人卵巢浆液性囊腺癌中p16~(INK4a)基因失活机制探讨

目的 :探讨人卵巢浆液性囊腺癌中p16INK4a基因表缺失的机制 ,为p16INK4a相关性基因治疗提供理论依据。方法 :采用PCR、PCR SSCP、甲基化特异性PCR和DNA测序等方法重点检测p16INK4a蛋白表达缺失的卵巢浆液性肿瘤组织中p16INK4a基因缺失、突变和5’ CpG岛甲基化 ,分析它们与肿瘤预后的关系。结果 :4 3份p16INK4a蛋白表达阴性标本中检测到p16INK4a基因纯合缺失 4例 ,第 1、2外显子各 2例 ;第 2外显子点突变 2例 ,经DNA测序确定 1例为第 2外显子 4 94位G→T变异 ,位于非编码区 ;1例为第 2外显子 34 3位G→T变异 ,相应的氨基酸变异为第 115位缬氨酸 (GTG)→亮氨酸 (TTG) ;应用MSP法检测出 14例 (32 .6% ) 5’ CpG岛甲基化并经DNA测序证实。p16INK4a蛋白表达阳性的 14份标本中仅检测到 1例 (7.14% ) 5’ CpG岛甲基化 ,而未发现基因缺失和点突变证据。 34例卵巢浆液性囊腺癌患者中p16INK4a基因异常 16例 ,较无异常 18例预后更差 (P =0 .0 0 0 8)。结论 :5’ CpG岛甲基化可能是卵巢浆液性囊腺癌中p16INK4a基因表达缺失的主要原因 ,去甲基化治疗可能成为该类肿瘤一种有用的生物治疗方法     

p16^INK4a基因与宫颈癌

p16^INK4a基因在细胞周期调控RB通路中发挥着负反馈调节作用，决定着细胞周期的正常运转和细胞增殖、分化及凋亡，并与多种人类肿瘤的发生、发展、治疗与预后密切相关。综述p16^INK4a基因及其蛋白的表达在宫颈癌中的研究现状，发现p16^INK4a基因甲基化是宫颈癌发生的早期事件，p16^INK4a在HPV阳性的宫颈上皮内瘤样病变，宫颈腺上皮内病变，宫颈鳞癌及腺癌（ADCA）中呈高表达，且随着病变加重表达增强，而正常宫颈上皮、间质、化生和炎性细胞p16^INK4a表达呈阴性，这一特性使得其在检测宫颈癌及其癌前病变、预测病变进展及判断预后等方面有潜在的临床应用价值。     

卵巢浆液性囊腺癌中MTS_1/p16基因突变及其蛋白表达的研究

目的：探讨抑癌基困MTS1／p16在人卵巢浆液性囊腺癌发生发展中的作用。方法：应用免疫组化检测10例正常卵巢组织,20例浆液性囊腺瘤,20例交界性策液性囊腺瘤,65例浆液性囊腺癌及有癌转移的阳性盆腔淋巴结中p16基因蛋白表达,用PCR－SSCP分析10例浆液性囊腺癌中有无p16基因第1、2外显子的突变。结果：正常卵巢、浆液性囊腺瘤、交界性浆液性囊腺瘤、浆液性囊腺癌及有癌转移的盆腔淋巴结中,p16基因蛋白表达阳性率分别为60％、55％、55％、12．3％、0％;10例浆液性囊腺癌均未发现p16基因第1、2外显子的突变。结论：p16基因功能失活可能与卵巢癌发生、发展相关,p16基因表达的检测可能成为判断浆液性卵巢肿瘤恶性度及预后的指标;浆液性卵巢癌p16基因突变率较低,可进一步扩大检测范围并作进一步研究。     

年轻女性子宫颈上皮内瘤变2级组织中p16^INK4a的表达及意义

目的探讨年轻女性宫颈上皮内瘤变（CIN）2级组织p16^INK4a的表达与病变级别及转归的相关性。方法选取2010年1—12月在北京大学第一医院妇产科门诊就诊的年龄≤35岁、经病理诊断的CIN2患者36例,按照年龄将其分为〈30岁组（12例）和30-35岁组（24例）,采用免疫组化法对其宫颈活检组织进行p16^INK4a检测,并采用两个结果判断标准对患者的转归进行随访。结果CIN2组织中p16^INK4a阴性、弱阳性和阳性（〉50％）的表达率分别为11．1％（4／36）、8．3％（3／36）和80．6%（29／36）;美国下生殖道鳞状上皮病变项目（LAST projet）分流标准p16^INK4a连续弥漫全层阳性的表达率为63．9％（23／36）。其中年龄〈30岁组p16^INK4a〉50％阳性和弥漫全层阳性患者中,宫颈环状电切术（LEEP）后诊断为CIN3的比例分别为1／9和1／7;而30-35岁组两者的比例分别为4／18和3／16,两者比较,差异均无统计学意义（P〉0．05）。36例患者平均随访（13．4±3．9）个月,未发现病变进展。结论对CIN2组织中p16^INK4a阳性患者进一步行LEEP或锥切是必要的;p16^INK4a对预测CIN转归的意义仍需进一步研究。     

