Correlation between p14(ARF)/p16(INK4A) expression and HPV infection in uterine cervical cancer

The CDKN2A locus on human chromosome 9p21 encodes two tumor suppressors, p14(ARF) and p16(INK4A), which enhance the growth-suppressive functions of the retinoblastoma (Rb) and the p53 proteins, respectively. Conversely, the E6 and E7 oncoproteins of the high-risk human papillomaviruses (HPVs) causally associated with carcinogenesis of the uterine cervix contributes to tumor development by inactivating p53 and Rb. Nevertheless, a correlation between expression of p14(ARF)/p16(INK4A) and HPV infection in uterine cervix is less clear. To clarify this, we examined 25 cervical cancers and 11 normal uterine cervixes. HPV was detected in 21 of 25 cervical cancers (84%) and their subtype was determined by PCR-RFLP. Quantitative real-time RT-PCR assays showed overexpression of p14(ARF) mRNA in all 21 HPV-positive cases (100%). p16(INK4A) mRNA was overexpressed in 17 cases of the HPV-positive cases (81%). In four HPV-negative cancers, reduced expression of p14(ARF) mRNA was detected in two cases (50%) and reduced p16(INK4A) mRNA in three cases (75%). Our data indicate that the overexpression of p14(ARF) and p16(INK4A) strongly associates with HPV-positive cervical cancers and that reduced expression of p14(ARF) and p16(INK4A) correlates with HPV-negative cervical cancers. These findings may indicate that impaired p14(ARF) and p16(INK4A) mRNA expression contribute to tumor development in HPV-negative cervical cancers by failure to support p53 and Rb instead of their inactivation by HPV E6 and E7.     

p16INK4a and laminin-5gamma2 chain expression during the progression of cervical neoplasia

p16INK4a, laminin-5gamma2 chain, and PCNA were investigated to compare the expression levels in relation to histological diagnosis and time for progression. The material consisted of 37 normal cervical tissues, 35 with different grades of CIN, and 11 invasive cervical cancers. Our results showed a reduction of basement membrane staining for laminin-5gamma2 chain from 78.4% in normal squamous epithelium to 27.8% in CIN3 (p < 0.001). The intracytoplasmic staining for laminin-5gamma2 chain increases with severity of lesion. The same trend was observed with p16INK4a and PCNA expression (p < 0.001). Co-expression of p16INK4a and PCNA was seen in 85.7% of samples. Cases that were laminin-5gamma2 chain BM - /p16INK4a+/PCNA+ have the shortest interval time (average: 46.8+/-36.3 months) for progression, while cases with laminin-5gamma2 chain BM + /p16INK4a-/PCNAPCNA--have the longest time interval (average: 110.2+/-52.7 months) (p < 0.05). Thus co-expression of p16INK4a, laminin-5gamma2 chain and PCNA may be valuable for the prediction progression of cervical neoplasia.     

p14ARF protein expression is a predictor of both relapse and survival in squamous cell carcinoma of the anterior tongue.

PURPOSE: The INK4A-ARF locus at chromosome 9p21 is frequently altered in head and neck squamous cell carcinoma (SCC) and encodes two distinct tumor suppressors, p16(INK4A) and p14(ARF). This study addressed the role of p14(ARF) as a potential prognostic marker in this disease. EXPERIMENTAL DESIGN: p14(ARF) protein expression was assessed by immunohistochemistry in a cohort of 140 patients with SCC of the anterior tongue. Using univariate and multivariate Cox's proportional hazards models, the outcomes examined were time to disease recurrence or death, with or without clinicopathologic covariates, including nodal status, disease stage, treatment status, Ki-67 staining, and molecular markers with known functional or genetic relationships with p14(ARF) (p16(INK4A), p53, pRb, p21(WAF1/CIP1), E2F-1). RESULTS: On multivariate analysis, p14(ARF) positivity (nucleolar p14(ARF) staining and/or nuclear p14(ARF) staining in >/=30% of tumor cells) was an independent predictor of improved disease-free survival (DFS; P = 0.002) and overall survival (OS; P = 0.002). This was further enhanced when p14(ARF) positivity was cosegregated with positive (>/=1%) p16(INK4A) staining (DFS, P < 0.001; OS, P < 0.001). Patients whose cancers were p14(ARF) negative and p53 positive (>50%) had the poorest outcome (DFS, P < 0.001; OS, P < 0.001) of any patient subgroup analyzed. CONCLUSIONS: These data show that in patients with SCC of the tongue, combined nuclear and nucleolar expression of p14(ARF) protein predicts for improved DFS and OS independent of established prognostic markers.     

