Predictive value of CDKN2A/p16INK4a expression in the malignant transformation of oral potentially malignant disorders: Systematic review and meta-analysis.

BACKGROUND: Management of oral potentially malignant disorders (OPMDs) is still challenging. Despite the diagnostic ascertainment by bioptic examination, this method is poorly informative of the prognosis and subsequent malignant transformation. Prognosis is based on histological findings by grading of dysplasia. Immunohistochemical expression of p16INK4a has been investigated in different studies, with controversial results. In this scenario, we systematically revised the current evidence about p16INK4a immunohistochemical expression and the risk of malignization of OPMDs. MATERIAL AND METHODS: After a proper set of keywords combination, 5 databases were accessed and screened to select eligible studies. The protocol was previously registered on PROSPERO (Protocol ID: CRD42022355931). Data were obtained directly from the primary studies as a measure to determine the relationship between CDKN2A/P16INK4a expression and the malignant transformation of OPMDs. Heterogeneity and publication bias were investigated by different tools, such as Cochran's Q test, Galbraith plot and Egger and Begg Mazumdar's rank tests. RESULTS: Meta-analysis revealed a twofold increased risk to malignant development (RR = 2.01, 95% CI = 1.36-2.96 - I2 = 0%). Subgroup analysis did not highlight any relevant heterogeneity. Galbraith plot showed that no individual study could be considered as an important outlier. CONCLUSION: Pooled analysis showed that p16INK4a assessment may arise adjunct tool to dysplasia grading, leading to an optimized determination of the potential progression to cancer of OPMDs. The p16INK4a overexpression analysis by immunohistochemistry techniques has a multitude of virtues that may facilitate its incorporation in the day-to-day prognostic study of OPMDs.

Relevance research between the expression of p16INK4a , Notch1, and hTERC genes: The development of HPV16-positive cervical cancer.

BACKGROUND: GLOBOCAN 2018 latest data show cervical cancer ranks fourth in morbidity and mortality among women. Many genes in cervical lesions differ in sensitivity and specificity. However, the diagnostic molecules for early cervical cancer are not very clear. This paper screens biomarkers for early molecular diagnosis of Mongolian patients with cervical cancer. METHODS: Immunohistochemical SP method was used to detect the expression of p16INK4a and Notch1 protein in paraffin sections of 226 Mongolian patients with HPV16-positive cervical lesions after pathological examination, and 100 of them were randomly selected by fluorescence in situ hybridization to detect hTERC gene. The HPV16-binding human cervical cancer SiHa cell line was used to silence the expression of HPV16 E6/E7 gene by RNA interference, and the expression of p16INK4a , Notch1, and hTERC genes and protein expression levels were detected by RT-PCR and Western blot. RESULTS: The positive expression rates of p16INK4a , Notch1, and hTERC genes in HPV16-positive cervical cancer, CIN-III, CIN-II, CIN-I, uterine leiomyoma, and chronic cervicitis were significantly different (P < .05); the positive expression rates of the three genes were also significantly different in the same type of cervical lesions (P < .05); RNA interference can effectively inhibit HPV16 E6/E7, p16INK4a and Notch1 gene expression, but has no effect on hTERC gene expression. CONCLUSION: The p16INK4a gene can be used as a biomarker for early screening of cervical cancer, and the hTERC gene can be used to confirm the clinical diagnosis of cervical cancer.

P16INK4a gene promoter methylation as a biomarker for the diagnosis of non-small cell lung cancer: An updated meta-analysis.

BACKGROUND: This meta-analysis was conducted to investigate the diagnostic performance of P16INK4a gene promoter methylation as a biomarker of non-small cell lung cancer (NSCLC). METHODS: Two reviewers independently searched the Web of Science, PubMed, Cochrane, Embase, China National Knowledge Infrastructure, and Chinese Biomedical Literature databases. Publications relevant to P16INK4a gene promoter methylation in serum or bronchoalveolar fluid/sputum were screened and included in this meta-analysis. Pooled diagnostic sensitivity, specificity, and symmetric receiver operating characteristic curve were calculated. RESULTS: Twenty-six publications with 1768 lung cancer cases and 1323 controls were included. The pooled sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio were 0.46 (95% confidence interval [CI] 0.43-0.48), 0.90 (95% CI 0.88-0.91), 6.33 (95% CI 3.89-10.30), 0.57 (95% CI 0.50-0.65) and 10.72 (95% CI 6.94-16.56), respectively, for P16INK4a gene promoter methylation as a biomarker for the diagnosis of NSCLC. The area under the symmetric receiver operating characteristic curve was 0.75 with a standard error of 0.004. No publication bias was detected via line regression test (t = 0.95; P = 0.35) and Begg's funnel plot. CONCLUSION: P16INK4a gene promoter methylation detection in serum or bronchoalveolar fluid/sputum may be a potential biomarker for NSCLC diagnosis; however, the sensitivity was relatively low, which is not suitable for NSCLC screening.

