Biomarker expression and impact on clinical outcomes in an international study of chemoradiation and MRI-based image-guided brachytherapy for locally advanced cervical cancer: BIOEMBRACE.

PURPOSE: BIOEMBRACE-I was designed to study the impact of biomarkers in addition to clinic-pathological factors on disease outcomes in patients treated with chemoradiation and MRI-guided brachytherapy (BT) for locally advanced cervical cancer in EMBRACE study. PATIENT AND METHODS: Between 2018-2021, eight EMBRACE-I sites contributed tumour tissue for immunohistochemistry of p16, PD-L1 and L1CAM. These biomarkers and clinicopathological factors (FIGO 2009 stage, nodal status, histology, necrosis on MRI) were analysed to predict poor response at brachytherapy (BT) (high-risk clinical target volume [HR-CTV] ≥40cc) at BT), and 5-year local control, pelvic control and disease-free survival (DFS). Interaction between p16, PD-L1, radiotherapy dose (HR-CTV D90) and disease outcomes was investigated. Univariable and multivariable analysis were performed. RESULTS: Two-hundred sixty-four patients were included. The median HR-CTV D90 was 89 (86-95) Gy. p16 positive (pos), PD-L1>1% and L1CAM ≥ 10% was noted in 86.6%, 20.1% and 17.8% respectively. P16 negative (neg) status (OR 2.0 (1.0-5.7), p=0.04), necrosis on MRI (OR 2.1 (1.1-4.3), p<0.02) independently predicted for HR-CTV≥40cc, as did FIGO stage and tumour width >5cm. PDL1>1% was associated with reduced local (82% vs. 94%, p=0.02) and pelvic control (79% vs. 89%, p=0.02). HR-CTV D90 <85Gy was associated with inferior 5-year local control in p16+ patients especially if PD-L1 was co-expressed. On multivariable analysis, PD-L1>1% was the only independent factor for 5-year local control (HR 3.3, p=0.04) and L1CAM ≥50% for pelvic control (HR 5.5 (1.3-23.3), p =0.02). CONCLUSIONS: P16 neg status and tumor necrosis on MRI are independently associated with poor response to chemoradiation, whereas PD-L1>1% and L1CAM≥50% have an independent impact on local and pelvic control suggesting impact of biomarker expression on outcomes. Further validation is needed.

Upregulation of TET2 and Resistance to DNA Methyltransferase (DNMT) Inhibitors in DNMT1-Deleted Cancer Cells.

BACKGROUND: Ten-eleven-translocation (TET) 2 is a member of the TET family of proteins (TET1-3). DNMT1 gene deletion confers resistance to DNA methyltransferase (DNMT) inhibitors in colorectal, breast, and ovarian cancer cells. Currently, the effect of DNMT1 gene status on TET2 phenotype following DNMT inhibitor treatment is unclear in human malignancies. METHODS: Human colorectal carcinoma HCT116 cells (DNMT+/+) and their isogenic DNMT1 knockout (DNMT1-/-) counterpart were treated with DNMT inhibitors. Expression of TET2 and tumor suppressor (p16ink4A and p15ink4B) proteins were examined by Western blot. Apoptosis and CDKN2A promoter demethylation following drug treatment were detected by Annexin-V apoptosis assay and methylation-specific PCR. RESULTS: TET2 expression was robustly increased in DNMT1-/- cells by 0.5 µM and 5 µM decitabine and azacitidine treatment. Augmentation of TET2 expression was accompanied by re-expression of p16ink4A and p15ink4B proteins and CDKN2A promoter demethylation. TET2 upregulation and tumor suppressor re-expression were associated with resistance conferred by DNMT1 deletion. Treatment with 5-aza-4'-thio-2'-deoxycytidine at a low 0.5 µM dose only upregulated TET2 and reduced CDKN2A promoter methylation, and re-expression of p16ink4A in DNMT1-/- cells. DNMT inhibitors showed minimal effects on TET2 upregulation and re-expression of tumor suppressor proteins in cells with intact DNMT1. CONCLUSIONS: DNMT1 gene deletion made cancer cells prone to TET2 upregulation and activation of tumor suppressor expression upon DNMT inhibitor challenge. TET2 augmentation is concomitant with resistance to DNMT inhibitors in a DNMT1-deleted state.