Genomic instability, mutations and expression analysis of the tumour suppressor genes p14(ARF), p15(INK4b), p16(INK4a) and p53 in actinic keratosis

Actinic keratosis (AK) is a well-established pre-cancerous skin lesion that has the potential to progress to squamous cell carcinoma (SCC). We investigated the involvement of the CDKN2A, CDKN2B and p53 genes in AK and in the progression of AK to SCC. Mutational analysis on exons 1a, 1b and 2 of the CDKN2A locus and exon 1 of the CDKN2B locus as well as allelic imbalance was performed in 26 AK specimens. Expression levels of the genes p14(ARF), p15(INK4b), p16(INK4a) and p53 were examined in 16 AKs and 12 SCCs by real-time RT-PCR. A previously described polymorphism of p16(INK4a) (Ala148Thr) was detected at an allelic frequency of 12%. Six samples carried novel mutations at codon 71 of the CDKN2A locus and one sample presented an additional mutation at codon 65. Two AK samples carried a not-previously described non-UV type missense mutation at codon 184 (Val184Glu) of exon 1b in the p14(ARF) gene. Regarding the CDKN2B locus a new mutation at codon 50 (Ala50Thr) and another at codon 24 (Arg24Arg), were detected. Microsatellite instability (MSI) was found in 15% of AKs in at least one marker, indicating that genetic instability has some implication in the development of AK. Down-regulation of p16(INK4a) and p53 mRNA levels was noted in SCC compared to AK. TSGs expression levels in sun-exposed morphologically normal-appearing skin, suggests that abnormal growth stimuli might exist in these tissues as well. Furthermore, we suggest a possible role of p15(INK4b), independently from the intracellular pathway mediated by p16(INK4a), and of p14(ARF) in AK development, as well as in the progression of AK to SCC. The deregulation of the expression profiles of the CDKN2A, CDKN2B and p53 genes may, independently of mutations and LOH at 9p21, play a significant role in AK and progression of AK to SCC.     

p16^INK4a和p14^ARF蛋白在宫颈癌和肺癌中的差异表达

[目的]研究宫颈癌和肺癌中p16INK4a和p14ARF蛋白表达水平的差异及意义。[方法]应用免疫组化方法检测50例宫颈癌和127例肺癌组织中p16INK4a和p14ARF蛋白表达。[结果]50例宫颈癌中,p16INK4a和p14ARF蛋白全部阳性表达;127例肺癌中,p16INK4a和p14ARF蛋白阳性表达率分别为61.42%和30.79%;宫颈癌和肺癌中p16INK4a和p14ARF蛋白表达差异均有显著性（P〈0.01）。[结论]p16INK4a和p14ARF蛋白在宫颈癌中过表达,而在肺癌中缺失表达。提示p16INK4a和p14ARF蛋白在宫颈癌和肺癌的发生发展中所起的作用和作用机制可能不同。     

