[Methylthioadenosine phosphorylase and p16 as surrogate diagnostic markers for CDKN2A homozygous deletion in brain tumors].

Objective: To examine whether immunohistochemistry of methylthioadenosine phosphorylase (MTAP) and p16 could be used to predict the CDKN2A status in various brain tumors. Methods: A total of 118 cases of IDH-mutant astrocytomas, 16 IDH-wildtype glioblastoma, 17 polymorphic xanthoastrocytoma (PXA) and 20 meningiomas diagnosed at Xuanwu Hospital, Capital Medical University, Beijing, China from November 2017 to October 2023 were collected and analyzed. The CDKN2A status was detected by using fluorescence in situ hybridization or next-generation sequencing. Expression of MTAP and p16 proteins was detected with immunohistochemistry. The association of loss of MTAP/p16 expression with CDKN2A homozygous/heterozygous deletion was examined. Results: Among the 118 cases of IDH-mutant astrocytoma, 13 cases showed homozygous deletion of CDKN2A. All of them had no expression of MTAP while 9 cases had no expression of p16. Among the 16 cases of IDH wild-type glioblastoma, 6 cases showed homozygous deletion of CDKN2A. All 6 cases had no expression of MTAP, while 3 of these cases had no expression of p16 expression. Among the 17 PXA cases, 4 cases showed homozygous deletion of CDKN2A, and the expression of MTAP and p16 was also absent in these 4 cases. Among the 20 cases of meningiomas, 4 cases showed homozygous deletion of CDKN2A. Their expression of MTAP and p16 was also absent. Among the four types of brain tumors, MTAP was significantly correlated with CDKN2A homozygous deletion (P<0.05), with a sensitivity of 100%. However, it was only significantly correlated with the loss of heterozygosity (LOH) of CDKN2A in astrocytomas (P<0.001). P16 was associated with CDKN2A homozygous deletion in IDH-mutant astrocytoma and PXA (P<0.001), but not with the LOH of CDKN2A. Its sensitivity and specificity were lower than that of MTAP. Conclusions: MTAP could serve as a predictive surrogate for CDKN2A homozygous deletion in adult IDH-mutant astrocytoma, PXA, adult IDH-wildtype glioblastoma and meningioma. However, p16 could only be used in the first two tumor types, and its specificity and sensitivity are lower than that of MTAP.

[Pay attention to molecular pathological diagnosis of pediatric glioma].

Glioma is one of the most common central nervous system tumors in children.Increasing studies show that compared with adults, some gliomas in children have unique molecular genetic characteristics and completely different biological behaviors, although they are similar to adults in morphology and nomenclature. Therefore, pediatric glioma is by no means a "miniature version" of adults. In the 5th edition of WHO classification of central nervous system tumors published in the end of 2021, one of the most important revisions is the division of the classification into adult-type and pediatric-type diffuse gliomas, and the latter is further divided into pediatric-type diffuse low-grade gliomas and pediatric-type diffuse high-grade gliomas. In addition to histological morphology and clinical features, the basis of classification includes more molecular features. Therefore, in clinical practice, we need to pay more attention to the significance of molecular pathological diagnosis in the diagnosis and treatment of gliomas in children.

[Clinicopathological features and molecular characteristics of tall cell and hobnail variants of papillary thyroid carcinoma].