The Diagnostic Accuracy of Electrical Impedance Spectroscopy-Assisted Colposcopy, HPV mRNA Test, and P16/Ki67 Immunostaining as CIN2+ Predictors in Greek Population.

OBJECTIVE: To evaluate the diagnostic accuracy of Electrical Impedance Spectroscopy (EIS)-assisted colposcopy in detecting CIN2+ Greek women towards standalone colposcopy, HPV mRNA testing, and p16/Ki67 immunostaining. METHODS: We conducted a cross-sectional observational study at the Cervical Pathology Clinic of the 2nd Obstetrics-Gynecology University Department of Hippokration Hospital Thessaloniki involving 316 patients from January 2022 to August 2023. All participants provided liquid-based cervical samples for cytology, HPV mRNA testing, and p16/Ki67 immunostaining. MAIN OUTCOME MEASURES: Subsequently, participants underwent both standalone colposcopy and EIS/ZedScan-assisted colposcopy, followed by cervical punch biopsies. RESULTS: The incorporation of EIS significantly enhanced the sensitivity of colposcopy, increasing it from 54.17% to 100%, equivalent to that of HPV mRNA testing and p16/Ki67 immunostaining, while achieving a high specificity (95.45%). The specificities observed with EIS/ZedScan-assisted and standalone colposcopy were notably superior to those of HPV-related biomarkers (HPV mRNA test and p16/Ki67 immunostaining). When compared to standalone colposcopy, HPV mRNA testing, and p16/Ki67 immunostaining, EIS/ZedScan-assisted colposcopy demonstrated the most favorable combination of Positive and Negative Predictive Values, at 90.57% and 100%, respectively. The inclusion of EIS/ZedScan in colposcopy led to the detection of 44 additional cases of true CIN2+ (100% of the total CIN2+ confirmed histologically) that were missed by standalone colposcopy. This discovery suggests a 45.83% increase in the detection of CIN2+ cases. CONCLUSIONS: The integration of EIS with colposcopy has demonstrated effectiveness in detecting cervical lesions, resulting in a significant detection increase of CIN2+ cases while offering optimal levels of sensitivity, specificity, and predictive values for CIN2+ detection.

Identification of immunosenescence of unconventional T cells in hepatocellular carcinoma.

Accumulation of senescent cells is a recognized feature in hepatocellular carcinoma (HCC), but their specific types and prognostic implications remain under investigation. This study aimed to delineate senescent cell types and their senescent patterns in HCC using publicly available bulk and single-cell mRNA sequencing data. Through gene expression and gene set enrichment analysis, we identified distinct senescent patterns within HCC samples. Notably, unconventional T cells, specifically natural killer T cells and γδT cells, were found to be the predominant senescent cell types. These cells exhibited enriched pathways related to DNA damage, senescence and the negative regulation of lymphocyte activation. Furthermore, we observed upregulation of the mTOR signaling pathway, which correlated positively with the expression of senescence-associated genes. This suggests a potential regulatory role for mTOR in the senescence of HCC. Strikingly, patients with elevated expression of senescence markers, including p16INK4A, p21, and GLB1, demonstrated significantly reduced overall survival rates. Our findings indicate that immunosenescence in unconventional T cells may play a role in HCC progression. The potential therapeutic implications of targeting the mTOR pathway or eliminating senescent unconventional T cells warrant further exploration to improve HCC patient outcomes.

Differences in Clinicopathological Features, P16Ink4a and P57KIP2 Immunohistochemical Expressions, and Survival Between Colorectal Carcinoma in Rectosigmoid and Other Colonic Locations.

