TERT activation targets DNA methylation and multiple aging hallmarks.

Insufficient telomerase activity, stemming from low telomerase reverse transcriptase (TERT) gene transcription, contributes to telomere dysfunction and aging pathologies. Besides its traditional function in telomere synthesis, TERT acts as a transcriptional co-regulator of genes pivotal in aging and age-associated diseases. Here, we report the identification of a TERT activator compound (TAC) that upregulates TERT transcription via the MEK/ERK/AP-1 cascade. In primary human cells and naturally aged mice, TAC-induced elevation of TERT levels promotes telomere synthesis, blunts tissue aging hallmarks with reduced cellular senescence and inflammatory cytokines, and silences p16INK4a expression via upregulation of DNMT3B-mediated promoter hypermethylation. In the brain, TAC alleviates neuroinflammation, increases neurotrophic factors, stimulates adult neurogenesis, and preserves cognitive function without evident toxicity, including cancer risk. Together, these findings underscore TERT's critical role in aging processes and provide preclinical proof of concept for physiological TERT activation as a strategy to mitigate multiple aging hallmarks and associated pathologies.

Senescence in Health and Disease.

Many cellular stresses activate senescence, a persistent hyporeplicative state characterized in part by expression of the p16INK4a cell-cycle inhibitor. Senescent cell production occurs throughout life and plays beneficial roles in a variety of physiological and pathological processes including embryogenesis, wound healing, host immunity, and tumor suppression. Meanwhile, the steady accumulation of senescent cells with age also has adverse consequences. These non-proliferating cells occupy key cellular niches and elaborate pro-inflammatory cytokines, contributing to aging-related diseases and morbidity. This model suggests that the abundance of senescent cells in vivo predicts "molecular," as opposed to chronologic, age and that senescent cell clearance may mitigate aging-associated pathology.

Increasing cell size remodels the proteome and promotes senescence.

Cell size is tightly controlled in healthy tissues, but it is unclear how deviations in cell size affect cell physiology. To address this, we measured how the cell's proteome changes with increasing cell size. Size-dependent protein concentration changes are widespread and predicted by subcellular localization, size-dependent mRNA concentrations, and protein turnover. As proliferating cells grow larger, concentration changes typically associated with cellular senescence are increasingly pronounced, suggesting that large size may be a cause rather than just a consequence of cell senescence. Consistent with this hypothesis, larger cells are prone to replicative, DNA-damage-induced, and CDK4/6i-induced senescence. Size-dependent changes to the proteome, including those associated with senescence, are not observed when an increase in cell size is accompanied by an increase in ploidy. Together, our findings show how cell size could impact many aspects of cell physiology by remodeling the proteome and provide a rationale for cell size control and polyploidization.

Physiological hypoxia restrains the senescence-associated secretory phenotype via AMPK-mediated mTOR suppression.

Cellular senescence is a state of stable proliferative arrest triggered by damaging signals. Senescent cells persist during aging and promote age-related pathologies via the pro-inflammatory senescence-associated secretory phenotype (SASP), whose regulation depends on environmental factors. In vivo, a major environmental variable is oxygenation, which varies among and within tissues. Here, we demonstrate that senescent cells express lower levels of detrimental pro-inflammatory SASP factors in physiologically hypoxic environments, as measured in culture and in tissues. Mechanistically, exposure of senescent cells to low-oxygen conditions leads to AMPK activation and AMPK-mediated suppression of the mTOR-NF-κB signaling loop. Finally, we demonstrate that treatment with hypoxia-mimetic compounds reduces SASP in cells and tissues and improves strength in chemotherapy-treated and aged mice. Our findings highlight the importance of oxygen as a determinant for pro-inflammatory SASP expression and offer a potential new strategy to reduce detrimental paracrine effects of senescent cells.

The senotherapeutic drug ABT-737 disrupts aberrant p21 expression to restore liver regeneration in adult mice.