乳头瘤病毒L1衣壳蛋白及p16INK4A基因在子宫颈病变中的表达及其相关性

 目的　研究乳头瘤病毒衣壳蛋白（HPVL1）及p16INK4A基因在子宫颈病变患者中的表达与相关性。方法　采用免疫组织化学Max-Vision法检测210例HPV阳性液基细胞学标本及组织中HPV L1蛋白及p16INK4A的表达。结果　在各级液基细胞学标本中,HPVL1蛋白阳性率各组比较差异有统计学意义（χ2＝70.50、P＜0.005）,其中低度鳞状上皮内病变（LSIL）组最高[68 %（34／50）];p16INK4A表达阳性率随着病变级别的增高逐渐增高（13 %、28 %、52 %、100 %、100 %）,在子宫颈癌（SCC）组最高[100 %（30／30）]。HPVL1+p16INK4A -率在LSIL组中最高[32 %（16／50）];HPVL1-p16INK4A +率在SCC组最高[100 %（30／30）]。在各级别病理组织中,HPVL1蛋白表达阳性率不同,差异有统计学意义（χ2＝54.37、P＜0.005）,其中,CINⅠ级中最高[60.4 %（32／53）];p16INK4A表达阳性率随着病变级别的增高逐渐增高,在子宫颈癌组最高[100 %（28／28）]。HPVL1+p16-率在CINⅠ级中最高[45.3 %（24／53）];HPVL1-p16+率在子宫颈癌中最高[100 %（28／28）]。结论　HPVL1蛋白与p16INK4A联合检测可以区分不同的子宫颈病变,将有潜在发展与有自愈可能的病例分开,避免漏诊与过度治疗。     

The study of the combination detection of HPV-DNA and p16INK4a in cervical lesions

The objective of this study is to detect the infection of human papillomavirus (HPV) and the expression of p16(INK4a) in cervical lesions and to investigate the interaction between hrHPV and p16(INK4a) for cervical lesions and its diagnostic efficiency. hrHPV-DNA was detected by the hybrid capture II (HC-II) system. Immunochemical method was used to detect the expression of p16(INK4a), and histopathologic test was performed to identify cervical lesions. χ(2) test and Spearman's rank correlation were used for statistical analysis. Additive effects model was used to analyze the interaction. The diagnostic sensitivity, specificity, positive predictive values, negative predictive values, accuracy, and the area under the receiver operating characteristic curve were calculated with SPSS 13.0. hrHPV and p16(INK4a) positive rate increased (P < 0.05) with histopathologic diagnosis increasing. The positive rates of hrHPV and p16(INK4a) in negative or chronic inflammation were statistically lower than that in cervical intraepithelial neoplasia (CIN)1, CIN2, CIN3, and squamous-cell carcinoma (SCC) (P < 0.05), respectively. There was a positive interaction between hrHPV and p16(INK4a), relative excess risk of interaction (RERI) was 52.49, attributable proportions of interaction (API) were 72.34%, and the synergy index (S) was 3.75. The specificity and AUC of combining hrHPV with p16(INK4a) were statistically higher than hrHPV or p16(INK4a) alone (P < 0.05). hrHPV and p16(INK4a) are useful markers for the early diagnosis of cervical lesions. A positive interaction between hrHPV and p16(INK4a) is seen. The combination of hrHPV and p16(INK4a) has a higher diagnostic accuracy than hrHPV or p16(INK4a) alone in diagnosis of cervical lesions.     

Alterations of the p16INK4a/p14ARF pathway in clear cell sarcoma

Clear cell sarcoma (CCS) is a very rare soft tissue sarcoma with a poor prognosis. It has become apparent through immunohistochemical, ultrastructural, and microarray analyses that CCS is a soft tissue melanocytic neoplasm. Alterations in the p16INK4a/p14ARF gene are common in malignant melanoma, which is the prototypical melanocytic neoplasm. In the present study, we performed a clinicopathologic analysis and investigated p16 and cyclin D1 expression by immunohistochemistry in 14 cases. Furthermore, we investigated genetic changes of various tumor suppressor genes and an oncogene, including p16INK4a/p14ARF, p53, beta-catenin, and APC, in 11 cases. The 5-year overall survival rate in all the patients was 33.3%. A high mitotic rate was a significant adverse prognostic factor (P = 0.004). Decreased expression of p16 was observed in 4 (28.6%) of 14 cases. Overexpression of cyclin D1 was observed in 9 cases (64.3%). SSCP analysis followed by DNA direct sequencing revealed point mutations of the p16INK4a gene in 2 of 11 cases (18.2%). In addition, one case with the p14ARF mutation and 2 cases with the p53 mutation were observed. None of the cases harbored mutation of the beta-catenin or APC gene. Homozygous deletion of the p16INK4a/p14ARF gene was detected in one case. Methylation-specific PCR did not reveal hypermethylation of the p16INK4a/p14ARF promoter region in any of the cases. Three cases harbored genetic alterations of the p16INK4a/p14ARF gene (27.3%). All tumors with genetic alterations of the p16INK4a/p14ARF or p53 gene showed a high mitotic rate or tumor necrosis. These alterations were considered to be influential in the poor prognosis of CCS patients.     

