BACKGROUND: Glioblastoma, a highly aggressive form of brain cancer, poses significant challenges due to its resistance to therapy and high recurrence rates. This study aimed to investigate the expression and functional implications of CDKN2A, a key tumor suppressor gene, in glioblastoma cells, building upon the existing background of knowledge in this field.
METHODS: Quantitative reverse transcription PCR (qRT-PCR) analysis was performed to evaluate CDKN2A expression in U87 glioblastoma cells compared to normal human astrocytes (NHA). CDKN2A expression levels were manipulated using small interfering RNA (siRNA) and CDKN2A overexpression vector. Cell viability assays and carmustine sensitivity tests were conducted to assess the impact of CDKN2A modulation on glioblastoma cell viability and drug response. Sphere formation assays and western blot analysis were performed to investigate the role of CDKN2A in glioblastoma stem cell (GSC) self-renewal and pluripotency marker expression. Additionally, methylation-specific PCR (MSP) assays and demethylation treatment were employed to elucidate the mechanism of CDKN2A downregulation in U87 cells.
RESULTS: CDKN2A expression was significantly reduced in glioblastoma cells compared to NHA. CDKN2A overexpression resulted in decreased cell viability and enhanced sensitivity to carmustine treatment. CDKN2A inhibition promoted self-renewal capacity and increased pluripotency marker expression in U87 cells. CDKN2A upregulation led to elevated protein levels of p16INK4a, p14ARF, P53, and P21, which are involved in cell cycle regulation. CDKN2A downregulation in U87 cells was associated with high promoter methylation, which was reversed by treatment with a demethylating agent.
CONCLUSIONS: Our findings demonstrate that CDKN2A downregulation in glioblastoma cells is associated with decreased cell viability, enhanced drug resistance, increased self-renewal capacity, and altered expression of pluripotency markers. The observed CDKN2A expression changes are mediated by promoter methylation. These results highlight the potential role of CDKN2A as a therapeutic target and prognostic marker in glioblastoma.

BACKGROUND: Our aim was to assess the p16 expression in normal cervical epithelium and cervical lesions and how it correlated with HPV oncoprotein E7 and other etiological parameters of cervical cancer.
METHODS: For this purpose, we analyzed protein expression of p16 and E7 oncoprotein in total 20 normal cervical epithelium tissue (as control) and 62 cervical lesions. Next, the result was correlated with different clinico-pathological parameters.
RESULTS: Out of 62 cases of cervical lesions, we found around 75%-100% of the cervical lesion samples exhibited E7 nuclear protein expression, whereas around 33.33%-75% samples were p16 positive. On the other hand, p16 expression showed strong association with E7 oncoprotein and other clinico-pathological parameters (like high parity, early age of sextual debut) in the same set of samples of our study.
CONCLUSIONS: We concluded that overexpression of p16 is very practical and can be readily implemented in most diagnostic pathology laboratories.

BACKGROUND: Patrinia villosa (Juss.) (PV) is the drug of choice in traditional Chinese medicine for the treatment of colorectal cancer (CRC) and has achieved reliable efficacy in clinic. Villosol is the active ingredient in PV. However, the molecular mechanism by which Villosol reverses chemoresistance in CRC remains unclear.
OBJECTIVE: Analysis of the molecular mechanism by which Villosol, the active ingredient of PV, reverses CRC/5-FU resistance through modulation of the CDKN2A gene was validated by network pharmacology techniques and experiments.
METHODS: We identified CDKN2A as a gene associated with 5-FU resistance through gene chip analysis. Next, we conducted a series of functional analyses in cell lines, animal samples, and xenograft models to investigate the role, clinical significance, and abnormal regulatory mechanisms of CDKN2A in 5-FU resistance in CRC. In addition, we screened and obtained a raw ingredient called Villosol, which targets CDKN2A, and investigated its pharmacological effects.
RESULTS: Analysis of CRC cells and animal samples showed that the upregulation of CDKN2A expression was strongly associated with 5-FU resistance. CRC cells overexpressing CDKN2A showed reduced sensitivity to 5-FU and enhanced tumor biology in vitro. Inhibition of aberrant activation of CDKN2A enhances the expression of TP53. Mechanistically, overexpression of CDKN2A activates the PI3K/Akt pathway and induces resistance to 5-FU. Villosol inhibited CDKN2A, and CRC/5-FU cells regained sensitivity to 5-FU. Villosol effectively reverses 5-FU resistance through the CDKN2A-TP53-PI3K/Akt axis.
CONCLUSIONS: Changes in CDKN2A gene expression can be used to predict the response of CRC patients to 5-FU therapy. Additionally, inhibiting CDKN2A activation with Villosol may present a new approach to overcoming 5-FU resistance in clinical settings.