Background One unique criterion of colorectal carcinoma (CRC) is the different locations within the colorectum. Different CRC sidedness/locations could have distinct criteria, including risk factors, morphological features, genetic alterations, prognostic factors, and clinical outcomes. Nearly half of the CRC cases occur in the rectal-sigmoid locations, while other colonic locations constitute the other half. Investigating specific protein expression patterns in the rectosigmoid CRC (rsCRC) compared to other colonic (ocCRC) locations helps understand the disease pathogenesis, predict prognosis, and design personalized treatments. This study is the first to compare P16Ink4a and P57KIP2 immunohistochemical (IHC) expression in rsCRC to ocCRC and examine their relationship to disease outcomes in both locations. Materials and methods A comparative cross-sectional study used tissue microarray slides from rsCRC and ocCRC that were immunohistochemically stained by anti-P16Ink4a and P57KIP2 antibodies. A semi-quantitative scoring system classified each marker's expression as positive or negative. The statistical analysis compared clinicopathological features, P16Ink4a and P57KIP2 expressions, and their relationship to clinical outcomes in rsCRC and ocCRC cases. Results One hundred fifty CRCs were distributed into the rsCRC cases (n=86, 57.3%) and the ocCRC cases (n=64, 42.7%). The rsCRC cases had a significantly lower age <40 years (P=0.002), higher frequency of mismatch repair (MMR) proficient status (P=0.003), and perineural invasion (P=0.008), with lower disease-free (DFS) and overall survival (OS) (P=0.03, and P=0.015, respectively). Significantly higher positive P16Ink4a and P57KIP2 IHC expressions were found in the rsCRCs compared to the ocCRCs (P=0.02, and P=0.03, respectively); however, their relationship to the hazards (HR) of recurrence (HR=4.02, P=0.058, and HR=0.36, P=0.14, respectively) and mortality (HR=2.56, P=0.21, and HR=0.23, P=0.58, respectively) in the rsCRC group was statistically nonsignificant. In the ocCRC group, P16Ink4a positivity was significantly associated with a higher disease recurrence and mortality hazard (HR=8.19, P=0.007, and HR=5.57, P=0.037, respectively), while P57KIP2 positivity was significantly associated with a lower mortality hazard (HR=0.12, P=0.027). Conclusion The rsCRCs differ from ocCRCs in clinicopathological criteria and protein expression patterns. Though P16Ink4a and P57KIP2 IHC expressions are higher in the rsCRC than in the ocCRC, their value as outcome predictors is higher in the ocCRCs rather than the rsCRCs. P16Ink4a and P57KIP2 can act as prognostic markers and be suitable targets for therapy modulation in the ocCRC group.

Immunohistochemistry staining of Eag1 and p16/Ki-67 can help improve the management of patients with cervical intraepithelial Neoplasia after cold knife conversion.

BACKGROUND: Immunohistochemistry (IHC) is widely used in the management of patients with cervical intraepithelial neoplasia (CIN) but still has many limitations in clinical practice. We analyzed the correlation of new biomarkers with the severity of CIN and follow-up outcomes in patients after conization to improve the management of patients with CIN. METHODS: IHC staining of Eag1 and p16/Ki-67 was performed on cervical tissue sections from 234 patients with suspected CIN2/3. After a series of follow-ups, including human papillomavirus (HPV) test and thinprep cytologic test (TCT) for 1-2 years, the outcomes were collected. IHC scores of biomarkers and follow-up results were used to analyze the correlation and assess the diagnostic efficiency of biomarkers. RESULTS: The IHC staining intensity of Eag1 and p16/Ki-67 was significantly different from that of the CIN1-3 groups (p < 0.05). Eag1 expression scores were significantly different in the distribution between the two follow-up groups (p < 0.001). ROC curves based on the correlations between the follow-up outcomes and the Eag1 scores and IS of p16/ki-67 showed that Eag1 had a greater AUC (0.767 vs. 0.666). Logistic regression analysis of the combination of biomarkers revealed a greater AUC value than any single biomarker. CONCLUSIONS: Eag1 expression was significantly correlated with CIN grade and follow-up outcomes after conization. IHC staining of combinations of biomarkers of Eag1, p16 and Ki-67 may help us to improve the ability to identify risk groups with abnormal follow-up outcomes after treatment for CIN.

CDKN2A copy number alteration in bladder cancer: Integrative analysis in patient-derived xenografts and cancer patients.