Mechanisms of inactivation of p14ARF, p15INK4b, and p16INK4a genes in human esophageal squamous cell carcinoma.

The 9p21 gene cluster, harboring growth suppressive genes p14ARF, p15INK4b, and p16INK4a, is one of the major aberration hotspots in human cancers. It was shown that p14ARF and p16INK4a play active roles in the p53 and Rb tumor suppressive pathways, respectively, and p15INK4b is a mediator of the extracellular growth inhibition signals. To elucidate specific targets and aberrations affecting this subchromosomal region, we constructed a detailed alteration map of the 9p21 gene cluster by analyzing homozygous deletion, hypermethylation, and mutation of the p14ARF, p15INK4b, and p16INK4a genes individually in 40 esophageal squamous cell carcinomas (ESCCs) and compared the genetic alterations with mRNA expression in 18 of these samples. We detected aberrant promoter methylation of the p16INK4a gene in 16 (40%), of p14ARF in 6 (15%), and of p15INK4b in 5 (12.5%) tumor samples. Most p16INK4a methylations were exclusive, whereas all but one of the p14ARF/p15INK4b methylations were accompanied by concomitant p16INK4a methylation. We detected homozygous deletion of p16INK4a in 7 (17.5%), of p14ARF-E1beta in 13 (33%), and of p15INK4b in 16 (40%) tumor samples. Most deletions occurred exclusively on the E1beta-p15INK4b loci. Two samples contained p14ARF deletion but with p16INK4a and p15INK4b intact. No mutation was detected in the p14ARF and p16INK4a genes. Comparative RT-PCR showed good concordance between suppressed mRNA expression and genetic alteration for p15INK4b and p16INK4a genes in the 18 frozen samples, whereas 5 of the 13 cases with suppressed p14ARF mRNA expression contained no detectable E1beta alteration but aberrations in the p16INK4a locus. Our results show that in human ESCCs, p14ARF is a primary target of homozygous deletion along with p15INK4b, whereas p16INK4a is the hotspot of hypermethylation of the 9p21 gene cluster. The frequent inactivation of the p14ARF and p16INK4a genes may be an important mechanism for the dysfunction of both the Rb and p53 growth regulation pathways during ESCC development.     

Ratio of expression of p16INK4a to p14ARF correlates with the progression of non-small cell lung cancer.

The CDKN2 gene is located on the short arm of chromosome 9p and encodes two unrelated proteins, p16(INK4a) and p14(ARF), through the use of independent first exons and shared exons 2 and 3. p16(INK4a) is a cyclin-dependent kinase inhibitor, whereas p14(ARF) regulates the cell cycle through a p53 and MDM2-dependent pathway. We have examined the expression of p16(INK4a) and p14(ARF) using competitive RT-PCR in 60 non-small cell lung cancers (NSCLCs) and matching normal lung tissues. The intensities of bands for p16(INK4a) and p14(ARF) were nearly equal or the intensity of the p16(INK4a) band slightly exceeded that of p14(ARF) in the normal lung tissues (n = 60). In 38 tumors the intensity of the p16(INK4a) band was similar to or slightly weaker than that of p14(ARF). In 6 tumors the intensity of the p16(INK4a) band was weaker than that of p14(ARF). In 15 tumors the intensity of the p14(ARF) band was very strong and the p16(INK4a) band was barely visible. In only one tumor was the intensity of the p16(INK4a) band very strong, while the band of p14(ARF) was barely visible. The ratio of the intensity of p16(INK4a) to p14(ARF) had an interesting correlation with the tumor's clinicopathological characteristics. The p stage II - IV tumors had significantly lower p16(INK4a) to p14(ARF) ratios than the p stage I tumors (P = 0.036). The T2 - 4 tumors had significantly lower p16(INK4a) to p14(ARF) ratios than the T1 tumors (P = 0.005). The N1 - 3 tumors had significantly lower p16(INK4a) to p14(ARF) ratios than the N0 tumors (P = 0.014). Our results suggest that the ratio of expression of p16(INK4a) to p14(ARF) tends to decrease during the progression of NSCLC.     