Objective: To investigate the clinicopathological and molecular genetic characteristics of tall cell variant and hobnail variant of papillary thyroid carcinoma (PTC). Methods: Twenty-one cases of tall cell variant (TCV-PTC) of PTC (TCV-PTC) and ten cases of hobnail variant of PTC (HV-PTC), as the highly aggressive group, were collected from Xuanwu Hospital from August 2009 to August 2015. Twenty-two cases of follicular variant and 21 classical PTC cases were included as control. Relevant clinical and pathologic data were obtained, and in some cases, paraffin samples were selected for gene mutation spectrum analysis using second generation sequencing. Results: There were 18 males and 56 females; 57 patients were younger than 55 years of age, and 17 patients were 55 years or older. The mean tumor size was 1.6 cm for the high-aggressive group (TCV-PTC and HV-PTC), 1.1 cm for the follicular subtype, and 1.6 cm for the classical type. There were 54 cases with thyroid capsule invasion, 24 cases with extra-thyroidal invasion, and 45 patients with lymph node metastases. Regional recurrence occurred in 7 cases, no recurrence in 54 cases, and 13 patients were lost to follow-up. The highly aggressive group was more likely to show extra-thyroidal invasion, lymph node metastases and recurrence than those with classical PTC (P<0.05). Within this cohort, BRAF V600E mutation was detected in 53 cases and TERT promoter mutation in 6 cases. Compared with the single mutation group and no mutation group, BRAF and TERT promoter co-mutation group was more commonly detected in older age, male, larger tumor size and more prone to extra-thyroid invasion (P<0.05). In addition, among BRAF and TERT co-mutation cases, the highly-aggressive group accounted for the highest proportion (5/6). Conclusions: TCV-PTC and HV-PTC, as highly-aggressive variants of PTC, show more aggressive biologic behavior (more lymph node metastasis, external thyroid invasion and recurrences) than the classical and follicular variants of PTC. Coexisting BRAF and TERT promoter mutations may be associated with invasive biologic behavior.

[Extraskeletal mesenchymal chondrosarcoma in central nerve system: a clinicopathological analysis].

Objective: To investigate the clinicopathological features, immunophenotype, molecular genetics and prognosis of extraskeletal mesenchymal chondrosarcoma in central nerve system (CNS). Methods: The clinicopathological findings, immunohistochemistry and genetic analysis of four cases of extraskeletal mesenchymal chondrosarcoma in Xuanwu Hospital between 2014 and 2019 were reviewed and followed up. Results: The ages of patients ranged from 20-35 years. Three patients had intracranial lesions and one had intradural tumor. The characteristic histologic features were undifferentiated small cells together with scattered islands of hyaline cartilage. There was hemangiopericytoma-like pattern with calcification and ossification. The tumor cells were positive for VIM and SOX9; and the small cells were positive for CD99, NSE and NKX3.1. The cells in chondroid matrix were positive for S-100. All tumor cells were negative for markers including CKpan, EMA and desmin. At molecular analysis, HEY1-NCOA2 fusion transcripts were identified in three patients. The fusion points were between exon 4 of HEY1 and exon 13 of NCOA2. Follow-up information was obtained in two patients, and both were free from recurrence or metastasis at 8 and 20 months. Conclusions: Extraskeletal mesenchymaI chondrosarcoma is a rare CNS disease with poor prognosis. In addition to SOX9, NKX3.1 can be another useful antibody for the differential diagnosis. The combination of pathological characteristics, immunophenotype and genetic profile of tumor is essential for diagnosis.

[Chordoid glioma: a clinicopathological study].

Objective: To analyze the clinicopathological features of chordoid glioma. Methods: A total of 12 cases of chordoid gliomas from 2009 to 2020 in Xuanwu Hospital of Capital Medical University and General Hospital of Chinese People's Liberation Army were retrospectively analyzed. The clinical and imaging characteristics, pathologic and molecular characteristics were analyzed, and the relevant literature was reviewed. Results: All 12 patients (4 males and 8 females) aged from 25 to 67 years (mean 39 years) and mainly had a history of headache or/and vision loss. MRI showed that the lesions located in the third ventricle, and they showed abnormal enhancement. Pathologically, these 12 cases displayed the morphologic characteristics of chordoid gliomas, including papillary structures in two cases. Immunohistochemically, GFAP and vimentin were expressed in all 12 cases (12/12). TTF1 was also expressed in all cases (10/10). CD34 and CKpan were seen in 11 cases (11/12). EMA with dot-and/or-ring like positivity was seen in 9 cases (9/10). Tissues were available in nine chordoid gliomas for Sanger sequencing to detect PRKCA and IDH gene mutation, and eight cases (8/9) showed PRKCA gene D463H mutation. None of these cases showed IDH1 R132 and IDH2 R172 mutation. All 12 patients underwent surgery, and four were lost to follow up. The remaining eight patients were progression or recurrence free at last follow-up in January 2021. Conclusions: Chordoid gliomas have relatively distinguishing clinical and histopathological features. PRKCA gene mutation in chordoid gliomas can be considered as a biomarker for the diagnosis and differential diagnosis of chordoid gliomas, and may provide a direction for future targeted therapy.

