p16INK4a Expression Research Articles

ROS-Induced Gingival Fibroblast Senescence: Implications in Exacerbating Inflammatory Responses in Periodontal Disease.

Periodontal disease is the pathological outcome of the overwhelming inflammation in periodontal tissue. Cellular senescence has been associated with chronic inflammation in several diseases. However, the role of cellular senescence in the pathogenesis of periodontal disease remained unclear. This study aimed to investigate the role and the mechanism of cellular senescence in periodontal disease. Using single-cell RNA sequencing, we first found the upregulated level of cellular senescence in fibroblasts and endothelial cells from inflamed gingival tissue. Subsequently, human gingival fibroblasts isolated from healthy and inflamed gingival tissues were labeled as H-GFs and I-GFs, respectively. Compared to H-GFs, I-GFs exhibited a distinct cellular senescence phenotype, including an increased proportion of senescence-associated β-galactosidase (SA-β-gal) positive cells, enlarged cell morphology, and significant upregulation of p16INK4A expression. We further observed increased cellular reactive oxygen species (ROS) activity, mitochondrial ROS, and DNA damage of I-GFs. These phenotypes could be reversed by ROS scavenger NAC, which suggested the cause of cellular senescence in I-GFs. The migration and proliferation assay showed the decreased activity of I-GFs while the gene expression of senescence-associated secretory phenotype (SASP) factors such as IL-1β, IL-6, TGF-β, and IL-8 was all significantly increased. Finally, we found that supernatants of I-GF culture induced more neutrophil extracellular trap (NET) formation and drove macrophage polarization toward the CD86-positive M1 pro-inflammatory phenotype. Altogether, our findings implicate that, in the inflamed gingiva, human gingival fibroblasts acquire a senescent phenotype due to oxidative stress-induced DNA and mitochondrial damage, which in turn activate neutrophils and macrophages through the secretion of SASP factors.

Stiffening symphony of aging: Biophysical changes in senescent osteocytes.

Senescent osteocytes are key contributors to age-related bone loss and fragility; however, the impact of mechanobiological changes in these cells remains poorly understood. This study provides a novel analysis of these changes in primary osteocytes following irradiation-induced senescence. By integrating subcellular mechanical measurements with gene expression analyses, we identified significant, time-dependent alterations in the mechanical properties of senescent bone cells. Increases in classical markers such as SA-β-Gal activity and p16Ink4a expression levels confirmed the senescence status post-irradiation. Our key findings include a time-dependent increase in cytoskeletal Young's modulus and altered viscoelastic properties of the plasma membrane, affecting the contractility of primary osteocytes. Additionally, we observed a significant increase in Sclerostin (Sost) expression 21 days post-irradiation. These biophysical changes may impair osteocyte mechanosensation and mechanotransduction, contributing to bone fragility. This is the first study to time-map senescence-associated mechanical changes in the osteocyte cytoskeleton. Our findings highlight the potential of biophysical markers as indicators of cellular senescence, providing more specificity than traditional, variable biomolecular markers. We believe these results may support biomechanical stimulation as a potential therapeutic strategy to rejuvenate aging osteocytes and enhance bone health.

Adolescents and young adults with sickle cell disease exhibit accelerated aging with elevated T-cell p16INK4a expression.

People living with sickle cell disease (SCD) experience complications indicative of an accelerated aging phenotype typified by early decline in physical function and increased risk for age-related conditions. Cellular senescence, measured by expression of p16INK4a in peripheral T-lymphocytes, is recognized as one of the underlying contributors to organismal aging. To examine if cellular senescence is increased in SCD patients, we cross-sectionally measured and compared expression of p16 mRNA in peripheral blood T lymphocytes in 18 adolescents and young adults with SCD to 27 similarly aged individuals without SCD. Expression of p16 was dramatically higher in individuals with SCD vs. without SCD (10.1 vs. 8.7 log2 p16 units, respectively, p < 0.001) - a gap of 43 years in biological age - consistent with accelerated aging in the SCD population. Race was not associated with the increased p16 expression in the SCD group. These initial results suggest that individuals with SCD have a significantly higher cellular senescence burden which may contribute to premature aging, physiological decline, and excess morbidities. Additional longitudinal assessment and consideration for trials of senolytic therapies among individuals living with SCD and high p16 expression are warranted to improve their health span.

