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.

Molecular genetics of papillary thyroid carcinoma: great expectations...

Papillary thyroid carcinoma (PTC) is the most prevalent type of endocrine cancer and, in recent epidemiological surveys, one of the types of human cancer whose incidence is growing. Despite the favourable outcome and long survival rates of most patients, some tumours display an aggressive behaviour and may progress to the highly aggressive and lethal, anaplastic thyroid carcinoma. In recent years, several progresses have been made on the molecular characterization of PTC, in general, and in the genetic alterations underlying the histotype diversity of this type of cancer, in particular. This holds true regarding alterations on nuclear DNA as well as mitochondrial DNA. In this review we have summarized the most recent findings in the genetic characterization of PTC, giving a particular emphasis to the genotype-phenotype associations, the prognosis implications, and the diagnostic and therapeutic value of the newly identified genetic markers.

O carcinoma papilífero de tireóide (CPT) é o tipo mais prevalente de câncer endócrino e, em pesquisas epidemiológicas recentes, um dos tipos de câncer humano cuja incidência vêm crescendo. A despeito do prognóstico favorável e da longa taxa de sobrevivência da maioria dos pacientes, alguns tumores mostram um comportamento agressivo e podem progredir para o altamente agressivo e letal carcinoma anaplásico de tireóide. Recentemente, vários progressos foram feitos quanto à caracterização molecular do CPT, em general, e às alterações genéticas subjacentes à diversidade histológica desse tipo de câncer, em particular, particularmente com respeito às alterações dos DNAs nuclear e mitocondrial. Nesta revisão, nós sumarizamos os achados mais recentes da caracterização genética do CPT, dando ênfase particular às associações genótipo-fenótipo, às implicações prognósticas e ao valor diagnóstico e terapêutico dos marcadores genéticos recentemente identificados.