Bladder cancer (BlCa) is an extensively heterogeneous disease that leads to great variability in tumor evolution scenarios and lifelong patient surveillance, emphasizing the need for modern, minimally invasive precision medicine. Here, we explored the clinical significance of copy number alterations (CNAs) in BlCa. CNA profiling was performed in 15 patient-derived xenografts (PDXs) and validated in The Cancer Genome Atlas BlCa (TCGA-BLCA; n = 408) and Lindgren et al. (n = 143) cohorts. CDKN2A copy number loss was identified as the most frequent CNA in bladder tumors, associated with reduced CDKN2A expression, tumors of a papillary phenotype, and prolonged PDX survival. The study's screening cohort consisted of 243 BlCa patients, and CDKN2A copy number was assessed in genomic DNA and cell-free DNA (cfDNA) from 217 tumors and 189 pre-treatment serum samples, respectively. CDKN2A copy number loss was correlated with superior disease-free and progression-free survival of non-muscle-invasive BlCa (NMIBC) patients. Moreover, a higher CDKN2A index (CDKN2A/LEP ratio) in pre-treatment cfDNA was associated with advanced tumor stage and grade and short-term NMIBC progression to invasive disease, while multivariate models fitted for CDKN2A index in pre-treatment cfDNA offered superior risk stratification of T1/high-grade and EORTC high-risk patients, enhancing prediction of treatment outcome. CDKN2A copy number status could serve as a minimally invasive tool to improve risk stratification and support personalized prognosis in BlCa.

HPV status and immunohistochemical analysis of p16, p53 and PD­L1 expression as prognostic biomarkers in patients with squamous cell anal cancer receiving definitive radiotherapy/chemoradiotherapy.

Anal squamous cell carcinoma (SCC) treated with definitive radiotherapy (RT)/chemoradiotherapy (CRT) has shown high success rates, yet challenges such as treatment resistance and recurrence persist. The present study aimed to investigate the associations between immunohistochemical (IHC) evaluation, treatment response and prognosis in anal SCC. A retrospective cohort analysis included 42 patients with anal SCC treated at a single institution between 2006 and 2022. Human papillomavirus (HPV) status was determined, and the IHC analysis of p16, p53 and PD-L1 expression was conducted using formalin-fixed, paraffin-embedded biopsies. A complete response to RT/CRT was observed in 71.4% of patients. Recurrence occurred in 38.1% of cases, of which 7.1% had local-regional recurrence (LRR), 14.3% had distant recurrence (DR), and 16.7% had both LRR and DR. HPV positivity (71.4%) was significantly associated with p16 positivity. Lack of complete response was associated with HPV-negative status, p16-negative status, increased recurrence and DR. In addition, recurrence was significantly associated with p53-positive status, and p53 positivity was significantly associated with increased LRR. PD-L1 positivity, defined as a combined positive score (CPS) ≥1% was found in 73.8% of the patients, and exhibited significant associations with HPV positivity and p16 positivity. PD-L1 CPS ≥ 1% was also associated with an increased LRR. Univariate analysis revealed that age <65 years, a complete response and HPV positivity were associated with increased 5-year overall survival (OS), while a complete response, HPV positivity and p53-negative status were associated with increased 5-year disease-free survival (DFS). Multivariate analysis identified that age <65 years and HPV positivity are independent prognostic factors for 5-year OS, and a complete response and p53-negative status are independent prognostic factors for 5-year DFS. In conclusion, these findings suggust that the identification of HPV status and poor prognostic biomarkers at diagnosis may be used to guide personalized treatment strategies, with the combination of immunotherapy with standard CRT potentially providing improved outcomes.

Evaluation of prognostic biomarkers in meningiomas and their clinical implications in settings with limited resources.

