com osteossarcoma (OS) e sua correlação com desfechos clínicos. Métodos: biópsias de tumores primários de pacientes com OS tratados em uma única instituição, consecutivamente, entre 2002 e 2015, foram analisados através de imuno-histoquímica para expressão de receptores de tirosina quinase A e B (TrKA e TrKB), fator de crescimento neural (NGF) e fator neurotrófico derivado do cérebro (BDNF). De forma independente, dois patologistas classificaram os marcadores de imuno-histoquímica como negativos (negativos e focais fracos) ou positivos (moderado focal/difuso ou forte focal/difuso). Resultados: foram analisados dados de 19 pacientes (10 do sexo feminino e 9 do masculino) com mediana de idade de 12 anos (5 a 17,3 anos). Dos tumores, 83,3% estavam localizados em membros inferiores e 63,2% dos pacientes eram metastáticos ao diagnóstico. A sobrevida global em cinco anos foi de 55,3%. BDNF foi positivo em 16 pacientes (84%) e NGF em 14 pacientes (73%). TrKA e TrKB apresentaram coloração positiva em quatro (21,1%) e oito (42,1%) pacientes, respectivamente. A análise de sobrevida não demonstrou diferença significativa entre receptores TrK e neurotrofinas. Conclusão: amostras de OS primário expressam neurotrofinas e receptores TrK através de imuno-histoquímica. Estudos futuros podem auxiliar na identificação do papel das mesmas na patogênese do OS e determinar se há possível correlação prognóstica.

ABSTRACT Objective: to determine the expression of neurotrophins and their tyrosine-kinase receptors in patients with osteosarcoma (OS) and their correlation with clinical outcomes. Methods: we applied immunohistochemistry to biopsy specimens of patients consecutively treated for primary OS at a single institution between 2002 and 2015, analyzing them for expression receptors of tyrosine kinase A and B (TrKA and TrKB), neural growth factor (NGF) and brain derived neurotrophic factor (BDNF). Independently, two pathologists classified the immunohistochemical markers as negative (negative or weak focal) or positive (moderate focal/diffuse or strong focal/diffuse). Results: we analyzed data from 19 patients (10 females and 9 males), with median age of 12 years (5 to 17.3). Tumors' location were 83.3% in the lower limbs, and 63.2% of patients had metastases at diagnosis. Five-year overall survival was 55.3%. BDNF was positive in 16 patients (84%) and NGF in 14 (73%). TrKA and TrKB presented positive staining in four (21,1%) and eight (42,1%) patients, respectively. Survival analysis showed no significant difference between TrK receptors and neurotrophins. Conclusion: primary OS samples express neurotrophins and TrK receptors by immunohistochemistry. Future studies should explore their role in OS pathogenesis and determine their prognostic significance in larger cohorts.

Whole-tissue 3D imaging reveals intra-adipose sympathetic plasticity regulated by NGF-TrkA signal in cold-induced beiging

Sympathetic arborizations act as the essential efferent signals in regulating the metabolism of peripheral organs including white adipose tissues (WAT). However, whether these local neural structures would be of plastic nature, and how such plasticity might participate in specific metabolic events of WAT, remains largely uncharacterized. In this study, we exploit the new volume fluorescence-imaging technique to observe the significant, and also reversible, plasticity of intra-adipose sympathetic arborizations in mouse inguinal WAT in response to cold challenge. We demonstrate that this sympathetic plasticity depends on the cold-elicited signal of nerve growth factor (NGF) and TrkA receptor. Blockage of NGF or TrkA signaling suppresses intra-adipose sympathetic plasticity, and moreover, the cold-induced beiging process of WAT. Furthermore, we show that NGF expression in WAT depends on the catecholamine signal in cold challenge. We therefore reveal the key physiological relevance, together with the regulatory mechanism, of intra-adipose sympathetic plasticity in the WAT metabolism.