P16Ink4a-induced senescence in cultured mast cells as a model for ageing reveals significant morphological and functional changes

BackgroundMast cells (MCs) are tissue resident cells of the immune system, mainly known for their role in allergy. However, mounting evidence indicates their involvement in the pathology of age-related diseases, such as Alzheimer’s disease, Parkinson’s disease, and cancer. MC numbers increase in aged tissues, but how ageing affects MCs is poorly understood.ResultsWe show that MC ageing is associated with the increased expression of the cell cycle inhibitor p16 Ink4a, a marker and inducer of cellular senescence. Relying on this observation and the tight association of ageing with senescence, we developed a model of inducible senescence based on doxycycline-induced expression of p16Ink4a in cultured bone marrow derived MCs (BMMCs). Using this model, we show that senescent MCs upregulate IL-1β, TNF-α and VEGF-A. We also demonstrate that senescence causes marked morphological changes that impact MC function. Senescent MCs are larger, contain a larger number of secretory granules (SGs) and have less membrane protrusions. Particularly striking are the changes in their SGs, reflected in a significant reduction in the number of electron dense SGs with a concomitant increase in lucent SGs containing intraluminal vesicles. The changes in SG morphology are accompanied by changes in MC degranulation, including a significant increase in receptor-triggered release of CD63-positive extracellular vesicles (EVs) and the exteriorisation of proteoglycans, as opposed to a gradual inhibition of the release of β-hexosaminidase.ConclusionsThe inducible expression of p16Ink4a imposes MC senescence, providing a model for tracking the autonomous changes that occur in MCs during ageing. These changes include both morphological and functional alterations. In particular, the increased release of small EVs by senescent MCs suggests an enhanced ability to modulate neighbouring cells.

HPV is an essential driver in recurrence of cervical cancer

IntroductionHigh-risk human papillomavirus (HPV) has been detected in distant metastases from cervical cancer (CC) patients, suggesting a role of HPV. Material and methodsHere, we included 26 patients with recurrence of CC (2019–2023). With next generation sequencing (NGS) and immunohistochemical staining, primary and recurrent tissues were analyzed for HPV DNA and HPV RNA, p16INK4a expression, and somatic TP53 and RB1 mutations. ResultsAll primary and corresponding recurrent tissues were HPV DNA and HPV RNA positive. Within the same tissue, we found complete DNA/RNA agreement in 25/26 (96.2 %) primary and 25/25 (100 %) recurrent tissues, and partial agreement in the remaining sample. There was complete agreement between primary and recurrent tissue in 23/26 (88.5 %) and 23/25 (92.0 %) patients on DNA and RNA, respectively, whereas the remaining showed partial agreement with two genotypes detected in primary and only one of these in recurrent tissue. Except for one sample, all samples from high-risk HPV-positive patients were p16INK4a positive. The low-risk HPV11-positive patient was p16INK4a negative and had a pathogenic TP53 mutation, while the remaining samples were TP53/RB1 mutation negative. ConclusionIn high-risk HPV-positive CC patients, HPV seems to play a role in recurrent disease. Our findings support ongoing research on targeting HPV oncogenes in CC, also in metastatic disease.

Mitochondrial fatty acid oxidation drives senescence.

Cellular senescence is a stress-induced irreversible cell cycle arrest involved in tumor suppression and aging. Many stresses, such as telomere shortening and oncogene activation, induce senescence by damaging nuclear DNA. However, the mechanisms linking DNA damage to senescence remain unclear. Here, we show that DNA damage response (DDR) signaling to mitochondria triggers senescence. A genome-wide small interfering RNA screen implicated the outer mitochondrial transmembrane protein BNIP3 in senescence induction. We found that BNIP3 is phosphorylated by the DDR kinase ataxia telangiectasia mutated (ATM) and contributes to an increase in the number of mitochondrial cristae. Stable isotope labeling metabolomics indicated that the increase in cristae enhances fatty acid oxidation (FAO) to acetyl-coenzyme A (acetyl-CoA). This promotes histone acetylation and expression of the cyclin-dependent kinase inhibitor p16INK4a. Notably, pharmacological activation of FAO alone induced senescence both in vitro and in vivo. Thus, mitochondrial energy metabolism plays a critical role in senescence induction and is a potential intervention target to control senescence.