[Clinicopathological features of diffuse leptomeningeal glioneuronal tumor].

Objective: To investigate the clinicopathological features, diagnosis and prognosis of diffuse leptomeningeal glioneuronal tumor (DLGNT). Methods: Five cases of DLGNT diagnosed from January 2016 to January 2020 were collected from Xuanwu Hospital, Capital Medical University. The clinical features, histopathologic characteristics, immunohistochemical and molecular genetic findings and prognosis were analyzed and the relevant literature was reviewed. Results: The five patients (two males and three females) were aged 2 to 52 years (median 11 years), and had history of increased intracranial pressure (headache and vomiting) or limb weakness. Three of them were younger than 16 years of age. The imaging studies showed diffuse intracranial and intraspinal nodular leptomeningeal thickening and enhancement, with or without parenchymal involvement. At times there were associated small cyst-like lesions. Imaging interpretations were inflammatory lesions in three cases and space occupying lesions in two. Microscopically, in three cases the tumors showed low to moderate cellularity, consisting of relatively monomorphous oligodendrocyte-like cells arranged in small nests or diffusely distribution. No mitosis and necrosis were observed. In two cases there were increased cellularity with a diffuse honeycomb pattern. The tumor showed mild to moderate polymorphism with hyperchromatic nuclei. Mitosis, endothelial vascular proliferation and glomeruloid vessels were seen. Necrosis was absent. The tumor cells in all five cases were positive for synaptophysin,Olig2 and negative for IDH1 and H3 K27M. GFAP was focally positive in four cases and only one case expressed NeuN partly. The Ki-67 labeling index was 1%-35%. BRAF fusion was detected in four cases. Genetic analysis showed solitary 1p deletion in two cases (2/5), while all cases were negative for 1p/19q co-deletion (0/5). The five patients were followed up for 13 to 28 months (median 15 month). One patient died after 27 months. There was no evidence of tumor progression in the remaining four patients. Conclusions: DLGNT is rare and easily confused with other central nervous system tumors and inflammatory lesions. Therefore, the diagnosis of DLGNT should be made based on comprehensive information including imaging, morphologic and corresponding immunohistochemical examinations and molecular genetics to avoid misdiagnosis and delay in management.

[Clinicopathological and molecular genetic characteristics of adult IDH wild-type diffuse gliomas].

Objective: To analyze the clinicopathological and molecular features and prognostic implications of adult isocitrate dehydrogenase wild type (IDH-wt) diffuse gliomas. Methods: A total of 87 cases of adult IDH-wt diffuse gliomas from 2016 to 2020 in Xuanwu Hospital of Capital Medical University were retrospectively collected. The clinicopathological characteristics and prognosis were analyzed. Molecular characteristics were also analyzed using Sanger sequencing and next generation sequencing. Results: There were 53 males and 34 females, aged from 19 to 78 years (mean 53 years). Histopathologically, there were 63 (72.4%) glioblastomas, 16 (18.4%) anaplastic astrocytomas, six (6.9%) diffuse astrocytomas, and one (1.1%) each of anaplastic oligodendrocytoma, and anaplastic oligodendroglioma. Common molecular genetic changes in IDH-wt gliomas included TERT promoter mutation which was found in 60 cases (69.0%); MGMT promoter methylation in 43 cases (49.4%); EGFR mutation in 38 cases (43.7%); PTEN mutation in 35 cases (40.2%) and TP53 mutation in 32 cases (36.8%). In addition, PDGFRA mutation was detected in 17 cases (19.5%), CDK4 amplification in 15 cases (17.2%) and MDM2 amplification in 11 cases (12.6%). In IDH-wt diffuse gliomas, there was no significant difference in the overall survival between TERT promoter, EGFR, PTEN, TP53, PDGFRA, CDK4, MDM2 mutations and the wild-type, since these gene mutations could co-occur in any case (P>0.05). Also there was no significant difference in the overall survival between the WHO grade Ⅱ/Ⅲ gliomas and glioblastoma patients with these gene mutations (P>0.05). Conclusions: TERT promoter, EGFR, PTEN, TP53, PDGFRA, CDK4 and MDM2 gene mutations are common molecular genetic changes in adult IDH-wt gliomas, and are associated with poor prognosis. It is suggested that these genes are potentially useful for predicting the prognosis and should be tested in adult IDH-wt gliomas.