The prognostic significance of p16(INK4a)/p14(ARF) locus deletion and MDM-2 protein expression in adult acute myelogenous leukemia

BACKGROUND: The p16(INK4a) locus encodes two distinct proteins, p16(INK4a) and p14(ARF). Although p16(INK4a) and p15(INK4b) are involved in the phosphorylation of the retinoblastoma (Rb) protein, p14(ARF) interacts with the MDM-2 oncoprotein antagonizing its function as a suppressor of p53. The role of deletions of p16(INK4a)/p14(ARF) and p15(INK4b) and expressions of MDM-2 in myeloid leukemias and its influence on prognosis remain unclear. METHODS: The authors analyzed deletions of p16(INK4)/p14(ARF) and p15(INK4b) in 74 adults with acute myeloid leukemia (AML) by Southern blotting. Western blotting was used to determine Rb protein phosphorylation in patients with deletions of p16(INK4)/p14(ARF) and p15(INK4b). Then, they analyzed the levels of MDM-2 protein expression and correlated it with prognosis in an expanded population of 79 adults with AML by immunoblot analysis and solid-phase radioimmunoassay. RESULTS: Deletions of p16(INK4a)/p14(ARF) and/or p15(INK4b) occurred in 4 of 74 patients (5%) (hemizygous in 3, homozygous in 1 patient). Although the complete remission (CR) rate was similar (79% vs. 50%; P = 0.187), CR duration (10 vs. 46 weeks; P < 0.001), event free survival rate (EFS; 6 vs. 85 weeks; P < 0.004) and overall survival rate (11 vs. 86 weeks; P = 0.001) were significantly shorter in patients with deletions of p16(INK4a)/p14(ARF) and/or p15(INK4b). Thirty-seven (47%) of 79 patients studied for MDM-2 showed increased MDM-2 expression. These patients had a significantly shorter EFS rate (50 vs. 64 weeks; P = 0.023) and a trend for shorter CR duration (24 vs. 53 weeks; P = 0.07). Overall survival rate was not significantly different (50 vs. 84 weeks; P = 0.136). CONCLUSIONS: The authors concluded that 1) deletions of p16(INK4a)/p14(ARF) and/or p15(INK4b) occur with low incidence in patients with AML; 2) patients with deletions of p16(INK4a)/p14(ARF) and/or p15(INK4b) have a significantly shorter CR duration, EFS rate, and overall survival rate than do patients without deletions; (3) overexpression of MDM-2 is common in AML and is associated with shorter CR duration and EFS rate. Mechanisms other than p14(ARF) deletion are responsible for MDM-2 overexpression, and this overexpression may play a role in the biology of the disease.     

CIN和子宫颈鳞癌的HPV16/18感染与p53、MDM2蛋白表达的关系

目的研究子宫颈鳞癌及C IN的HPV感染、p53蛋白和M DM 2蛋白的表达及三者之间的相互关系。方法选取子宫颈鳞癌61例、C IN 47例、正常子宫颈组织54例,分别采用原位杂交技术检测HPV 16/18感染,用免疫组化技术S-P法检测p53蛋白和M DM 2蛋白。结果HPV 16/18感染率鳞癌组为62.3%(38/61),C IN组为70.2%(33/47),对照组为16.7%(9/54)。C IN组和鳞癌组的HPV 16/18的感染率均显著高于对照组(P值均<0.05)。而C IN组与鳞癌组的HPV 16/18感染率差异无显著性(P>0.05)。C IN组、鳞癌组、对照组的p53阳性率分别为19.1%(9/47)、26.2%(16/61)、3.7%(2/54)。C IN组、鳞癌组、对照组的M DM 2阳性率分别为14.9%(7/47)、26.2%(16/61)、7.4%(4/54)。C IN组和鳞癌组的p53阳性率均显著高于对照组(P值均<0.05),C IN组与鳞癌组比较差异无显著性(P>0.05)。M DM 2阳性率鳞癌组显著高于对照组(P<0.05),而在C IN组和鳞癌组之间、C IN组和对照组之间差异均无显著性(P值均>0.05)。在本实验各组中,p53与M DM 2之间的阳性率均无统计学相关(P值均>0.05)。p53阳性率和HPV 16/18感染之间差异无显著性(P值均>0.05),而M DM 2的阳性率与HPV 16/18感染仅在子宫颈鳞癌组呈正相关(P<0.05)。结论C IN及子宫颈鳞癌与HPV 16/18感染关系密切;p53和M DM 2均参与子宫颈癌及癌前病变的发生,但p53的突变、M DM 2的扩增和过表达均不占主导地位。     