Activation of ALDH2 alleviates hypoxic pulmonary hypertension in mice by upregulating the SIRT1/PGC-1α signaling pathway

To investigate whether activation of mitochondrial acetal dehydrogenase 2 (ALDH2) alleviates hypoxic pulmonary hypertension by regulating the SIRT1/PGC-1α signaling pathway. Thirty 8-week-old C57 BL/6 mice were randomized into control, hypoxia, and hypoxia +Alda-1 (an ALDH2 activator) group (n=10), and the mice in the latter two groups, along with 10 ALDH2 knockout (ALDH2-/-) mice, were exposed to hypoxia (10% O2, 90% N2) with or without daily intraperitoneal injection of Alda-1 for 4 weeks. The changes in right ventricular function and pressure (RVSP) of the mice were evaluated by echocardiography and right ventricular catheter test, and pulmonary artery pressure was estimated based on RVSP. Pulmonary vascular remodeling, right ventricular injury, myocardial α -SMA expression, distal pulmonary arteriole muscle normalization, right ventricular cross-sectional area, myocardial cell hypertrophy, and right cardiac hypertrophy index were assessed with HE staining, immunofluorescence staining and WGA staining, and the expressions of ALDH2, SIRT1, PGC-1α, P16INK4A and P21CIP1 were detected. In pulmonary artery smooth muscle cells with hypoxic exposure, the effect of Alda-1 and EX527 on cell senescence and protein expressions was evaluated using β-galactose staining and Western blotting. The wild-type mice with hypoxic exposure showed significantly increased RVSP, right ventricular free wall thickness and myocardial expressions of P16INK4A and P21CIP1, which were effectively lowered by treatment with Alda-1 but further increased in ALDH2-/- mice. In cultured pulmonary artery smooth muscle cells, hypoxic exposure significantly increased senescent cell percentage and cellular expressions of P16INK4A and P21CIP1, which were all lowered by treatment with Alda-1, but its effect was obviously attenuated by EX527 treatment. ALDH2 alleviates hypoxiainduced senescence of pulmonary artery smooth muscle cells by upregulating the SIRT1/PGC-1α signaling pathway to alleviate pulmonary hypertension in mice.

Association of Senescence Markers with Age and Allograft Rejection in Renal Transplant Recipients.

Renal transplantation is the treatment of choice for patients with end-stage renal disease. In the last decade, the number of older renal transplant recipients has significantly increased. However, these patients are at a higher risk of developing post-transplant complications. Therefore, identifying the suitable biomarkers to predict which older patients are at risk of complications is crucial. Cellular senescence could provide insights into the increased vulnerability in this population and guide personalized post-transplant care. This preliminary study involved biopsies from 25 patients with renal allograft rejection and 18 patients without rejection, further divided into older (50-65 years) and younger (29-40 years) groups. Biopsies were collected at different time points after transplantation, and rejection was classified according to the histological Banff 07 criteria. Additionally, immunohistochemistry for the markers of cellular senescence, p27kip1 and p16INK4a, was performed. We observed that the number of p27kip1-positive glomeruli was higher in the older patients with rejection compared to the younger patients with rejection, and a similar pattern was found in the patients without rejection. However, the number of p27kip1-positive tubules was higher in the older patients with rejection compared to the younger patients with rejection, as well as compared to both the older and younger patients without rejection. Tubular p16INK4a expression was not significantly different in the older patients with rejection compared to the younger patients with rejection, and the same pattern was observed in the patients without rejection. However, it was increased in the older patients with rejection in comparison to the older patients without rejection. Our preliminary data suggest the strong potential of both p16INK4a and p27kip1 as biomarkers of renal graft rejection, particularly in older renal transplant recipients.

A Cross Sectional Study on the Expression of MIB-1 and P16INK4a in Oral Carcinoma in a Tertiary Care Hospital

Background: Oral cancer is one of most prevalent cancer with high morbidity and mortality rate in India. Around 90% are squamous cell carcinomas among the oral cancers. Uncontrolled proliferation of cell is considered to be the key processes of oncogenesis. MIB-1 or Ki67 is expressed in all proliferating cells and used as a tool for estimating the percentage of dividing cells within a tumor. In addition to it, MIB-1 acts as a potentially prognostic marker in oral malignancies. Materials and Methods: Around 100 cases of oral squamous cell carcinoma were assessed for nuclear atypia, mitotic activity and necrosis. For Ki-67, strong nuclear positivity was seen as favorable. There were three grades: 1 for 10–30%, 2 for 30–50%, and 3 for 50% and above. The number of positive cells and staining intensity for p16 (nuclear or/and cytoplasmic staining) were computed. Results: Ki-67 and p16 expressions were seen in oral squamous cell carcinomas that are well, moderately, and poorly differentiated. Ki-67 expression increased when grades rose from well differentiated to poorly differentiated carcinoma. p16 had a better expression in well differentiated carcinoma compared to poorly differentiated carcinoma. The mean mitotic count, were increased in high grade neoplasms. Conclusions: Therefore, the expression of p16 and Ki-67 in malignant lesions of the oral squamous cell carcinoma can be used in conjunction with the histomorphological attributes to research their capacity for proliferation of oral malignancies.