Background: The 5th edition of the World Health Organization (WHO) Central Nervous System (CNS) tumor classification for meningiomas acknowledges the clinical relevance of genomic profiling studies and emphasizes the importance of incorporating molecular information alongside histopathological features, leading to more accurate diagnoses and improved patient care. Methods: We analyzed 206 meningioma samples (108 histological grade 1, 89 grade 2, and 9 grade 3) to study pTERT mutations, CDKN2A/B homozygous deletion, loss of H3K27me3, and p16 expression. The association of these molecular markers with survival outcomes was also assessed. Results: pTERT mutation was found in 4.85% of cases, predominantly occurring in histological grade 2 (11.24%), while none of the histological grade 1 or 3 meningiomas exhibited this mutation. CDKN2A/B gene deletion was absent in grade 1 and detected in 2.24% of grade2, and 33.3% of histological grade 3 cases. There was a significant increase in loss of H3K27me3 with higher tumor grades, while p16 loss was observed in over 50% of cases across all histological grades. The presence of pTERT mutation and CDKN2A/B homozygous deletion resulted in the reclassification of 5.33% (11/206) of meningiomas as integrated grade 3. pTERT mutation and CDKN2A/B deletion, emerged as prognostically relevant markers, showing significant differences in progression-free survival (PFS) between integrated grade 3 and histological grade 2 meningiomas (P = .0002). Conclusions: pTERT mutations are the most clinically relevant genetic alterations in meningiomas. Routine testing for pTERT mutations can identify high-risk cases of histologically grade 2 meningiomas, providing crucial prognostic information for treatment planning. CDKN2A/B alteration is rare and not cost-effective in assessing meningiomas. Immunohistochemical assessment of p16 and H3K27me3 expression lacks significant prognostic value. Assessment of pTERT mutations offers a cost-effective and valuable diagnostic tool for meningiomas.

Validation of immunohistochemical overexpression of p16 in the histologic diagnosis of cervical intraepithelial neoplasia grade 2.

An accurate cytohistologic diagnosis is important to avoid overtreatment of cervical intraepithelial lesions. The three-tiered Cervical Intraepithelial Neoplasia (CIN) classification, grades 1, 2 and 3, despite poor agreement among pathologists in diagnosing CIN2, is still being used. The College of American Pathologists recommended an alternative two-tiered classification that has not yet been universally accepted. We review the diagnostic results of 286 biopsies performed by three pathologists using haematoxylin and eosin (H&E) and p16 to establish the level of agreement among the readers. Agreement between pathologists in diagnosing CIN2 with H&E was around 45% and improved to 86.7% when interpreting p16 stained biopsies without H&E; agreement with pathologist 3 was lower, around 60%. Discrepant results from one pathologist when assessing p16 highlights the decisive influence of individual criteria. P16 has shown to improve agreement between pathologists with previous good agreement, but did not correct it for the third pathologist. In equivocal cases, protein p16 is a useful conjunctive tool for a histologic diagnosis.

Epidemiological trends and survival of oropharyngeal cancer in a high HPV-prevalent area: A Danish population-based study from 2000 to 2020.

Denmark, alongside other Scandinavian countries, the United States, Canada, and the United Kingdom, has high prevalence of human papillomavirus (HPV). Our oropharyngeal squamous cell carcinoma (OPSCC) database includes all diagnosed cases in Eastern Denmark during a period of more than two decades. We investigated the incidence, survival, and recurrence of patients with OPSCC with combined p16- and HPV testing covering a consecutive 21-year period. Age-adjusted incidence rate (AAIR) per 100,000, survival models, and Cox proportional-hazards model were employed. Two thousand eight hundred thirty-four patients were included (57.5% HPV positive (HPV+)/p16 positive (p16+), 33.7% HPV negative (HPV-)/p16 negative (p16-), 4% HPV+/p16-, and 4.8% HPV-/p16+). The AAIR for all patients increased from 1.8 to 5.1 per 100,000 from 2000 to 2020 linked to an increasing AAIR of HPV+/p16+ OPSCCs from 0.9 to 3.5 per 100,000 from 2000 to 2020. The AAIR for the HPV-/p16- OPSCCs decreased from 1.6 to 1.4 from 2017 to 2020. HPV+/p16+ OPSCCs had a higher 5-year overall survival (OS) of 79.2% compared to the other subgroups (HPV+/p16- OS: 50.4%; HPV-/p16+ OS: 49.4%; HPV-/p16- OS: 35.1%). The AAIR of the total OPSCC group increased from year 2000 to 2020, driven by a rise in the HPV+/p16+ group. A decreasing incidence rate was observed for the HPV-/p16- OPSCCs from 2017 to 2020. The OS for HPV+/p16+ OPSCCs was significantly higher compared to all other HPV/p16 subgroups. Therefore, we recommend testing for combined HPV and p16 status in patients with OPSCC when selecting patients for clinical trials, especially in case of de-escalating/escalating.

Influencing Factors of Survival in Hypopharyngeal Squamous Cell Cancer.