Involvement of Bmi-1 gene in the development of gastrointestinal stromal tumor by regulating p16Ink4A/p14ARF gene expressions: An in vivo and in vitro study.

OBJECTIVE: This study was conducted in order to explore the role that Bmi-1 plays during the development of a gastrointestinal stromal tumor (GIST) by regulation of the p16Ink4A and p14ARF expressions. METHODS: Eighty-six patients diagnosed with GIST were selected to take part in this experiment. The Bmi-1 protein expressions in GIST and adjacent normal tissues were detected using immunohistochemistry and further analyzed by using photodensitometry. To monitor and track the progression of the GIST, a 3-year follow-up was conducted for all affected patients. After cell transfection, the GIST cells were assigned into the control group (without transfection), the negative control (NC) group (transfected with Bmi-1-Scramble plasmid), and the Bmi-1 shRNA group (transfected with the pcDNA3.1-Bmi-1 shRNA plasmid). Protein and mRNA expressions collected from Bmi-1, p16lnk4A, P14ARF, cyclin D1, and CDK4 were measured using both the RT-qPCR and western blotting methods Cell senescence was assessed and obtained by using the ß-Galactosidase (ß-Gal) activity assay. The use of a Soft agar colony formation assay and CCK-8 assay were performed in order to detect the cell growth and subsequent proliferation. Cell invasion and migration were analyzed using the Transwell assay and scratch test. RESULTS: Bmi-1 in the GIST tissues was found to be significantly higher and the p16lnk4A and P14ARF expressions were lower than those in the adjacent normal tissues. Bmi-1 was negatively correlated with p16lnk4A and P14ARF expressions according to the correlation analysis. Bmi-1 expression was associated with the TNM stage, postoperative recurrence, metastasis, tumor size, and the 5-year survival rate. Area under ROC curve was calculated at 0.884, and sensitivity, specificity, and accuracy of Bmi-1 predicting the GIST were 67.44%, 97.67%, and 65.12%, respectively. Patients exhibiting a high Bmi-1 expression in the GIST tissues had lower survival rates than those with low Bmi-1 expression. In comparison with the control group, P14ARF, and p16lnk4A were up-regulated, while cyclinD 1 and CDK4 were down-regulated, cell senescence was promoted, and cell proliferation, invasion, and migration also showed some regression in the Bmi-1 shRNA group. CONCLUSIONS: These collection of data indicated that the down-regulated Bmi-1 might inhibit the proliferation, invasion, and migration of GIST cells and can be subsequently linked to the incidence and developing a prognosis of GIST.

Expressions of p16INK4a protein in cervical lesion tissues of Mongolian patients and their significances / 吉林大学学报(医学版)

Objective:To detect the expressions of p16INK4a protein in the cervical lesion tissues of the Mongolian patients, and to explore the relationship between its expression and the occurrence and development of cervical cancer in the Mongolian patients.Methods:A total of 100 cases of paraffin sections of cervical cancer, cervical intraepithelial neoplasia(CIN),chronic cervicitis and uterine leiomyoma were divided into 25 cases of cervical cancer, 35 cases of CIN, 20 cases of chronic cervicitis, and 20 cases of uterine leiomyoma groups. The expressions of p16INK4a protein in different cervical tissues were detected by immunohistochemical SP method.Results:The positive rates of p16INK4a protern in cervical cancer, CIN, chronic cervicitis and uterine leiomyoma tissnes were 100.0%, 74.3%, 25.0%,and 10.0%, respectively.The results of K-W H rank sum test for multiple sample comparisons showed that the positive expression rate of p16INK4a protein in cervical cancer tissue was significantly higher than those in CIN, chronic cervicitis and uterine leiomyoma tissues(P<0.05).Conclusion:p16INK4a protein can be used as a indicator to screen the Mongolian patients with early cervical cancer.