6612 Both Overt And Mild Hypercortisolism Accelerate Biological Aging

Abstract Disclosure: K. Yu: None. J. Saini: None. J.N. Farr: None. F. Vanessa: None. S. Khosla: None. I. Bancos: Advisory Board Member; Self; AstraZeneca, Adrenas, Neurocrine, Spruce, Recordati, Xeris, Novo Nordisk, HRA Pharmaceuticals, Sparrow, Diurnal, Corcept. Research Investigator; Self; HRA Pharmaceuticals, Recordati. Importance: Patients with both mild autonomous cortisol secretion (MACS) and overt Cushing syndrome (CS) demonstrated high prevalence of aging-related morbidity and an increased mortality. Objective: To determine whether p16INK4a in T cell, a cell cycle enzyme that associated with chronological aging and cell senescence, is associated with hypercortisolism and hypercortisolism-related comorbidities. Design, Setting, and Participants: In this single-center cross-sectional study, we prospectively recruited consecutive patients with hypercortisolism between July 1, 2020 and August 24 2022. Patients were included if they were diagnosed with Cushing syndrome (CS) or mild autonomous cortisol secretion (MACS). Age- (± 2 years) and sex-matched referent subjects without known adrenal disorders were included if abdominal imaging was available. Participants on exogenous glucocorticoids within 3 months prior were excluded. Exposure: Presence of hypercortisolism (MACS and CS). Main Outcomes and Measures: Primary outcomes included p16INK4a, advanced glycation end products (AGE) reader result, Frailty Index score, frailty (defined as frailty index&amp;gt;0.31), and physical performances in patients and matched referents at index date. Secondary outcomes included correlation between biological age markers, hormonal workup and the risk of comorbidities. p16INK4a expression analysis was adjusted for age, sex, smoking, and alcohol use for all analyses except for associations with CVD and frailty. Results: Of 85 patients (87% women, mean age 53 years), 51 (60%) had MACS (34 had matched referents), 34 (40%) had overt CS (16 had matched referents). Patients with CS demonstrated a median 1.9-fold higher p16INK4a expression (P&amp;lt;.001), and patients with MACS showed a median of 1.70-fold p16INK4a expression (P=.013), when compared to referent subjects. Age- and sex-adjusted p16INK4a expression was associated with frailty index score (r=0.23, P=.035), time-up-and-go test (r=0.28, P=.048), gait speed (r=-0.36, P=.035), but not with AGE reader result, 6-minute walk test, or hand grip measurement. The p16INK4a expression was associated with history of cardiovascular disease (age-adjusted odds ratio (aOR)=3.70, 95% confidence interval (CI), 1.20-11.43) and frailty (aOR=2.27, 95%CI, 1.04-4.98). Conclusion and relevance: We demonstrated evidence of cell senescence in both patients with CS and patients with MACS. Further studies need to determine the impact of surgical, cortisol-lowering, and senolytic medical therapies in MACS on cell senescence and associated aging-related comorbidities. Presentation: 6/1/2024

7581 Periodic Administration of Quercetin and Dasatinib Alleviates Skeletal Fragility in the INS2AKITA Mouse Model of Type 1 Diabetes