Objectives: This study examined the effects of various factors on survival in hypopharyngeal cancer, involving a total of 100 patients. Methods: Comorbidities, treatment modalities, survival times, and potential factors affecting survival were retrospectively analysed. The expression of p16 was also examined. A statistical analysis was conducted using IBM SPSS V25 software. Results: The mean overall survival time was determined to be 30.8 months. Smoking was observed in 95%, and regular alcohol consumption was reported in 75% of the cases. The expression of p16 did not significantly affect survival (p = 0.74) or the maximum tumour size (p = 0.21). The Kaplan-Meier method demonstrated significantly longer survival times (p = 0.047 *) in the group that underwent partial pharyngolaryngectomy with or without adjuvant therapy (median: 75.25 months, 95% CI: 31.57-118.93), compared to the other four treatment groups (i.e., total laryngectomy with pharyngectomy with or without adjuvant therapy, chemoradiation, chemotherapy, and radiotherapy). Conclusions: The study found that factors such as sex, comorbidities (e.g., type 2 diabetes and chronic obstructive pulmonary disease), TNM and stage, weight loss, smoking, and alcohol consumption did not have a significant effect on survival. In conclusion, the longest survival was observed after partial pharyngolaryngectomy with or without adjuvant therapy. Risk factors and comorbidities did not show a significant effect on survival. p16 expression was not a factor that affected either survival or tumour size.

Sodium valproate affects the expression of p16INK4a and p21WAFI/Cip1 cyclin­dependent kinase inhibitors in HeLa cells.

p16INK4a and p21WAF1/Cip1 are cyclin-dependent kinase inhibitors involved in cell cycle control, which can function as oncogenes or tumor suppressors, depending on the context of various extracellular and intracellular signals, and cell type. In human papillomavirus-induced cervical cancer, p16 INK4a shows oncogenic activity and functions as a diagnostic marker of cervical neoplasia, whereas p21 WAF1/Cip1 acts as a tumor suppressor and its downregulation is associated with the progression of malignant transformation. Several histone deacetylase (HDAC) inhibitors promote the positive and negative regulation of a number of genes, including p16 INK4a and p21 WAF1/Cip1; however, the effects of sodium valproate (VPA) on these genes and on the proteins they encode remain uncertain in HeLa cervical cancer cells. In the present study, these effects were investigated in HeLa cells treated with 0.5 or 2 mM VPA for 24 h, using reverse transcription-quantitative PCR, confocal microscopy and western blotting. The results revealed a decrease in the mRNA expression levels of p16 INK4a and a tendency for p16INK4a protein abundance to decrease in the presence of 2 mM VPA. By contrast, an increase in the protein expression levels of p21WAF1/Cip1 was detected in the presence of 0.5 and 2 mM VPA. Furthermore, VPA was confirmed to inhibit HDAC activity and induce global hyperacetylation of histone H3. Notably, VPA was shown to suppress p16 INK4a, a biomarker gene of cervical carcinoma, and to increase the abundance of the tumor suppressor protein p21WAF1/Cip1, thus contributing to the basic knowledge regarding the antitumorigenic potential of VPA. Exploration of epigenetic changes associated with the promoters of p16 INK4a and p21 WAF1/Cip1, such as histone H3 methylation, may provide further information and improve the understanding of these findings.

Taraxasterol exhibits dual biological effects on anti-aging and anti-cancer in lung cells.

As numerous countries around the world have entered an aging society currently, understanding the impact of aging on human health becomes critically important. Notably, aging is associated with increased prevalence of age-related diseases, with the lungs being particularly susceptible. Aging contributes to a decline in lung function, including respiratory disorders, inflammation, and oxidative stress. Therefore, it is a very important to identify and develop active substances that can mitigate lung cell aging. In current study, we evaluated the impact of Taraxasterol on lung cell senescence, showing that Taraxasterol can alleviate lung cell senescence, as evidenced by reductions in senescence-related marker molecules, including p16 and p21. Additionally, Taraxasterol was found to ameliorate inflammation and oxidative stress in lung cells. Further mechanistic studies indicated that Taraxasterol exerts anti-aging effects through the PGC1α/NRF1 signaling pathway in lung cell models. Since aging is also closely related to lung cancer, we also explored the potential anti-tumor effect of taraxasterol. Utilizing non-small cell lung cancer cells (NSCLC) as a model, we systematically study the anti-tumor effect of Taraxasterol both in vivo and in vitro. Our findings suggest that Taraxasterol exhibited anti-cancer effect through EGFR-mediated signaling. Taken together, Taraxasterol shows dual biological activities, offering promising anti-aging and anti-lung cancer benefits.