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease with clinical and pathological heterogeneity. Recent studies have identified cuproptosis as a novel cell death mechanism. However, the role of cuproptosis-related genes in the pathogenesis of IPF is still unclear. Two IPF datasets of the Gene Expression Omnibus database were studied. Mann-Whitney U test, correlation analysis, functional enrichment analyses, single-sample gene set enrichment analysis, CIBERSORT, unsupervised clustering, weighted gene co-expression network analysis, and receiver operating characteristic curve analysis were used to conduct our research. The dysregulated cuproptosis-related genes and immune responses were identified between IPF patients and controls. Two cuproptosis-related molecular clusters were established in IPF, the high immune score group (C1) and the low immune score group (C2). Significant heterogeneity in immunity between clusters was revealed by functional analyses results. The module genes with the strongest correlation to the 2 clusters were identified by weighted gene co-expression network analysis results. Seven hub genes were found using the Cytoscape software. Ultimately, 2 validated diagnostic biomarkers of IPF, CDKN2A and NEDD4, were obtained. Subsequently, the results were validated in GSE47460. Our investigation illustrates that CDKN2A and NEDD4 may be valid biomarkers that were useful for IPF diagnosis and copper-related clustering.

Recently, there has been a great deal interest in cuproptosis, a form of programmed cell death that is mediated by copper. The specific mechanism through which cuproptosis-related genes impact the development of colorectal cancer (CRC) remains unknown.
Here, we combined bulk RNA-seq with scRNA-seq to investigate the CRGs functions within CRC. A number of 61 cuproptosis-related genes were chosen for further investigation. Nine prognostic CRGs were identified by Lasso-Cox. The RiskScore was created and the patients have been separated into two different groups, low- and high-RiskScore group. The CIBERSORT, ESTIMATE, MCP-counter, TIDE, and IPS have been employed to score the TME, and GSVA and GSEA were utilized to evaluate the pathway within the both groups. Further, we used cell communication analysis to explore the tumor microenvironment remodeling mechanisms of the COX17 and DLAT based on scRNA-seq. Finally, we used IHC and qPCR to validate the expression of COX17 and DLAT.
AOC3, CCS, CDKN2A, COX11, COX17, COX19, DLD, DLAT, and PDHB have been recognized as prognostic CRGs in CRC. The high-risk group exhibited the worst prognosis, an immune-deficient phenotype, and were more resistant to ICB treatment. Further, scRNA-seq analysis revealed that elevated expression of COX17 in CD4-CXCL13Tfh could contribute to the immune evasion while DLAT had the opposite effect, reversing T cell exhaustion and inducing pyroptosis to boost CD8-GZMKT infiltration.
The current investigation has developed a prognostic framework utilizing cuproptosis-related genes that is highly effective in predicting prognosis, TME type, and response to immunotherapy in CRC patients. Furthermore, our study reveals a novel finding that elevated levels of COX17 expression within CD4-CXCL13 T cells in CRC mediates T cell exhaustion and Treg infiltration, while DLAT has been found to facilitate the anti-tumor immunity activation through the T cell exhaustion reversal and the induction of pyroptosis.

The objective of this study was to evaluate the role of p16 in histologic characteristics and transition of Pleomorphic Adenoma (PA) to Carcinoma ex-PA (CxPA). So, 60 PA and 4 CxPA were histologic reviewed based on microscopic characteristics proposed by Hellquist, Triantafyllou and Dulguerov (PA) and Morais, Antony and Toluie (CxPA). Immunostaining for p16 was associated in different parenchyma and stroma of both tumors and Fisher\'s/chi-square tests and Mann-Whitney test were performed (SPSS v20.0, p<0.05). In PA the periductal cells were predominantly p16- and that ductal and myoepithelial cells showed a significant increase in p16+ cells (p<0.001). In CxPA, none of the cases showed p16+ in periductal cells, most parotid cases showed p16+ in ductal cells, and one case of parotid and the submandibular case showed mild immunostaining for myoepithelial cells. There was a small reduction in p16+ in CxPA compared to PA (p=0.537), but in both tumors there was less p16+ cells in solid stroma than other (p<0.001). The p16+ cases of PA had a higher capsular thickness (p=0.047). So, the loss of p16 immunostaining does not seem to be associated with the transition from PA to CxPA, but in both tumors the loss of p16+ cells are related to microscopic aggressiveness.