Abstract Disclosure: R. Dresner-Pollak: Consulting Fee; Self; Opko Biologics LTD.. Speaker; Self; Medison Pharma. N. Lishinsky: None. I. Gurt: None. J. Stokar: None. V. Temkin: None. P. Shivam: None. G. Zatarah: None. J. Milgram: None. R. Shahar: None. Skeletal fragility is a recognized complication of type 1 diabetes (T1D). The risk of hip and non-vertebral fractures is significantly higher in people living with T1D compared to age- and sex-matched non-diabetic controls and those living with type 2 diabetes (T2D). Hip fracture risk is up to six-fold higher in T1D patients; hip fractures occur 10-15 years earlier and the outcome is poorer compared to non-diabetics. Alterations in bone quality are considered major contributors to T1D-related skeletal fragility. As people with T1D live longer, there is a growing need to discover new therapeutics to reduce fracture risk. TID is associated with accelerated biological aging. Cellular senescence is a fundamental mechanism of aging. Senescent cells stop dividing, are resistant to apoptosis and acquire a distinct phenotype that includes secretome changes termed “senescence-associated secretory phenotype” (SASP). Clearing senescent cells with senolytics is recognized as a promising therapeutic approach for multiple conditions in mice and humans We explored the ability of senolytics dasatinib (D), a tyrosine kinase inhibitor, and quercetin (Q), a flavanol, present in fruit and vegetables, drug combination, to alleviate femur fragility in mice with T1D. Ins2Akita mice show a sexual dimorphic effect of the mutant Ins2 allele causing severe hyperglycemia in males. We treated Ins2Akita male and female mice and C57BL/6 wild type (WT) male mice with D + Q administered once monthly for four months beginning at age 3 months. 3-month-old Ins2Akita male mice had higher blood levels of the SASPs components HMGB1, PAI-1, MMP12, and increased gene expression of p53 and senescence effectors p16, p15 and SASPs Il1b, Mmp3, Mmp9, Mmp13, Serpineb2 at the femur diaphysis and in bone marrow mesenchymal stem cells, respectively compared to age-matched WT male mice. In vitro, exposure to glucose levels equivalent to those observed in blood in Ins2Akita male mice induced cellular senescence in IDG-SW3 osteocyte-like cells including a 4-5-fold increase in gene expression of p16INK4a, p21Cip[1], p53, double percentage of SA-β-gal+ cells and P21 protein level. Ingenuity pathway analysis of differentially expressed proteins revealed enrichment for the senescence pathway (Z=1.213; P=1.11E-05). D+Q administration did not affect bone microarchitecture at the spine (L2), distal femur metaphysis and diaphysis assessed by µCT. D+Q administration significantly increased femur resistance to fracture assessed by the 3-point-bending test by increasing whole femur work-to-fracture, the ultimate parameter of bone resistance to failure, and post-yield displacement, an index of matrix composition, organization, and bone quality in Ins2Akita males. No effect was observed in Ins2Akita females or WT male mice, indicating that the intervention is specific for T1D. Senolyitcs D+Q show promise in improving bone health in T1D. Presentation: 6/1/2024

The impact of alternate-day fasting on the salivary gland stem cell compartments in non-obese diabetic mice with newly established Sjögren's syndrome.

Intermittent fasting exerts a profound beneficial influence on a spectrum of diseases through various mechanisms including regulation of immune responses, elimination of senescent- and pathogenic cells and improvement of stem cell-based tissue regeneration in a disease- and tissue-dependent manner. Our previous study demonstrated that alternate-day fasting (ADF) led to alleviation of xerostomia and sialadenitis in non-obese diabetic (NOD) mice, a well-defined model of Sjögren's syndrome (SS). This present study delved into the previously unexplored impacts of ADF in this disease setting and revealed that ADF increases the proportion of salivary gland stem cells (SGSCs), defined as the EpCAMhi cell population among the lineage marker negative submandibular gland (SMG) cells. Furthermore, ADF downregulated the expression of p16INK4a, a cellular senescence marker, which was concomitant with increased apoptosis and decreased expression and activity of NLRP3 inflammasomes in the SMGs, particularly in the SGSC-residing ductal compartments. RNA-sequencing analysis of purified SGSCs from NOD mice revealed that the significantly downregulated genes by ADF were mainly associated with sugar metabolism, amino acid biosynthetic process and MAPK signaling pathway, whereas the significantly upregulated genes related to fatty acid metabolic processes, among others. Collectively, these findings indicate that ADF increases the SGSC proportion, accompanied by a modulation of the SGSC property and a switch from sugar- to fatty acid-based metabolism. These findings lay the foundation for further investigation into the functionality of SGSCs influenced by ADF and shed light on the cellular and molecular mechanisms by which ADF exerts beneficial actions on salivary gland restoration in SS.

Human papillomavirus (HPV) and Epstein-Barr virus (EBV) in Penile Cancer in Thailand.

Human papillomavirus (HPV) and Epstein-Barr virus (EBV) are important etiological factors for several cancers. This study aimed to determine the prevalence of HPV and EBV infection in penile cancer. Forty-three formalin-fixed paraffin-embedded penile cancer tissue samples were analyzed for the HPV-induced p16INK4A protein by immunohistochemistry and Epstein-Barr encoding region in situ hybridization. Demographic data and overall survival were analyzed. The median age of patients was 59 years, ranging from 23 to 91 years old. Most of the tumors (86%) were located at the tip of the penis. HPV infection was positive in 12/43 (27.9%) patients. EBV infection was observed in 2/43 (4.6%) of cases and there was no co-infection detected in this cohort. Patients who had p16INK4A overexpression had a trend toward longer survival compared to those without; the median survival time of 104.4 vs 89 months, the hazard ratio of 0.48 (95% CI: 0.16-1.42, p = 0.173). One-third of penile cancer patients were positive for HPV-induced p16INK4A expression and there was a trend toward better survival in HPV-positive patients. EBV infection was infrequent in penile cancer in Thailand.