Hemizygous deletion of cyclin-dependent kinase inhibitor 2A/B with p16 immuno-negative and methylthioadenosine phosphorylase retention predicts poor prognosis in IDH-mutant adult glioma.

Background: Homozygous deletion of the tumor suppression genes cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) is a strong adverse prognostic factor in IDH-mutant gliomas, particularly astrocytoma. However, the impact of hemizygous deletion of CDKN2A/B is unknown. Furthermore, the influence of CDKN2A/B status in IDH-mutant and 1p/19q-codeleted oligodendroglioma remains controversial. We examined the impact of CDKN2A/B status classification, including hemizygous deletions, on the prognosis of IDH-mutant gliomas. Methods: We enrolled 101 adults with IDH-mutant glioma between December 2002 and November 2021. CDKN2A/B deletion was evaluated with multiplex ligation-dependent probe amplification (MLPA). Immunohistochemical analysis of p16/MTAP and promoter methylation analysis with methylation-specific MLPA was performed for cases with CDKN2A/B deletion. Kaplan - Meier plots and Cox proportion hazards model analyses were performed to evaluate the impact on overall (OS) and progression-free survival. Results: Of 101 cases, 12 and 4 were classified as hemizygous and homozygous deletion, respectively. Immunohistochemistry revealed p16-negative and MTAP retention in cases with hemizygous deletion, whereas homozygous deletions had p16-negative and MTAP loss. In astrocytoma, OS was shorter in the order of homozygous deletion, hemizygous deletion, and copy-neutral groups (median OS: 38.5, 59.5, and 93.1 months, respectively). Multivariate analysis revealed hazard ratios of 9.30 (P = .0191) and 2.44 (P = .0943) for homozygous and hemizygous deletions, respectively. Conclusions: CDKN2A/B hemizygous deletions exerted a negative impact on OS in astrocytoma. Immunohistochemistry of p16/MTAP can be utilized to validate hemizygous or homozygous deletions in combination with conventional molecular diagnosis.

Characterizing the amyloid core region of the tumor suppressor protein p16INK4a using a limited proteolysis and peptide-based approach.

The human tumor suppressor p16INK4a is a small monomeric protein that can form amyloid structures. Formation of p16INK4a amyloid fibrils is induced by oxidation which creates an intermolecular disulfide bond. The conversion into amyloid is associated with a change from an all α-helical structure into ß-sheet fibrils. Currently, structural insights into p16INK4a amyloid fibrils are lacking. Here, we investigate the amyloid-forming regions of this tumor suppressor using isotope-labeling limited-digestion mass spectrometry analysis. We discover two key regions that likely form the structured core of the amyloid. Further investigations using thioflavin-T fluorescence assays, electron microscopy and solution nuclear magnetic resonance spectroscopy of shorter peptide regions confirm the self-assembly of the identified sequences that include methionine and leucine repeat regions. This work describes a simple approach for studying protein motifs involved in the conversion of monomeric species into aggregated fibril structures. It provides first insights into the polypeptide sequence underlying the core structure of amyloid p16INK4a formed after a unique oxidation-driven structural transition.

Comparing loss of p16 and MTAP expression in detecting CDKN2A homozygous deletion in pleomorphic xanthoastrocytoma.