[High-grade gliomas with H3 G34R mutation: a clinicopathological study].

Objective: To analyze the clinicopathological features and probable mechanisms of high-grade gliomas with H3 G34R mutation. Methods: Five cases of high-grade gliomas with H3 G34R mutation were collected at Xuanwu Hospital, Capital Medical University, Beijing, China, from 2016 to 2019. The clinical and pathological data for each case was retrospectively reviewed. Results: The 5 patients (2 males and 3 females) aged from 15 to 45 years (mean 23 years), and had a history of headache or motor weakness. Four of them were younger than 20 years of age. Magnetic resonance imaging showed that the lesions of 3 cases were seen separately in frontal lobe, parietal lobe or temporal lobe, 1 case involved both frontal lobe and parietal lobe, and otherwise multiple lobes were involved in 1 case. Contrast enhancement could be observed in 2 cases. Pathological examination showed that glioblastoma was the most common entity, with or without primitive neuronal component. All 5 cases showed that H3 G34R was diffusely positive in tumor nuclei with ATRX loss. Moreover, p53 was overexpressed in 4 cases. None of them showed Olig2 expression. Two patients showed disease progression after surgery at 18 months and 24 months, respectively. The latter of the two deceased 3 months after tumor progression. Conclusions: The clinicopathological and molecular genetics features of high-grade gliomas with H3 G34R mutation have relatively similar clinicopathological and genetic features, and more commonly seen in young adults (vs. older adults). Thus, these tumors may be discussed further as a distinct tumor entity.

Probiotic Supplementation and Food Intake and Knowledge Among Patients and Consumers.

The consumption of probiotics has gained popularity, highlighting the importance for consumers and clinicians to be aware of their compositions and health effects. The primary objective was to determine incentives for taking probiotics and knowledge about probiotic composition among consumers of various education levels, ethnicities, and locations. A secondary objective was to determine brands, dosages, prices, advertised benefits, and refrigeration status of commercially available probiotics in the Sacramento region. This was a voluntary anonymous online survey conducted from May to August 2017. Surveys were administered at the University of California Davis (UCD) Dermatology Clinic, as well as at approved locations within a 100-mi. radius. Data analysis was performed at the UCD Dermatology clinic. Eligible participants age 18 years and older were asked to complete a voluntary anonymous online survey. A random sample of participants were recruited from the UCD Dermatology clinic, local schools, and health food stores within the designated parameters. We collected 396 surveys, 97% of which were completed. Of those surveyed, 39.4% have previously taken probiotics, 44.6% could identify at least one species present in their supplement, 42.5% could identify the number of strains, and 33.0% could identify the dosage. Gut health was the most common reason for taking probiotics (58.1%). Most rated price as important when purchasing probiotics (70.3%). Although probiotic use is prevalent in Sacramento, most people are unfamiliar with the composition of their supplement. More evidence is needed to guide consumers in making more educated decisions.

[Implication of BRAF V600E and CTNNB1 gene mutations in the pathological classification of craniopharyngioma].