Young mammals possess a limited regenerative capacity in some tissues, which is lost upon maturation. We investigated whether cellular senescence might play a role in such loss during liver regeneration. We found that following partial hepatectomy, the senescence-associated genes p21, p16Ink4a, and p19Arf become dynamically expressed in different cell types when regenerative capacity decreases, but without a full senescent response. However, we show that treatment with a senescence-inhibiting drug improves regeneration, by disrupting aberrantly prolonged p21 expression. This work suggests that senescence may initially develop from heterogeneous cellular responses, and that senotherapeutic drugs might be useful in promoting organ regeneration.

Blunting senescence boosts liver regeneration.

The mammalian liver possesses a unique capacity for regeneration. However, this regenerative potential declines with age due to unknown mechanisms. In this issue of Genes & Development, Ritschka and colleagues (pp. 489-494). compare liver regeneration upon partial hepatectomy in young and adult mice. Partial hepatectomy causes a transient increase in p21 in a subpopulation of hepatocytes that persists in adult mice. Remarkably, treatment with the BCL-2 family inhibitor ABT-737 blunts p21 expression, enhancing liver regeneration.

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.

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.

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.

Cellular senescence of granulosa cells in the pathogenesis of polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age, but its pathology has not been fully characterized and the optimal treatment strategy remains unclear. Cellular senescence is a permanent state of cell-cycle arrest that can be induced by multiple stresses. Senescent cells contribute to the pathogenesis of various diseases, owing to an alteration in secretory profile, termed 'senescence-associated secretory phenotype' (SASP), including with respect to pro-inflammatory cytokines. Senolytics, a class of drugs that selectively eliminate senescent cells, are now being used clinically, and a combination of dasatinib and quercetin (DQ) has been extensively used as a senolytic. We aimed to investigate whether cellular senescence is involved in the pathology of PCOS and whether DQ treatment has beneficial effects in patients with PCOS. We obtained ovaries from patients with or without PCOS, and established a mouse model of PCOS by injecting dehydroepiandrosterone. The expression of the senescence markers p16INK4a, p21, p53, γH2AX, and senescence-associated ß-galactosidase and the SASP-related factor interleukin-6 was significantly higher in the ovaries of patients with PCOS and PCOS mice than in controls. To evaluate the effects of hyperandrogenism and DQ on cellular senescence in vitro, we stimulated cultured human granulosa cells (GCs) with testosterone and treated them with DQ. The expression of markers of senescence and a SASP-related factor was increased by testosterone, and DQ reduced this increase. DQ reduced the expression of markers of senescence and a SASP-related factor in the ovaries of PCOS mice and improved their morphology. These results indicate that cellular senescence occurs in PCOS. Hyperandrogenism causes cellular senescence in GCs in PCOS, and senolytic treatment reduces the accumulation of senescent GCs and improves ovarian morphology under hyperandrogenism. Thus, DQ might represent a novel therapy for PCOS.

Evaluation of an E6/E7 PCR-capillary electrophoresis fragment analysis in the genotyping of human papillomavirus in archival FFPE samples of oropharyngeal cancer.

Accumulating evidence has demonstrated that high-risk human papillomaviruses (HR-HPVs) are involved in the etiology of a subset of oropharyngeal squamous cell carcinoma (OPSCC). In this regard, the International Agency for Research on Cancer (IARC) has recommended direct molecular HPV testing. So far, there is no agreement on the most appropriate method for HPV detection on OPSCC formalin-fixed paraffin-embedded (FFPE) materials. In this study, we aimed to evaluate the performance of the high-sensitive SureX HPV assay in OPSCC FFPE tissues compared with LiPA-25 and p16ink4a immunostaining. A retrospective series of FFPE primary OPSCC cases were diagnosed between 2008 and 2019 and provided by the Henan Cancer Hospital, China. The level of agreement of two assays was determined using Cohen's Kappa (κ) statistics. A total of 230 FFPE OPSCC samples from tumor resections (n = 160) and diagnostic biopsies (n = 70) were detected. Sixty-six (28.7%) and 70 (30.4%) samples were identified as HPV-DNA-positive by LiPA-25 and SureX, respectively, of which HPV16 was largely the most common type (95.5% vs 94.3%). We found a perfect concordance between LiPA-25 and SureX for HPV-DNA status (κ = 0.906, 95% CI: 0.875-0.937) and for HPV16 (κ = 0.925, 95% CI: 0.897-0.953). In addition, SureX and p16ink4a immunostaining had a perfect concordance (κ = 0.917, 95% CI: 0.888-0.946). Moreover, the HPV-driven fraction, based on double positivity for HPV-DNA and p16ink4a, was similar between SureX (63 of 230, 27.4%) and LiPA-25 (60 of 230, 26.1%). Similar results were found in samples from resections and biopsies. SureX and LiPA-25 are comparable. SureX could be used for routine HPV-DNA detection and genotyping on archival OPSCC FFPE tissues.