Frailty and pre-frailty associated with long-term diminished physical performance and quality of life in breast cancer and hematopoietic cell transplant survivors.

Physical frailty as a sign of accelerated aging is not well characterized in breast cancer (BC) and hematopoietic cell transplant (HCT) survivors and its correlation with outcomes and quality of life (QOL) is not defined. We conducted a prospective study to determine the prevalence of frailty in adult BC and HCT survivors, examine its impact on QOL, and determine its association with p16INK4a, a molecular biomarker for biological aging. The study included 59 BC and 65 HCT survivors. Median age was 60 years (range 27-81), 68.5% were female and 49.2% were 18-59 vs. 51.8% ≥60 years old. A total of 71 (57.3%) were "fit" (frailty score 0) vs. 53 (42.7%) were pre-frailty/frail (frailty scores ≥1), and of the latter 17 (32.1%) were BC and 36 (67.9%) HCT patients. On multivariate analysis, patients >60 years were twice as likely to be frail (OR 2.04, 95% CI, 0.96-4.33; p=0.07), HCT were more likely to be frail compared to BC patients, and female HCT had 2.43 (95% CI, 0.92-6.40) and male HCT patients had 3.25 (95% CI, 1.37-7.72) times higher risk of frail; p=0.02. Frailty was associated with significant decline in QOL, measured by Medical Outcomes Study (MOS) Short Form 36 (SF-36) Physical Component Summary (PCS) and Mental Component Summary (MCS), and FACT (Functional Assessment of Cancer Therapy) scores. p16INK4a expression was higher in those who were frail, older than 60, and with higher expression in frail vs. fit patients who are 18-59 years. Our study highlights the high prevalence of frailty in survivors with detrimental effects on physical and overall wellbeing, and supports an association between frailty and the senescence marker p16INK4a.

MiR-96-5p expression is sufficient to induce and maintain the senescent cell fate in the absence of stress

Senescence is a cell fate driven by different types of stress that results in exit from the cell cycle and expression of an inflammatory senescence-associated secretory phenotype (SASP). Here, we demonstrate that stable overexpression of miR-96-5p was sufficient to induce cellular senescence in the absence of genotoxic stress, inducing expression of certain markers of early senescence including SASP factors while repressing markers of deep senescence including LINE-1 and type 1 interferons. Stable miR-96-5p overexpression led to genome-wide changes in heterochromatin followed by epigenetic activation of p16Ink4a, p21Cip1, and SASP expression, induction of a marker of DNA damage, and induction of a transcriptional signature similar to other senescent lung and endothelial cell types. Expression of miR-96-5p significantly increased following senescence induction in culture cells and with aging in tissues from naturally aged and Ercc1-/Δ progeroid mice. Mechanistically, miR-96-5p directly suppressed expression of SIN3B and SIN3 corepressor complex constituents KDM5A and MORF4L2, and siRNA-mediated knockdown of these transcriptional regulators recapitulated the senescent phenotype. In addition, pharmacologic inhibition of the SIN3 complex suppressed senescence and SASP markers. These results clearly demonstrate that a single microRNA is sufficient to drive early senescence in the absence of genotoxic stress through targeting epigenetic and transcriptional regulators, identifying novel targets for the development of senotherapeutics.

Potential Prognostic Role of Protein Kinase D Isoforms in Head and Neck Cancers.

Head and neck squamous cell carcinomas (HNSCC) are among the most common malignancies in men worldwide. Nevertheless, their clinical management is hampered by the limited availability of reliable predictive and prognostic biomarkers. Protein kinase D (PKD) isoforms contribute to major cellular processes. However, their potential role in HNSCC has not been studied systematically, which is the focus of this study. A total of 63 therapy-naive patients with squamous cell carcinoma were consecutively enrolled. Tissue microarray duplicate cores from each case were tested in situ for PKD1, PKD2, and PKD3 expression using immunohistochemistry, and the results were correlated with clinicopathological parameters. We found a high frequency of PKD1/PKD2 positive cases in oropharyngeal and PKD2 positive cases in laryngeal localizations. Only high PKD2 levels were statistically linked to elevated tumor grades, more advanced TNM (3-4) tumor stages, and p16INK4a expression, while elevated PKD3 levels were associated with favorable disease-specific survival. Both PKD2 and PKD3 have been proposed to promote tumor cell proliferation, migration/invasion, and angiogenesis. However, the role of PKD3 was elusive in some cancers. Our findings suggest that testing for PKD isotypes with immunohistochemistry may support the diagnostic estimation of tumor progression and prognosis in HNSCC with a potential therapeutic relevance.