Progression of actinic keratosis to squamous cell carcinoma of the skin correlates with deletion of the 9p21 region encoding the p16(INK4a) tumor suppressor.

Actinic keratoses (AKs) are pre-neoplastic lesions that can develop into squamous cell carcinomas (SCCs) of the skin. Often AK and SCC have commonly altered p53. A status of another tumor suppressor, the p16(INK4a), was reported for SCC but not for AK. A comparative study of SCC and AK human samples by loss of heterozygosity (LOH) analysis determined that the p16(INK4a/ARF) locus is less frequently altered in AKs than in SCCs. These LOH data highly correlated with immunohistochemical findings demonstrating the presence of p16(INK4a) in the AK skin samples but its absence in SCC lesions. Our results imply that progression of AK into SCC may involve inactivation of p16(INK4a).     

Hypermethylation-associated inactivation of p14(ARF) is independent of p16(INK4a) methylation and p53 mutational status

The INK4a/ARF locus encodes two cell cycle-regulatory proteins, p16INK4a andp14ARF, which share an exon using different reading frames. p14ARF antagonizes MDM2-dependent p53 degradation. However, no point mutations in p14ARF not altering p16INK4a have been described in primary tumors. We report that p14ARF is epigenetically inactivated in several colorectal cell lines, and its expression is restored by treatment with demethylating agents. In primary colorectal carcinomas, p14ARF promoter hypermethylation was found in 31 of 110 (28%) of the tumors and observed in 13 of 41 (32%) colorectal adenomas but was not present in any normal tissues. p14ARF methylation appears in the context of an adjacent unmethylated p16INK4a promoter in 16 of 31 (52%) of the carcinomas methylated at p14ARF. Although p14ARF hypermethylation was slightly overrepresented in tumors with wild-type p53 compared to tumors harboring p53 mutations [19 of 55 (34%) versus 12 of 55 (22%)], this difference did not reach statistical significance. p14ARF aberrant methylation was not related to the presence of K-ras mutations. Our results demonstrate that p14ARF promoter hypermethylation is frequent in colorectal cancer and occurs independently of the p16INK4a methylation status and only marginally in relation to the p53 mutational status.     