Correlation between high-risk HPV infection and p16/Ki-67 abnormalities in Pap samples in a South Eastern Europe cohort.

Cervical cancer (CC) is the fourth most common cause of cancer-related deaths amongst women worldwide. CC represents a major global healthcare issue, and Romania ranks the worst in mortality rates amongst EU countries. However, the early detection of CC can be lifesaving. To understand the testing process undergone by women in Romania, we performed a retrospective study, and investigated a cohort of 83 785 cervical cases from Romanian women aged 15-70, obtained in private-based opportunistic screening. We examined the correlation between Pap smear results, human papilloma virus (HPV) genotyping, and the expression of cell cycle markers p16 and Ki-67. Analysis of Pap results revealed approximately 10% abnormal cases, of which high-grade squamous intraepithelial lesions constituted 4.9%. HPV genotyping of 12 185 cases with available Pap results unveiled a range of high-risk HPV (hrHPV) types associated with cervical abnormalities. Notably, 26% of hrHPV-positive cases showed no observable abnormalities. In a subset of cases with abnormal Pap and a type of hrHPV, P16/Ki-67 double-staining was also positive. This study suggests the importance of an integrated diagnostic algorithm that should consider the HPV genotype, Pap smear, and p16/Ki-67 staining. This algorithm should enhance the CC screening accuracy and its management strategies, particularly in those regions with a high disease burden, such as Romania.

Should we use risk selection tests for HPV 16 and/or 18 positive cases: Comparison of p16/Ki67 and cytology.

Major screening abnormalities in precolposcopic stage are tests results that imply direct referral to colposcopy (and/or expedited treatment) without performing additional high-grade squamous intraepithelial lesions or worse (HSIL+) risk selection testing. Currently, both clinically validated HSIL+ risk selection tests, reflex cytology and reflex p16/Ki67 dual staining (DS), are being compared for use in primary human papillomavirus (HPV)-based screening to avoid possible overtreatment, but there is still no sufficient data available for their performance. Among 30 066 liquid-based cervical cancer screening tests results, a group of 332 women was selected with available high-risk types of HPV tests results with 16/18 limited genotyping, liquid-based cytology, DS, and histology results from standardized colposcopy with biopsy. In HPV 16/18+ cases, three triage approaches were retrospectively analyzed. Predictive values for detection of HSIL+ were calculated and number of colposcopies required in each strategy. Both triage models with DS used (reflex cytology followed by DS, and reflex DS alone in all cases) had significantly higher positive predictive value for HSIL+ than strategy with reflex cytology alone (44.2%/45.7% vs. 28.3%; p < 0.0001). In models with DS, less colposcopies were required (95/92 vs. 152) and less colposcopies were needed per HSIL+ detection (2.26/2.19 vs. 3.54). Only one HSIL+ case was missed in both triage models with DS incorporation. p16/Ki67 dual-stain may be an effective, alone or combined with cytology, triage test to detect HSIL+ in patients with major screening abnormalities in primary HPV-based cervical cancer screening. Performing cytology as the first triage test improves the strategy by enabling referrals to expedited treatment in selected cases.

Immunohistochemical p16 overexpression and Rb loss correlate with high-risk human papillomavirus infection in endocervical adenocarcinomas.