Single-Cell Transcriptomic Analysis Identifies Senescent Osteocytes That Trigger Bone Destruction in Breast Cancer Metastasis.

Breast cancer bone metastases increase fracture risk and are a major cause of morbidity and mortality among women. Upon colonization by tumor cells, the bone microenvironment undergoes profound reprogramming to support cancer progression, which disrupts the balance between osteoclasts and osteoblasts and leads to bone lesions. A deeper understanding of the processes mediating this reprogramming could help develop interventions for treating patients with bone metastases. Here, we demonstrated that osteocytes (Ot) in established breast cancer bone metastasis develop premature senescence and a distinctive senescence-associated secretory phenotype (SASP) that favors bone destruction. Single-cell RNA sequencing identified Ots from mice with breast cancer bone metastasis enriched in senescence, SASP markers, and pro-osteoclastogenic genes. Multiplex in situ hybridization and artificial intelligence-assisted analysis depicted Ots with senescence-associated satellite distension, telomere dysfunction, and p16Ink4a expression in mice and patients with breast cancer bone metastasis. Breast cancer cells promoted Ot senescence and enhanced their osteoclastogenic potential in in vitro and ex vivo organ cultures. Clearance of senescent cells with senolytics suppressed bone resorption and preserved bone mass in mice with breast cancer bone metastasis. These results demonstrate that Ots undergo pathological reprogramming by breast cancer cells and identify Ot senescence as an initiating event triggering lytic bone disease in breast cancer metastases. Significance: Breast cancer cells remodel the bone microenvironment by promoting premature cellular senescence and SASP in osteocytes, which can be targeted with senolytics to alleviate bone loss induced by metastatic breast cancer. See related commentary by Frieling and Lynch, p. 3917.

Derivation of human primary prostate epithelial cell lines by differentially targeting the CDKN2A locus along with expression of hTERT

Prostate cancer (PCa) is the most common cancer diagnosed in men worldwide and was the second leading cause of cancer-related deaths in US males in 2022. Prostate cancer also represents the second highest cancer mortality disparity between non-Hispanic blacks and whites. However, there is a relatively small number of prostate normal and cancer cell lines compared to other cancers. To identify the molecular basis of PCa progression, it is important to have prostate epithelial cell (PrEC) lines as karyotypically normal as possible. Our lab recently developed a novel methodology for the rapid and efficient immortalization of normal human PrEC that combines simultaneous CRISPR-directed inactivation of CDKN2A exon 2 (which directs expression of p16INK4A and p14ARF) and ectopic expression of an hTERT transgene. To optimize this methodology to generate immortalized lines with minimal genetic alterations, we sought to target exon 1α of the CDKN2A locus so that p16INK4A expression is ablated while the exons encoding p14ARF remains unaltered. Here we describe the establishment of two cell lines: one with the above-mentioned p16INK4A only loss, and a second line targeting both products in the CDKN2A locus. We characterize the potential lineage origin of these new cell lines along with our previously obtained clones, revealing distinct gene expression signatures. Based on the analyses of protein markers and RNA expression signatures, these cell lines are most closely related to a subpopulation of basal prostatic cells. Given the simplicity of this one-step methodology and the fact that it uses only the minimal genetic alterations necessary for immortalization, it should also be suitable for the establishment of cell lines from primary prostate tumor samples, an urgent need given the limited number of available prostate cancer cell lines.

Expression of p16INK4a, FLOT2, and EGFR in oropharyngeal carcinoma, prognostic significance and correlation with clinicopathological characteristics.

Various factors can affect the survival of patients with oropharyngeal cancer. We assessed the expression of protein p16INK4a, Flotillin2, epidermal growth factor receptor, and other clinicopathological features and their prognostic value for this type of cancer. We gathered patient data on demographics, clinicopathological characteristics, treatment patterns, and outcomes. Histologically and by immunochemistry staining we determined expression of prognostic factors and molecular biomarkers. The primary endpoints were overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS). Survival was assessed using the Kaplan-Meier method and Cox regression model analyses of potential prognostic parameters. After a median follow-up of 78 months, the median OS was 41 months, with an event recorded in 77.8% of patients. Median DFS was 22 months, 37 patients (51.4%) had disease relapse. The DSS survival rate was 58.3% with a median survival of 68 months. In regards to molecular biomarkers previously mentioned, there was no statistical significance for survival categories. After conducting a multivariate analysis of significant variables, we found that only recurrence, vascular invasion, and surgical intervention remained as factors with independent effects on both OS and DFS. Recurrence and the N stage were identified as independent prognostic factors for DSS. Our analysis underscores the complexity of factors that collectively influence survival following the diagnosis of OPSCC. Several factors were found to be statistically significant. These factors included the type of surgical procedure, disease relapse, vascular invasion, lymphatic invasion, perineural invasion, advanced T stage of the disease, N stage of the disease, and smoking status. The significance of these factors may vary across different types of survival. This analysis did not find any significant impact on survival from the growth factors tested, namely epidermal growth factor receptor, Flotillin2, and p16INK4a, in the applied regression models.