Objective: To investigate the clinicopathological significance of BRAF V600E and CTNNB1 gene mutations in adamantinomatous craniopharyngiomas (ACP) and papillary craniopharyngiomas (PCP). Methods: The retrospective study included a total of 67 craniopharyngiomas diagnosed from October 2009 to August 2018 at Xuanwu Hospital, Capital Medical University. The immunohistochemical staining for ß-catenin and BRAF V600E expression, Sanger sequencing of exon 3 of CTNNB1, BRAF mutation analysis by scorpions amplification refractory mutation system (ARMS) fluorescence quantitative PCR were performed. Univariate survival analysis was used to correlate with tumor recurrence. Results: Of the 67 patients, 53 were ACPs and 14 were PCPs. Four patients underwent multiple operations and one of them presented with malignant transformation into squamous cell carcinoma. Histologically, ACPs were characterized by whorl-like cell clusters, peripheral palisaded layer, stellate reticulum, finger-shaped protrusions, ghost cells and wet keratinous substances. While PCPs usually consisted of mature squamous epithelium associated with fibrovascular stroma resulting in papillary appearance. The nuclear immunopositivity for ß-catenin was observed in 73.6% (39/53) of ACPs, and it was absent in PCPs (0/14). The nuclear translocation of ß-catenin usually presented at whorl-like structures or around ghost cells. Of all the cases, mutations analysis in exon 3 of ß-catenin gene CTNNB1 were successful in 46 cases and 42.1% (16/38) of ACP showed CTNNB1 gene mutation, while none of the PCPs harbored CTNNB1 gene mutation (0/8). The cytoplasmic immunopositivity for BRAF V600E mutant protein was found in all PCPs (14/14) and negative in all ACPs (0/53). ARMS-PCR results showed that BRAF V600E mutations were observed in 13/14 of PCPs but not seen in ACPs (0/53). Follow-up data were available in 35 patients with duration of 2 to 120 months. Ten patients experienced recurrences after the first surgery. Upon univariate survival analysis, only subtotal excision was found to be associated with increased recurrence (P=0.032), while pathological type, postoperative radiotherapy and CTNNB1 gene mutation were not (P>0.05). Conclusions: There is significant difference in the expression of BRAF V600E and CTNNB1 genes between ACP and PCP, and their immunohistochemical and molecular detection therefore can be used in the diagnosis and differential diagnoses of craniopharyngiomas.

[Expression and bioinformatics analysis of long-chain non-coding RNA PVT1 in tumors].

Objective: To study the expression and mechanism of long-chain non-coding RNA PVT1 in tumor by bioinformatics analysis and experimental verification, and to provide new ideas for the study of the pathogenesis of tumors. Methods: The expression of PVT1 in 14 common tumors was downloaded from starBase v2.0 public database, which also was verified by PVT1 RNA-in situ hybridization.The upstream transcription factors, the downstream target microRNA(miRNA) for PVT1 and the target genes for the target miRNAs were predicted and analyzed by using bioinformatics based on the database of UCSC Genome Browser, HMDD v2.0, miRTar Base, JASPAR databases. Results: StarBase database analysis and RNA in situ hybridization showed that PVT1 was highly expressed in kidney clear cell carcinoma and colon and rectal adenocarcinoma. PVT1 was regulated by the upstream transcription factors CREB1, Atf1, SP1, KLF5, STAT3, while it could control the expression of the downstream target miR-16. bcl-2, VEGFA, CCNE1, CCND1 and SHOC2 showed an interaction with the transcription factor of PVT1, which formed a feedback regulatory pathway. Conclusions: PVT1 is highly expressed in kidney clear cell carcinoma and colon and rectal adenocarcinoma.The predictive analysis of bioinformatics demonstrates that transcription factor/PVT1/miR-16/target gene signal axon may be an important molecular mechanism, which provide a valuable clue for further functional mechanism research of long-chain non-coding RNA.

Nornicotine, a nicotine metabolite and tobacco alkaloid: desensitization of nicotinic receptor-stimulated dopamine release from rat striatum.

Nornicotine, a major tobacco alkaloid and nicotine metabolite, accumulates in rat brain in pharmacologically relevant concentrations following repeated nicotine administration. Nornicotine-evoked striatal dopamine release is Ca2+-dependent, stereoselective and sensitive to nicotinic receptor antagonists, indicating nicotinic receptor-mediation. The present study determined if S-(-)-nornicotine desensitizes nicotinic receptors and if cross-desensitization to S-(-)-nicotine occurs. S-(-)-Nicotine (10 and 100 nM) diminished [3H]overflow from [3H]dopamine-preloaded rat striatal slices following subsequent superfusion with 10 microM S-(-)-nicotine (46% and 74%, respectively) or 10 microM S-(-)-nornicotine (59% and 81%, respectively). S-(-)-Nornicotine (1 and 10 microM) diminished the response to subsequent superfusion with 10 microM S-(-)-nornicotine (85% and 97%, respectively) or 10 microM S-(-)-nicotine (82% and 88%, respectively). Thus, similar to S-(-)-nicotine, S-(-)-nornicotine desensitizes nicotinic receptors. but with approximately 12-fold lower potency. Cross-desensitization suggests involvement of common nicotinic receptor subtypes. Therefore, S-(-)-nicotine metabolites, such as nornicotine, have neuropharmacologically relevant effects.