AIMS: p16 is a sensitive surrogate marker for transcriptionally active high-risk human papillomavirus (HR-HPV) infection in endocervical adenocarcinoma (ECA); however, its specificity is not perfect. METHODS AND RESULTS: We examined p16 and Rb expressions by immunohistochemistry (IHC) and the transcriptionally active HR-HPV infection by mRNA in-situ hybridisation (ISH) with histological review in 108 ECA cases. Thirteen adenocarcinomas of endometrial or equivocal origin (six endometrioid and seven serous carcinomas) were compared as the control group. HR-HPV was detected in 83 of 108 ECA cases (77%), including five HPV-associated adenocarcinomas in situ and 78 invasive HPV-associated adenocarcinomas. All 83 HPV-positive cases showed consistent morphology, p16 positivity and partial loss pattern of Rb. Among the 25 cases of HPV-independent adenocarcinoma, four (16%) were positive for p16, and of these four cases, three of 14 (21%) were gastric type adenocarcinomas and one of 10 (10%) was a clear cell type adenocarcinoma. All 25 HPV-independent adenocarcinomas showed preserved expression of Rb irrespective of the p16 status. Similarly, all 13 cases of the control group were negative for HR-HPV with preserved expression of Rb, even though six of 13 (46%) cases were positive for p16. Compared with p16 alone, the combination of p16 overexpression and Rb partial loss pattern showed equally excellent sensitivity (each 100%) and improved specificity (100 versus 73.6%) and positive predictive values (100 versus 89.2%) in the ECA and control groups. Furthermore, HR-HPV infection correlated with better prognosis among invasive ECAs. CONCLUSIONS: The results suggest that the combined use of p16 and Rb IHC could be a reliable method to predict HR-HPV infection in primary ECAs and mimics. This finding may contribute to prognostic prediction and therapeutic strategy.

First-in-human study of PSMA-targeting agent, [18F]AlF-P16-093: dosimetry and initial evaluation in prostate cancer patients.

PURPOSE: This is a first-in-human study to evaluate the radiation dosimetry of a new prostate-specific membrane antigen (PSMA)-targeted radiopharmaceutical, [18F]AlF-P16-093, and also initial investigation of its ability to detect PSMA-positive tumors using PET scans in a cohort of prostate cancer (PCa) patients. METHODS: The [18F]AlF-P16-093 was automatically synthesized with a GE TRACERlab. A total of 23 patients with histopathologically proven PCa were prospectively enrolled. Dosimetry and biodistribution study investigations were carried out on a subset of six (6) PCa patients, involving multiple time-point scanning. The mean absorbed doses were estimated with PMOD and OLINDA software. RESULTS: [18F]AlF-P16-093 was successfully synthesized, and radiochemical purity was > 95%, and average labeling yield was 36.5 ± 8.3% (decay correction, n = 12). The highest tracer uptake was observed in the kidneys, spleen, and liver, contributing to an effective dose of 16.8 ± 1.3 µSv/MBq, which was ~ 30% lower than that of [68Ga]Ga-P16-093. All subjects tolerated the PET examination well, and no reportable side-effects were observed. The PSMA-positive tumors displayed rapid uptake, and they were all detectable within 10 min, and no additional lesions were observed in the following multi-time points scanning. Each patient had at least one detectable tumor lesion, and a total of 356 tumor lesions were observed, including intraprostatic, lymph node metastases, bone metastases, and other soft tissue metastases. CONCLUSIONS: We report herein a streamlined method for high yield synthesis of [18F]AlF-P16-093. Preliminary study in PCa patients has demonstrated its safety and acceptable radiation dosimetry. The initial diagnostic study indicated that [18F]AlF-P16-093 PET/CT is efficacious and potentially useful for a widespread application in the diagnosis of PCa patients.

Determining the optimal pharmacokinetic modelling and simplified quantification method of [18F]AlF-P16-093 for patients with primary prostate cancer (PPCa).