不同宫颈组织中PIK3CA、PTEN和p16蛋白表达及其与HPV16/18感染的关系

 目的 探讨PIK3CA、PTEN和p16蛋白在人正常宫颈上皮、宫颈上皮内瘤变（cervical intraepithelial neoplasia,CIN） 和宫颈鳞癌组织中的表达,以及PIK3CA、PTEN和p16蛋白表达与人乳头瘤病毒（human papillomavirus,HPV）感染 之间的关系。方法采用免疫组织化学二步法在22例健康者宫颈组织、72例宫颈上皮内瘤变（cervical intraepithelial neoplasia,CIN）和30例宫颈鳞癌组织中检测PIK3CA、PTEN和p16蛋白的表达,显色原位杂交方 法检测高危型HPV16/18的感染。结果PIK3CA和p16蛋白表达阳性率和HPV16/18的感染率均随着宫颈上皮逐渐恶变而 上升,PTEN蛋白表达却 呈现相反的结果。PIK3CA、PTEN、p16蛋白和 HPV16/18的感染率在宫颈鳞癌和CIN Ⅱ～Ⅲ组中的表达分别与对照组和CIN Ⅰ组相比,差异均有统计学意义（P＜ 0.05）。在宫颈上皮内瘤变组织中,39例（76.47%）CIN Ⅱ～Ⅲ 中显示PIK3CA阳性,仅有9例 （42.86%）CIN Ⅰ中显示 PIK3CA阳性,两组间差异有统计学意义（P=0.006）,而PTEN和p16蛋白在宫颈上皮内瘤 变不同组别中相比差异均无统计学意义。在81例CIN Ⅱ～Ⅲ和鳞癌组织中,PIK3CA和p16蛋白呈显著正相关关系 （P=0.000,r=0.544）。PIK3CA、p16蛋白与PTEN蛋白表达之间,两者均呈显著负相关（P＜0.05）。 HPV16/18阳性的47例标本中,PIK3CA和p16蛋白几乎均呈阳性表达,呈显著正相关（P<0.01）,但PTEN蛋白却有37例呈阴性表达,无显著相关（P=0.116）。结论PIK3CA、PTEN、p16蛋白表达以及高危型HPV感染与宫颈癌的发生发展均密切相关。PIK3CA、PTEN、p16蛋白和高危型HPV感染联合检测,可作为宫颈癌早期癌变的分子标志物。高危型HPV感染可能有助于PIK3CA和p16蛋白的高表达。     

Aberrant expression of pRb, p16, p14ARF, MDM2, p21 and p53 in squamous cell carcinomas of lung.

Expression of cell cycle regulatory proteins in both the RB and p53 pathways was investigated in 50 cases of squamous cell carcinoma (SCC) of the lung using immunohistochemical techniques. Abnormality of pRb and p16 expression was seen at the frequencies of 16% and 78%, respectively, and appeared to be in a reciprocal relationship. On the other hand, strong and diffuse p53 immunoreactivity was seen in 60% of SCCs. MDM2 and p14ARF expressions were each observed in about half of the cases of SCC and were not significantly associated with strong p53 immunoreactivity. Statistical analysis revealed that p14ARF expression was significantly correlated with both p16 and MDM2 expression. Moreover, strong p53 expression was not correlated with the expression of p21. In comparing clinicopathological status with the immunohistochemical results, lack of p16 immunoreactivity was observed in the elderly group (over 65 years) as compared with the younger group (less than 65 years). Strong p53 expression was frequently observed in higher stages of SCC, with the developing tumor located in the central field of the lung. Similarly, the frequency of p14ARF expression was high in centrally developed SCC, but low in SCC developed in the periphery. These results suggest that disruption of the RB and p53 pathways is a frequent event in SCC, and that abnormal expression of p16 and p53 plays a more critical role than that of pRB, p14ARF and MDM2 in the development of SCC of the lung.     

高危型HPV负荷量和p16INK4A蛋白监测评估宫颈锥切术治疗CIN

[目的]评价高危型人乳头状瘤病毒HPV负荷量的检测和p16INK4A蛋白的表达在预测宫颈上皮内瘤变(CIN)宫颈锥切术后残存病变或复发中的意义.[方法]回顾性分析142例2008年10月至2010年12月因CIN行宫颈锥形切除术治疗患者的临床资料.所有患者均于宫颈锥形切除术前6个月以内和术后6～12个月进行HPV负荷量检测,并采用免疫组化方法检测HPV DNA阳性患者宫颈细胞中p16INK4A蛋白表达.[结果]宫颈锥切术前,随着CIN级别的上升,HPV负荷量以及p16INK4A蛋白表达均明显增强(P＜0.05).但在宫颈锥切术后,HPV负荷量和p16INK4A蛋白表达明显降低,宫颈锥切术前和术后两者之间差异有统计学意义(P＜0.05).[结论] HPV负荷量持续增高和p16INK4A蛋白持续呈强阳性是宫颈锥切术后发生残存病变或复发的高危因素,在监测HPV负荷量的同时检测p16INK4A蛋白的表达,对判断宫颈锥切术后发生残存病变或复发有重要意义.