Pleomorphic xanthoastrocytomas (PXAs) harbor CDKN2A homozygous deletion in >90% of cases, resulting in loss of p16 expression by immunohistochemistry. Considering the proximity of MTAP to CDKN2A and their frequent concurrent deletions, loss of MTAP expression may be a surrogate for CDKN2A homozygous deletion. We evaluated p16 and MTAP expression in 38 patient PXAs (CNS WHO grade 2: n = 23, 60.5%; grade 3: n = 15, 39.5%) with available chromosomal microarray data to determine whether MTAP can be utilized independently or in combination with p16 to predict CDKN2A status. CDKN2A, CDKN2B, and MTAP homozygous deletion were present in 37 (97.4%), 36 (94.7%), and 25 (65.8%) cases, respectively. Expression of p16 was lost in 35 (92.1%) cases, equivocal in one (2.6%), and failed in 2 (5.3%), while MTAP expression was lost in 27 (71.1%) cases, retained in 10 (26.3%), and equivocal in one (2.6%). This yielded a sensitivity of 94.6% for p16 and 73.0% for MTAP in detecting CDKN2A homozygous deletion through immunohistochemistry. MTAP expression was lost in the 2 cases with failed p16 staining (combined sensitivity of 100%). Our findings demonstrate that combined p16 and MTAP immunostains correctly detect CDKN2A homozygous deletion in PXA, while MTAP expression alone shows reduced sensitivity.

Human papillomavirus prevalence, genotype distribution, and prognostic factors of vaginal cancer.

We aimed to investigate human papillomavirus (HPV) prevalence and genotype distribution and prognostic factors in vaginal cancer (VC). VC patients who received treatment between 1989 and 2020 were retrospectively reviewed. L1 general polymerase chain reaction (PCR) followed by HPV Blot (King Car, I-Lan, Taiwan) and E6 type-specific-PCR were performed for genotyping firstly. P16 and p53 immunohistochemistry staining was performed. Univariate and multivariate analyses identified predictors of clinical outcomes.79 VC patients were eligible for analysis. 73 patients (92.4%) were squamous cell carcinoma (SCC) and 6 (7.6%) as non-SCC. The median follow-up time was 134.3 months (range 0.9-273.4). Among nine initially HPV-negative cases, seven were identified as being positive through HPV16/18/45/52/58 whole-genome amplification followed by Sanger sequencing (WGASS). HPV DNA sequences were detected in 98.6% of SCC and 83.3% of non-SCC, respectively, with HPV16 (49.4%), HPV52 (15.2%) and HPV58 (8.9%) being predominant. Patients with paraaortic lymph node (LN) metastasis had a 5-year cancer-specific survival (CSS) rate of 0%. Multivariate analysis revealed that only p16 and stage were significantly correlated with prognosis. Variables with strong correlations (p16- and HPV-positivity, LN metastasis and stage), were included in models 2-5 alternatively. Stage III/IV (hazard ratio [HR] = 3.64-4.56) and LN metastasis (HR = 2.81-3.44) were significant negative predictors of CSS, whereas p16-positivity (HR = 0.29-0.32) and HPV-positivity (HR = 0.14) were related to better prognosis. In conclusion, 97.5% of VCs were HPV-positive with WGASS. Stage III/IV and LN metastasis were significant negative predictors, whereas p16- and HPV-positivity were significantly associated with better prognosis.

Study of Expression of P16 in Premalignant and Malignant Lesions of Penis and Their Significance.

Background & Objective: Penile squamous cell carcinoma (SCC) is an extremely rare malignancy. It is usually caused by chronic human papillomavirus (HPV) 16 and HPV 18 infections. This study was conducted to investigate the immunohistochemical overexpression of p16, a surrogate marker for HPV, and to evaluate its usefulness as a potential diagnostic biomarker. Methods: In this cross-sectional prospective and retrospective cohort study, 56 penile squamous cell carcinoma (SCC) specimens and five penile premalignant specimens were evaluated in Kasturba Medical College, Mangalore, India, from January 2013- December 2018 in terms of clinical and histopathological features. Immunohistochemical expression for p16 in cases and controls was evaluated. Statistical comparison of p16 expression among clinical features, histological subtype, grade, and stages of tumor were done. Results: Analysis of the pattern of p16 staining showed diffuse and strong nuclear and cytoplasmic expression in 32.8% of the cases. There was a highly significant association (P<0.001) of pattern of p16 expression among the HPV and non-HPV subtypes of penile carcinoma. p16 expression was not significantly associated with other prognostic parameters like site of the lesion, lymphovascular invasion, perineural invasion, histologic grade, and pathologic stage. Conclusion: Expression of p16 would be a useful tool in differentiation between the HPV-associated and non-HPV-associated subtypes of penile SCC that may be helpful in prediction of aggressiveness and invasive potential of the respective histologic subtypes.