PURPOSE: This paper discusses the optimization of pharmacokinetic modelling and alternate simplified quantification method for [18F]AlF-P16-093, a novel tracer for in vivo imaging of prostate cancer. METHODS: Dynamic PET/CT scans were conducted on eight primary prostate cancer patients, followed by a whole-body scan at 60 min post-injection. Time-activity curves (TACs) were obtained by drawing volumes of interest for primary prostatic and metastatic lesions. Optimal kinetic modelling involved evaluating three compartmental models (1T2K, 2T3K, and 2T4K) accounting for fractional blood volume (Vb). The simplified quantification method was then determined based on the correlation between the static uptake measure and total distribution volume (Vt) obtained from the optimal pharmacokinetic analysis. RESULTS: In total, 17 intraprostatic lesions, 10 lymph nodes, and 36 osseous metastases were evaluated. Visually, the contrast of the tumor increased and showed the steepest incline within the first few minutes, whereas background activity decreased over time. Full pharmacokinetic analysis revealed that a reversible two-compartmental (2T4K) model is the preferred kinetic model for the given tracer. The kinetic parameters K1, k3, Vb, and Vt were all significantly higher in lesions when compared with normal tissue (P < 0.01). Several simplified protocols were tested for approximating comprehensive dynamic quantification in tumors, with image-based SURmean (the ratio of tumor SUVmean to blood SUVmean) within the 28-34 min window found to be sufficient for approximating the total distribution Vt values (R2 = 0.949, P < 0.01). Both Vt and SURmean correlated significantly with the total serum prostate-specific antigen (tPSA) levels (P < 0.01). CONCLUSIONS: This study introduced an optimized pharmacokinetic modelling approach and a simplified acquisition method for [18F]AlF-P16-093, a novel PSMA-targeted radioligand, highlighting the feasibility of utilizing one static PET imaging (between 30 and 60 min) for the diagnosis of prostate cancer. Note that the image-derived input function in this study may not reflect the true corrected plasma input function, therefore the interpretation of the associated kinetic parameter estimates should be done with caution.

Podoplanin depletion in tonsil-derived mesenchymal stem cells induces cellular senescence via regulation of the p16Ink4a/Rb pathway.

BACKGROUND: Mesenchymal stem cells (MSCs) are widely used in the development of therapeutic tools in regenerative medicine. However, their quality decreases during in vitro expansion because of heterogeneity and acquired cellular senescence. We investigated the potential role of podoplanin (PDPN) in minimizing cellular senescence and maintaining the stemness of tonsil-derived MSCs (TMSCs). METHODS: TMSCs were isolated from human tonsil tissues using an enzymatic method, expanded, and divided into two groups: early-passaged TMSCs, which were cultured for 3-7 passages, and late-passaged TMSCs, which were passaged more than 15 times. The TMSCs were evaluated for cellular senescence and MSC characteristics, and PDPN-positive and -negative cells were identified by fluorescence-activated cell sorting. In addition, MSC features were assessed in siRNA-mediated PDPN-depleted TMSCs. RESULTS: TMSCs, when passaged more than 15 times and becoming senescent, exhibited reduced proliferative rates, telomere length, pluripotency marker (NANOG, OCT4, and SOX2) expression, and tri-lineage differentiation potential (adipogenesis, chondrogenesis, or osteogenesis) compared to cells passaged less than five times. Furthermore, PDPN protein levels significantly decreased in a passage-dependent manner. PDPN-positive cells maintained their stemness characteristics, such as MSC-specific surface antigen (CD14, CD34, CD45, CD73, CD90, and CD105) and pluripotency marker expression, and exhibited higher tri-lineage differentiation potential than PDPN-negative cells. SiRNA-mediated silencing of PDPN led to decreased cell-cycle progression, proliferation, and migration, indicating the significance of PDPN as a preliminary senescence-related factor. These reductions directly contributed to the induction of cellular senescence via p16Ink4a/Rb pathway activation. CONCLUSION: PDPN may serve as a novel biomarker to mitigate cellular senescence in the clinical application of MSCs.

High concordance of molecular subtyping between pre-surgical biopsy and surgical resection specimen (matched-pair analysis) in patients with vulvar squamous cell carcinoma using p16- and p53-immunostaining.