Mutation analysis of NTRK1 gene in a family affected with congenital insensitivity to pain with anhidrosis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To screen for mutations of NTRK1 gene in a Chinese family affected with congenital insensitivity to pain with anhidrosis (CIPA).</p><p><b>METHODS</b>Genomic DNA was extracted from the proband and her family members. All of the 17 exons and intron-exon boundaries of the NTRK1 gene were analyzed by direct Sanger sequencing. For the deletional mutation, the PCR products were subjected to T-A cloning and sequencing to verify the mutation.</p><p><b>RESULTS</b>NTRK1 gene analysis revealed that proband has carried a c.1786C>T (p.Arg596*) nonsense mutation inherited from her mother and a novel deletional mutation c.1928-2028+23del from her father. Her elder brother only carried the deletional mutation.</p><p><b>CONCLUSION</b>The diagnosis of CIPA relied on typical clinical symptoms of no pain, anhidrosis and intellectual disability and detection of the biallelic NTRK1 mutations. The novel deletional mutation has enriched the spectrum of NTRK1 mutations.</p>

Effect of bee venom injection on TrkA and TRPV1 expression in the dorsal root ganglion of rats with collagen-induced arthritis / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the therapeutic effect of acupoint injection of bee venom on collagen-induced arthritis (CIA) in rats and explore the mechanism of bee venom therapy in the treatment of rheumatoid arthritis.</p><p><b>METHODS</b>Fifteen male Wistar rats were randomly divided into bee venom treatment group (BV group), CIA model group, and control group. In the former two groups, CIA was induced by injections of collagen II+IFA (0.2 mL) via the tail vein, and in the control group, normal saline was injected instead. The rats in BV group received daily injection of 0.1 mL (3 mg/mL) bee venom for 7 consecutive days. All the rats were assessed for paw thickness and arthritis index from days 14 to 21, and the pain threshold was determined on day 21. The expressions of TRPV1 and TrkA in the dorsal root ganglion at the level of L4-6 were detected using immunohistochemistry and Western blotting, respectively.</p><p><b>RESULTS</b>The rats in CIA model group started to show paw swelling on day 10, and by day 14, all the rats in this group showed typical signs of CIA. In BV group, the rats receiving been venom therapy for 7 days showed a significantly smaller paw thickness and a low arthritis index than those in the model group. The pain threshold was the highest in the control group and the lowest in the model group. TRPV1-positive cells and TrkA expression in the dorsal root ganglion was significantly reduced in BV group as compared with that in the model group.</p><p><b>CONCLUSION</b>s Injection of bee venom can decrease expression of TRPV1 and TrkA in the dorsal root ganglion to produce anti-inflammatory and analgesic effects, suggesting the potential value of bee venom in the treatment of rheumatoid arthritis.</p>

Expression ratio of the nerve growth factor receptor TrkA to p75NTR correlates with the clinical stage and pathological grade of prostate cancer / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the expressions and action mechanisms of nerve growth factor (NGF) receptors TrkA and p75NTR in the oncogenesis and progression of prostate cancer (PCa).</p><p><b>METHODS</b>Using immunohistochemistry, we detected the expressions of TrkA and p75NTR in 62 PCa and 35 benign prostatic hyperplasia (BPH) samples, and conducted statistical analysis on the basis of clinical data.</p><p><b>RESULTS</b>Independent-samples t-test showed that, along with poorer tissue differentiation or higher clinical stage of PCa, the expression of TrkA was significantly up-regulated, that of p75NTR remarkably down-regulated, and the expression ratio of TrkA to p75NTR markedly increased. The TrkA/p75NTR ratio was 0.32 in the BPH, 0.52 in the PCa tissue with Gleason score of 6, 1.65 in the PCa tissue with Gleason score of 7, 5.75 in the PCa tissue with Gleason score ≥ 8, 0.89 in the clinical stage of pT2, 1.5 in pT3 a, 3.75 in pT3b, and 7.00 in pTxN1.</p><p><b>CONCLUSION</b>The abnormally increased expression ratio of TrkA to p75NTR might be one of the essential features of malignant transformation of prostate cells. A higher TrkA/p75NTR expression ratio may be associated with a lower tissue differentiation, a higher clinical stage or Gleason score, and therefore a poorer prognosis.</p>