Tongue squamous cell carcinoma (TSCC) has a poor prognosis and destructive characteristics. Reliable biomarkers are urgently required to predict disease outcomes and to guide TSCC treatment. This study aimed to develop a multigene signature and prognostic nomogram that can accurately predict the prognosis of patients with TSCC. We screened differentially expressed genes associated with TSCC using The Cancer Genome Atlas dataset. Based on this, we developed a new multi-mRNA gene signature using univariate Cox regression, Least Absolute Shrinkage and Selection Operator regression, and multivariate Cox regression. We used the concordance index to evaluate the accuracy of this new multigene model. Moreover, we performed receiver operating characteristic and Kaplan-Meier survival analyses to assess the predictive ability of the new multigene model. In addition, we created a prognostic nomogram incorporating clinical and pathological characteristics, with the aim of enhancing the adaptability of this model in practical clinical settings. We successfully developed a new prognostic model based on the expression levels of these 3 mRNAs that can be used to predict the prognosis of patients with TSCC. This prediction model includes 3 genes: KRT33B, CDKN2A, and CA9. In the validation set, the concordance index of this model was 0.851, and the area under the curve was 0.778 and 0.821 in the training and validation sets, respectively. Kaplan-Meier survival analysis showed that regardless of whether it was in the training or validation set, the prognosis of high-risk patients was significantly worse than that of low-risk patients (P < .001). Multivariate Cox regression analysis revealed that this model was an independent prognostic factor for patients with TSCC (P < .001). Our study suggests that this 3-gene signature model has a high level of accuracy and predictive ability, is closely related to the overall survival rate of patients with TSCC, and can independently predict the prognosis of TSCC patients with high accuracy and predictive ability.

Familial melanoma is defined as melanoma occurring in two or more first-degree relatives by the WHO. Germline mutations are isolated in a subset of them. It is well known that CDKN2A is the most frequently mutated high-risk gene in familial melanoma, however, the prognosis it confers to patients who carry its mutations is still controversial. This review aims to assess whether germline mutations imply a worse prognosis in patients with familial melanoma. A systematic review and meta-analysis were conducted by searching the electronic databases PubMed/MEDLINE, EMBASE, and Cochrane Library. Data from 3 independent populations were eventually included in the meta-analysis, involving 291 cases and 57 416 controls. The results of this systematic review and meta-analysis suggest that there is a tendency for patients with germline mutations in the CDKN2A gene to have a worse overall survival (HR = 1.30, 95% CI = 0.99-1.69, P  = 0.05) and melanoma-specific survival (HR = 1.5, 95% CI = 0.97-2.31, P  = 0.07). Carrier patients would not only have more incidence of melanoma and a higher risk of a second melanoma, but they also seem to have a worse prognosis. The inclusion of gene panel testing in clinical practice and the collaboration within consortia are needed to provide further evidence on the prognosis of these patients.

CDKN2A encodes the tumor suppressors p16 and p14ARF and is the most common homozygously deleted gene in all human cancers; tumors frequently codelete the nearby gene MTAP, creating a dependency on PRMT5. In this issue of Cancer Discovery, Engstrom and colleagues report an MTA-cooperative PRMT5 methyltransferase inhibitor MRTX1719 that selectively kills CDKN2A/MTAP-codeleted cancers and demonstrates early efficacy in clinical trials for solid tumors harboring the CDKN2A/MTAP codeletion. See related article by Engstrom et al., p. 2412 (1).

Before the discovery of cuproptosis, copper-loaded nanoparticle is a wildly applied strategy for enhancing the tumor-cell-killing effect of chemotherapy. Although copper(ii)-related researches are wide, details of cuproptosis-related bioprocess in pan-cancer are not clear yet now, especially for prognosis and drug sensitivity prediction yet now.
In this study, VOSviewer is used for the literature review, and R4.2.0 is used for data analysis. Public data are collected from TCGA and GEO, local breast cancer cohort is collected to verify the expression level of CDKN2A.
7036 published articles exhibited a time-dependent linear relationship (R=0.9781, p<0.0001), and breast cancer (33.4%) is the most researched topic. Cuproptosis-related-genes (CRGs)-based unsupervised clustering divides pan-cancer subgroups into four groups (CRG subgroup) with differences in prognosis and tumor immunity. 44 tumor-driver-genes (TDGs)-based prediction model of drug sensitivity and prognosis is constructed by artificial intelligence (AI). Based on TDGs and clinical features, a nomogram is (C- index: 0.7, p= 6.958e- 12) constructed to predict the prognosis of breast cancer. Importance analysis identifies CDKN2A has a pivotal role in AI modeling, whose higher expression indicates worse prognosis in breast cancer. Furthermore, inhibition of CDKN2A down-regulates decreases Snail1, Twist1, Zeb1, vimentin and MMP9, while E-cadherin is increased. Besides, inhibition of CDKN2A also decreases the expression of MEGEA4, phosphorylated STAT3, PD-L1, and caspase3, while cleaved-caspase3 is increased. Finally, we find down-regulation of CDKN2A or MAGEA inhibits cell migration and wound healing, respectively.
AI identified CRG subgroups in pan-cancer based on CRGs-related TDGs, and 44-gene-based AI modeling is a novel tool to identify chemotherapy sensitivity in breast cancer, in which CDKN2A/MAGEA4 pathway played the most important role.