OBJECTIVE: Vulvar squamous cell carcinoma (VSCC) can be stratified into three molecular subtypes based on the immunoexpression of p16 and p53: HPV-independent p53-abnormal (p53abn) (most common, biologically aggressive), HPV-associated, with p16-overexpression (second most common, prognostically more favourable) and more recently recognised HPV-independent p53-wildtype (p53wt) (rarest subtype, prognostically intermediate). Our aim was to determine whether molecular subtypes can be reliably identified in pre-operative biopsies and whether these correspond to the subsequent vulvectomy specimen. METHODS: Matched-paired pre-surgical biopsies and subsequent resection specimen of 57 patients with VSCC were analysed for the immunohistochemical expression of p16 and p53 by performing a three-tiered molecular subtyping to test the accuracy rate. RESULTS: Most cases 36/57 (63.2%) belonged to the HPV-independent (p53-abn) molecular subtype, followed by HPV-associated 17/57 (29.8%) and HPV-independent (p53wt) 4/57 (7.0%). The overall accuracy rate on biopsy was 91.2% (52/57): 97.3% for p53-abnormal, 94.1% for p16-overexpression and 50% for p16-neg/p53-wt VSCC. Incorrect interpretation of immunohistochemical p53 staining pattern was the reason for discordant results in molecular subtyping in all five cases. In one case there was an underestimation of p53 pattern (wildtype instead of abnormal/aberrant) and in one case an overestimation of the p53 staining pattern (abnormal/aberrant instead of wildtype). In 3/5 there was a "double positive" staining result (p16 overexpression and abnormal/aberrant p53 staining pattern). In that cases additional molecular workup is required for correct molecular subtyping, resulting in an overall need for molecular examination of 3/57 (3.5%). CONCLUSIONS: Compared to the final resections specimen, the three-tiered molecular classification of VSCC can be determined on pre-surgical biopsies with a high accuracy rate. This enables more precise surgical planning, prediction of the response to (chemo) radiation, selection of targeted therapies and planning of the optimal follow-up strategy for patients in the age of personalised medicine.

Oncogene-induced senescence in meningiomas-an immunohistochemical study.

PURPOSE: Meningiomas are tumours originating from meningothelial cells, the majority belonging to grade 1 according to the World Health Organization classification of the tumours of the Central Nervous System. Factors contributing to the progression to the higher grades (grades 2 and 3) have not been elucidated yet. Senescence has been proposed as a potential mechanism constraining the malignant transformation of tumours. Senescence-associated beta-galactosidase (SA-ß-GAL) and inhibitors of cyclin-dependent kinases p16 and p21 have been suggested as senescence markers. METHODS: We analysed 318 meningiomas of total 343 (178 grade 1, 133 grade 2 and 7 grade 3). Tissue microarrays were constructed and stained immunohistochemically, using antibodies for SA-ß-GAL, p16 and p21. RESULTS: The positive correlation of the tumour grade with the expression of p16 (p = 0.016) and SA-ß-GAL (p = 0.002) was observed. The expression of p16 and SA-ß-GAL was significantly higher in meningiomas grade 2 compared to meningiomas grade 1 (p = 0.006 and p = 0.004, respectively). SA-ß-GAL positivity positively correlated with p16 and p21 in the whole cohort. In grade 2 meningiomas, a positive correlation was only between SA-ß-GAL and p16. Correlations of senescence markers in meningiomas grade 2 were not present. CONCLUSION: Our findings suggest the senescence activation in meningiomas grade 2 as a potential mechanism for the restraining of tumour growth and give hope for applying of promising senolytic therapy.

Three atypical/malignant onychopapillomas in a 52-case series with immunohistochemical study.

BACKGROUND: Onychopapilloma (OP) is a benign tumor of the nail. Haneke reported one case of malignant OP in 2021. No systematic immunohistochemistry study has been conducted on OP. The aim of our study was to identify possible malignant OP in our series of OP and to describe the immunohistochemical expression of p16, p53, and Ki67 in typical and atypical/malignant ones. METHODS: Ninety-one cases were available for pathological review. Immunohistochemical analysis could be performed on 52 cases. RESULTS: In 88 of 91 cases, the diagnosis of OP was confirmed. Three atypical/malignant cases were observed. No OP expressed p16. A normal p53 expression was observed in two thirds of the cases, an abnormal increased p53 expression in one third, including the three atypical cases. A normal Ki67 expression was observed in 84% of the cases, an abnormal Ki67 expression with focal heterogeneous expression in the suprabasal layers in 6% and in all suprabasal cell layers in 10%, including the three atypical cases. CONCLUSIONS: The diagnosis of atypical/malignant OP may be underestimated. The expression of Ki67 and p53 in these tumors differs from the expression observed in conventional OP. The absence of p16 expression confirms that human papillomavirus does not play a role in the etiopathogenesis of OP.