Effect of Draconis Sanguis-containing serum on NGF, BDNF, CNTF, LNGFR, TrkA, GDNF, GAP-43 and NF-H expressions in Schwann cells / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect of Draconis Sanguis-containing serum on the expressions of NGF, BDNF, CNTF, LNG-FR, TrkA, GDNF, GAP-43 and NF-H in Schwann cells, and investigate the possible mechanism of Draconis Sanguis to promote peripheral nerve regeneration.</p><p><b>METHOD</b>SD rats were randomly divided into 2 groups: the Draconis Sanguis group (orally administered with Draconis Sanguis-containing balm solution) and the blank group (equivoluminal balm) to prepare Draconis Sanguis-containing serum and blank control serum. Schwann cells were extracted from double sciatic nerves of three-day-old SD rats, divided into 2 groups: the Draconis Sanguis group and the blank control group, and respectively cultured with 10% Draconis Sanguis-containing serum or blank control serum. The mRNA expressions of NGF, BDNF, CNTF and other genes in Schwann cells were measured by RT-PCR analysis 48 hours later.</p><p><b>RESULT</b>Most of the Schwann cells were bipolar spindle and arranged shoulder to shoulder or end to end under the microscope and identified to be positive with the immunocytochemical method. To compare with the blank group, mRNA expressions of NGF, LNGFR, GDNF and GAP-43 significantly increased (P < 0.01). Whereas that of BDNF decreased significantly (P < 0.05), and so did that of TrkA, CNTF (P < 0.01), with no remarkable difference in NF-H-mRNA.</p><p><b>CONCLUSION</b>Traditional Chinese medicine Draconis Sanguis may show effect in nerve regeneration by up-regulating mRNA expressions of NGF, LNGFR, GDNF and GAP-43 and down-regulating mRNA expressions of TrkA, BDNF and CNTF.</p>

A novel mutation of NTRK1 gene in a family with congenital insensitivity to pain with anhidrosis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To screen for mutations in the neurotrophic tyrosine kinase receptor type 1 (NTRK1) gene in a Chinese family affected with congenital insensitivity to pain with anhidrosis (CIPA).</p><p><b>METHODS</b>With informed consent obtained, peripheral blood samples were obtained from the patient and his family members. Seventeen coding exons and intron-exon boundaries of the NTRK1 gene were amplified with PCR and analyzed by direct sequencing.</p><p><b>RESULTS</b>A novel mutation c.2086_2087insC (p.Arg696 fsx) was identified in exon 16 of the NTRK1 gene in the proband. This insertion has caused open reading frame shifting and a premature termination has occurred just one codon downstream. Truncation of 72 amino acids at the C terminus has wiped out part of the tyrosine kinase domain (TKD) of the protein. Both of the proband's parents and two grandmothers have carried the c.2086_2087insC (p.Arg696 fsx) mutation. No mutation was found in the NTRK1 gene of other siblings.</p><p><b>CONCLUSION</b>Mutation analysis of the NTRK1 gene has been carried out in a Chinese family affected with CIPA, and a novel NTRK1 gene mutation was identified.</p>

Effect of Huannao Yicong prescription See Text extract on β-amyloid precursor protein metabolic signal transduction-related protein in brain tissue of dementia model transgenic mouse / 中国结合医学杂志