Expressions of p16INK4a gene and Bmi1 gene in human corneal endothelial cells of different ages / 中华实验眼科杂志

Background p16INK4a gene plays an important role during the aging and senility.So it was well known to be a leading gene associated with aging.Corneal endothelial cells(CECs) always get trapped in the G1 phase due to the lack of proliferative ability.Whether it is relative with cell senescence is unclear.Objective This study was to investigate the expression ofp16INK4a gene and Bmi1 gene in human CECs from different aged donors ex vivo.Methods The corneal rims,the residual of corneal tissue preserved in DX solution after penetrating keratoplasty,was used in the present study.Parameters were recorded for the donor,including the age,death to preservation interval and preservation to surgery interval.Corneal endothelium survival rate and endothelial cell density were evaluated by trypan blue-alizarin red dying immediately after penetrating keratoplasty.Routine haematoxylin and eosin staining was also performed to proof the normal structure of the cornea.Sections of corneas from different aged donors were classified into ＜30 years group,30-50 years group and ＞50 years group and were immunostained to assess the expressions of p16INK4aprotein,Bmi1 protein and Ki67 protein in CECs.Total RNA was extracted from independent corneal sample for the evaluation of p16INK4a mRNA,Bmi1 mRNA and Ki67 mRNA expression in CECs by quantitative real-time PCR(qRT-PCR).Results The endothelial cell density of each group was (3069 ±172),(2748±64),(2444 ±178)cells/mm2,respectively.Haematoxylin and eosin staining showed the normal structure of corneal epithelium,stroma and endothelium.qRT-PCR examination revealed an age-related increase in p16INK4a mRNA expression in the CECs(F =5.703,P =0.014) and a decrease in Bmi1 mRNA and Ki67 mRNA expression (F =3.950,P =0.042;F=548.500,P =0.000).The further comparison verified a significant elevation in the expression of p16INK4a mRNA in the CECs of the ＞50 years group compared with ＜30 years group and significant decline in Bmil mRNA and Ki67 mRNA the expression (P =0.006,0.013,0.000).Immunohistochemistry in situ confirmed the expression and nuclear localization of p16INK4a protein in CECs,and the expressing intensities of Bmi1 and Ki67 proteins in the elder donors were weaker than those of the younger donors.The immunofluorescence exhibited that the expressing intensity of p16INK4a protein in CECs of 58 years old donor was higher than that of 23 years old donor,showing a consistent result with that of qRT-PCR.Conclusions Expression of p16INK4a gene increases and that of Bmi1 gene decreases upon age.These results suggest that p16INK4a gene is associated with senescence of human CECs.

Effects of Exogenous p16ink4a Gene on Biological Behaviors of Human Lung Cancer Cells / 华中科技大学学报（医学）（英德文版）

The effects of exogenous p16ink4a gene on biological behaviors of human lung cancer cell line with homozygous deletion of p16ink4a gene were investigated. Exogenous p16ink4a gene was transfected by lipofectin into human lung cell line A549, in which p16ink4a gene was homozygously deleted. The expression of pl6ink4a mRNA and protein was detected by RT-PCR and immunocytochemistry, respectively. The changes in the behaviors of the transfected cell lines in vitro and in vivo were observed. In the transfected cell line A549, the exogenous p16ink4a gene could be stably expressed. The growth of A549 cells transfected with p16ink4a gene was obviously slowed down. Flow cytometry revealed that transfection of the exogenous p16ink4a gene resulted in A549 cell lines arrest in G1 phase of cell cycle. The tumorigenicity of these transfected cells in nude mice could be inhibited, and the tumor growth of nude mice was significantly suppressed. It was concluded that exogenous p16ink4a gene may be stably expressed in human lung cancer cell line A549. The expression of the introduced p16ink4a could block lung cancer cells to entry into S phase of cell cycle and inhibit tumor malignant growth both in vitro and in vivo.

Effects of wild-type INK4a gene on radiosensitivity of lung adenocarcinoma cell line A549 / 第三军医大学学报

Objective To assess the effects of transfection of plasmid pcDNA3.1-p16 containing the wild-type(wt) INK4a gene on the radiotherapy sensitivity of human lung adenocarcinoma cell line A549. Methods Using cationic liposome, the recombinant eukaryotic expression vectors pcDNA3.1-p16 were introduced into A549 cell line and named as A549-p16, in which the gene site INK4a was lost. By RT-PCR, immunocytochemistry and Western blotting after G418 selection, A549 cells stably expressing p16 were obtained. The parental cell and negative control cell with plasmid pcDNA3-LacZ were used as controls.The colony formation rate and 50% inhibition dose(ID_ 50) were measured and analyzed after radiation. Results As compared with the parental cell and negative control cell, re-expression of p16 in A549 induced the cell arrest at G_ 0/G_ 1. The growth rate and the colony formation rate decreased and the ID_ 50 decreased slightly in A549-p16. Conclusion The exogenous introduction of wtINK4a gene into lung adenocarcinoma cells A549 increased the radiosensitivity.