Aging promotes accumulation of senescent and multiciliated cells in human endometrial epithelium.

What changes occur in the endometrium during aging, and do they impact fertility? Both the transcriptome and cellular composition of endometrial samples from women of advanced maternal age (AMA) are significantly different from that of samples from young women, suggesting specific changes in epithelial cells that may affect endometrial receptivity. Aging is associated with the accumulation of senescent cells in aging tissues. Reproductive aging is mostly attributed to the decline in ovarian reserve and oocyte quality, whereas the endometrium is a unique complex tissue that is monthly renewed under hormonal regulation. Several clinical studies have reported lower implantation and pregnancy rates in oocyte recipients of AMA during IVF. Molecular studies have indicated the presence of specific mutations within the epithelial cells of AMA endometrium, along with altered gene expression of bulk endometrial tissue. Endometrial transcriptome profiling was performed for 44 women undergoing HRT during the assessment of endometrial receptivity before IVF. Patients younger than 28 years were considered as the young maternal age (YMA) group (age 23-27 years) and women older than 45 years were considered as the AMA group (age 47-50 years). Endometrial biopsies were obtained on Day 5 of progesterone treatment and RNA was extracted. All endometrial samples were evaluated as being receptive based on the expression of 68 common endometrial receptivity markers. Endometrial samples from another 24 women classified into four age groups (YMA, intermediate age group 1 (IMA1, age 29-35), intermediate age group 2 (IMA2, age 36-44), and AMA) were obtained in the mid-secretory stage of a natural cycle (NC) and used for validation studies across the reproductive lifespan. A total of 24 HRT samples (12 YMA and 12 AMA) were subject to RNA sequencing (RNA-seq) and differential gene expression analysis, 20 samples (10 YMA and 10 AMA) were used for qPCR validation, and 24 NC samples (6 YMA, 6 IMA1, 6 IMA2 and 6AMA) were used for RNA-seq validation of AMA genes across the woman's reproductive lifespan. Immunohistochemistry (IHC) was used to confirm some expression changes at the protein level. Computational deconvolution using six endometrial cell type-specific transcriptomic profiles was conducted to compare the cellular composition between the groups. Comparisons between YMA and AMA samples identified a lower proportion of receptive endometria in the AMA group (P = 0.007). Gene expression profiling identified 491 differentially expressed age-sensitive genes (P adj < 0.05) that revealed the effects of age on endometrial epithelial growth and receptivity, likely contributing to decreased reproductive performance. Our results indicate that changes in the expression of the cellular senescence marker p16INK4a and genes associated with metabolism, inflammation, and hormone response are involved in endometrial aging. Importantly, we demonstrate that the proportion of multi-ciliated cells, as discovered based on RNA-seq data deconvolution and tissue IHC results, is affected by endometrial aging, and propose a putative onset of age-related changes. Furthermore, we propose that aging has an impact on the transcriptomic profile of endometrial tissue in the context of endometrial receptivity. The raw sequencing data reported in this article are deposited at the Gene Expression Omnibus under accession code GSE236128. This retrospective study identified changes in the endometrium of patients undergoing hormonal replacement and validated these changes using samples obtained during a NC. However, future studies must clarify the importance of these findings on the clinical outcomes of assisted reproduction. The findings reported in this study have important implications for devising future strategies aimed at improving fertility management in women of advanced reproductive age. This research was funded by the Estonian Research Council (grant no. PRG1076), Horizon 2020 innovation grant (ERIN, grant no. EU952516), Enterprise Estonia (grant no. EU48695), MSCA-RISE-2020 project TRENDO (grant no. 101008193), EU 874867 project HUTER, the Horizon Europe NESTOR grant (grant no. 101120075) of the European Commission, the EVA specialty program (grant no. KP111513) of the Maastricht University Medical Center (MUMC+), MICIU/AEI/10.13039/501100011033 and FEDER, EU projects Endo-Map (grant no. PID2021-12728OB-100), ROSY (grant no. CNS2022-135999), and the National Science Fund of Bulgaria (grant no. KII-06 H31/2). The authors declare no competing interests.