<p><b>OBJECTIVE</b>To observe the effect of Huannao Yicong Prescription (, HNYC, a Chinese medical compound) extract on β-amyloid precursor protein (APP) metabolic signal transduction related protein kinase C (PKC), tyrosine amyloid protein kinase (TrKA), and glycogen synthase kinase-3 (GSK-3) in brain tissue of transgenic mouse dementia model induced by APP.</p><p><b>METHODS</b>Sixty dementia model transgenic 3-month-old mice induced by APP695V717I were randomly allocated in four groups: the model group (A), the Donepezil (0.65×10(-3) g·kg(-1)·(-1))-treated group (B), and the two HNYC-treated groups (C and D) with high dosage (2.8 g·kg(-1)·(-1)) and low dosage (1.4 g·kg(-1)·(-1)) of HNYC extract, respectively, 15 mice in each group. Besides, a normal control group was set up with 15 C57BL/6J mice with the same age and genetic background as the model mice. The drugs for treatment were administered once a day by dissolving in equal-volume distilled water through gastric infusion, continued for 6 months, to mice in group A and to normal control group equal-volume distilled water was administered instead. Spatial learning and memory capacity of mice were observed by Morris water maze; their one-time escape response memory capacity was tested by diving platform; and changes of PKC, TrkA, and GSK-3 levels in hippocampus and cortex of brain were detected by Western blotting.</p><p><b>RESULTS</b>HNYC extract showed significant effects on increasing the time of model mice for swimming through the flat roof and the swimming time and path in the fourth quadrant P<0.05 or P<0.01). Diving platform test showed that the latent times in Groups B and C were longer than that in Group A significantly (P <0.05 and P<0.01). Compared with the normal control group, PKC and TrkA protein expression levels in hippocampus and cortex of model mice's brain lowered significantly (P<0.01), while GSK-3 protein expression increased significantly (P<0.01); compared with Group A (the model group), hippocampal and cortical levels of PKC protein expression in the intervened groups (B-D) as well as those of TrkA in Group C were higher (P<0.01 or P<0.05), while hippocampal levels of GSK-3 in intervened groups were lower (P<0.01).</p><p><b>CONCLUSION</b>HNYC extract could obviously increase the protein expressions of PKC and TrkA and decrease the expression of GSK-3 protein in brain tissue of transgenetic mice model of dementia, and regulate APP metabolic signal transduction path, and thus to suppress the production of Aβ, which is one of the dominant mechanisms for improving learning/memory capacity of dementia model animals.</p>

Responses of pancreatic cancer cells to stimulations by nerve growth factor and the role of Trk-A expression / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the responses of different pancreatic cancer cells to stimulations by nerve growth factor (NGF) and explore the role of Trk-A in such responses.</p><p><b>METHODS</b>Five pancreatic cancer cell lines (MIA-PaCa-2, PANC-1, SW-1990, AsPC-1, and BxPC-3) were exposed to different concentrations of NGF (0, 4, 20, 100, and 500 ng/ml). MTT and Matrigel invasion method were used to observe the changes in the cell proliferation and invasion ability. Trk-A expression in these cells was detected by PCR and Western blotting, and the relations of Trk-A expression to the cell proliferative and invasive abilities following NGF treatment were analyzed.</p><p><b>RESULTS</b>NGF at 100 ng/ml most obviously stimulated the cell proliferation, and PANC-1 cells showed the highest while AsPC-1 cells showed the least sensitivity to 100 ng/ml NGF stimulation. Matrigel invasion test showed that NGF enhanced the invasiveness of PANC-1 and MIA-PaCa-2 cells but produced only limited effect on AsPC-1 cells; the effect of NGF was completely inhibited by the Trk-A inhibitor CEP701. The expression levels of Trk-A mRNA and protein were the highest in PANC-1 cells and the lowest in AsPC-1 cells.</p><p><b>CONCLUSION</b>NGF can enhance the proliferation and invasiveness of pancreatic cancer cells, and this effect is possibly mediated by Trk-A protein.</p>

Crystal structure and functional implication of the RUN domain of human NESCA

NESCA, a newly discovered signaling adapter protein in the NGF-pathway, contains a RUN domain at its N-terminus. Here we report the crystal structure of the NESCA RUN domain determined at 2.0-Å resolution. The overall fold of the NESCA RUN domain comprises nine helices, resembling the RUN domain of RPIPx and the RUN1 domain of Rab6IP1. However, compared to the other RUN domains, the RUN domain of NESCA has significantly different surface electrostatic distributions at the putative GTPase-interacting interface. We demonstrate that the RUN domain of NESCA can bind H-Ras, a downstream signaling molecule of TrkA, with high affinity. Moreover, NESCA RUN can directly interact with TrkA. These results provide new insights into how NESCA participates in the NGF-TrkA signaling pathway.

Expression of NGF and TrkA in the brain of rats with intrauterine growth retardation / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the mechanism of brain development delay in rats with intrauterine growth retardation (IUGR) by examining the expression of nerve growth factor (NGF) and tyrosine kinase receptor A (Trk A) in the brain.</p><p><b>METHODS</b>Thirty-two pregnant rats were randomly fed with a normal diet (control group) or lower protein diet (IUGR group) during pregnancy (n=16 each). The pup rats were sacrificed at 0, 7, 14 or 21 days after birth. The protein levels of NGF and TrkA in the brain were determined by Western blot and immunohistochemistry staining.</p><p><b>RESULTS</b>The levels of NGF and TrkA in the brain in pup rats of the IUGR group were significantly lower than those in the control group 0, 7, 14 and 21 days after birth.</p><p><b>CONCLUSIONS</b>The decreased expression of protein levels of NGF and TrkA in the brain might be one of the causes of brain development delay in IUGR rats.</p>

Tyrosine kinase A and vascular endothelial growth factor receptor 2 in the invasion and metastasis of salivary adenoid cystic carcinoma / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To determine the effect of tyrosine kinase A (TrkA) and vascular endothelial growth factor receptor 2 (VEGFR2) in the invasion and metastasis of salivary adenoid cystic carcinoma (SACC).</p><p><b>METHODS</b>The expression of TrkA and VEGFR2 were detected by immunohistochemical staining in 47 cases of SACC of salivary glands. Clinical data were reviewed by multivariate prognostic analysis.</p><p><b>RESULTS</b>The positive rate of TrkA and VEGFR2 in SACC was 87.23% (41/47) and 85.11% (40/47) respectively. Express of TrkA and VEGFR2 in perineural invasion and recurrence group were higher than non-perineural invasion and non-recurrence group. Significant difference was found in microvessel density (MVD) and VEGFR2 expression within different groups (P < 0.05). MVD in perineural invasion group (25.14 +/- 2.83) was significantly higher than that in none perineural invasion group (18.81 +/- 1.33) (P < 0.05). MVD in recurrence or metastasis group (26.58 +/- 2.38) was significantly higher than that (19.06 +/- 1.39) in none recurrence nor metastasis group (P < 0.05).</p><p><b>CONCLUSION</b>Positive correlation between expression of TrkA, VEGFR2 and nerve invasion and vessel metastasis of SACC indicate that TrkA and VEGFR2 play important roles in the invasion and metastasis of SACC. It is possible that TrkA and VEGFR2 could be an aid for evaluating the prognosis of SACC patients.</p>

Expressions of neurotrophic factors and their receptors in prostate cancer / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the expressions of neurotrophic factors (NTFs) and their receptors in prostate cancer.</p><p><b>METHODS</b>We detected the expressions of the nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and their receptors TrkA, TrkB and p75 in 35 specimens of prostate cancer by Western blotting, and included 10 specimens of normal prostate tissue from young males that died accidentally.</p><p><b>RESULTS</b>Compared with the control group, the expressions of NGF and p75 were significantly decreased (P < 0.01), while those of BDNF, TrkA and TrkB significantly increased in prostate cancer (P < 0.05).</p><p><b>CONCLUSION</b>The changes in the expressions of NTFs and their receptors were related with the pathogenesis and progression of prostate cancer, which may be considered as reference indexes for the diagnosis of the disease.</p>