宫颈癌及癌前病变中p16^INK4A与HPV的关系

高危型人乳头瘤状病毒（HR—HPV）持续感染宫颈后，通过其基因产物干扰正常的细胞周期调节，导致细胞的连续增殖与恶性转化。p16^INK4A基因产物是细胞周期素依赖性激酶抑制物（CDKI），负性调节细胞周期，由于HPVE7蛋白阻断了p16^INK4A的细胞周期调节级联，因此在HR—HPV感染的宫颈癌及癌前病变组织中出现p16^INK4A过表达。p16^INK4A与HPV联合监测将提高宫颈癌筛查的有效性，有助于宫颈癌的诊断与鉴别诊断。     

液基细胞标本中宫颈鳞状细胞核p16^INK4a染色计数的评价

p16^INK4a基因产物强烈表达于异常宫颈上皮细胞。为探讨p16^INK4a作为一种判断宫颈涂片或液基细胞标本中异常细胞的生物学标记物的价值进行研究。     

细胞周期p16-cyclin D1-pRb调节通路与人卵巢浆液性囊腺癌的相关性研究

目的 :探讨细胞周期 p16 - p Rb- cyclin D1调节通路及各因子在浆液性卵巢肿瘤发生和发展中的作用。方法 :应用免疫组化 L s AB法检测一组浆液性卵巢肿瘤中 p16、p Rb和 cyclin D1蛋白表达情况。结果 :卵巢浆液性囊腺癌原发灶和淋巴结转移灶中 p16表达阳性率明显低于正常卵巢、良性肿瘤和交界性肿瘤 ;p16 - p Rb- cyclin D1调节通路异常率却呈相反趋势变化 ,且通路异常与浆液性囊腺癌 FIGO分期、组织学分级及预后无明显相关性。 p16表达阳性患者术后生存率高于阴性患者 (P=0 .0 0 0 6 )。p Rb和 cyclin D1表达情况与卵巢浆液性囊腺癌组织学分级、FIGO分期无明显关系。卵巢浆液性肿瘤组织中 p16和 p Rb蛋白表达呈负相关。结论 :p16蛋白在卵巢浆液性肿瘤的发生、发展中可能起着较为重要的作用。 p16 - p Rb- cyclin D1调节通路异常在浆液性卵巢肿瘤虽很常见 ,但其具体作用尚不清楚     

卵巢恶性上皮性肿瘤组织中p16基因缺失的分析

卵巢恶性上皮性肿瘤组织中ｐ１６基因缺失的分析章小维张琼郭燕燕近年来的研究表明，细胞周期失控是癌变的重要原因。新发现的定位于人９ｐ２１区的ｐ１６基因，其产物是一个可特异性地影响细胞周期的调节因子，在人类多种肿瘤细胞系和肿瘤组织中，可以检测到ｐ１６基因纯...     

卵巢上皮性浆液性肿瘤p16mRNA与p16蛋白表达及其临床 …

目的 研究Ｐ１６抑癌基因与卵巢上皮性浆液性肿瘤发生与发展的关系。方法 应用原位杂交和免疫组化法,对４７份卵巢上皮性浆液性肿瘤组织和８份正常卵巢组织ｐ１６ｍＲＮＡ与ｐ１６蛋白进行检测。结果 ｐ１６ｍＲＮＡ与Ｐ１６蛋白阳性表达皆主要位于胞浆内,呈红色颗粒状,阳性表达细胞多呈灶状分布。ｐ１６ｍＲＮＡ与Ｐ１６蛋白在卵巢浆液性癌中检出率（４８．５％、４２．４％）皆低于良笥浆液性瘤（均９０．０％）及正常卵组织     

p16INK4a基因与宫颈癌

p16INK4a基因在细胞周期调控RB通路中发挥着负反馈调节作用,决定着细胞周期的正常运转和细胞增殖、分化及凋亡,并与多种人类肿瘤的发生、发展、治疗与预后密切相关.综述p16INK4a基因及其蛋白的表达在宫颈癌中的研究现状,发现p16INK4a基因甲基化是宫颈癌发生的早期事件,p16INK4a在HPV阳性的宫颈上皮内瘤样病变,宫颈腺上皮内病变,宫颈鳞癌及腺癌(ADCA)中呈高表达,且随着病变加重表达增强,而正常宫颈上皮、间质、化生和炎性细胞p16INK4a表达呈阴性,这一特性使得其在检测宫颈癌及其癌前病变、预测病变进展及判断预后等方面有潜在的临床应用价值.     

Abnormalities of the RB1 pathway in ovarian serous papillary carcinoma as determined by overexpression of the p16(INK4A) protein.

Dysfunction of proteins involved in the G1 to S transition of the cell cycle, such as p16(INK4A) and RB1, is common in many cancer types. A screen of p16 protein expression was performed in benign, borderline, and invasive ovarian tumors, together with endometrial cancers, aligned on a tissue microarray. We observed frequent p16 overexpression in serous papillary carcinomas of ovarian and endometrial origin. An extended cohort of ovarian serous papillary carcinomas was examined to further evaluate the frequency of p16 overexpression. Strong, uniform staining in the majority of cancer cells occurred commonly in invasive serous papillary ovarian cancers, particularly in grade 3 carcinomas. RB1 protein expression abnormalities were rare. Our data indicate that abnormalities in the retinoblastoma pathway, as determined by p16 overexpression, are common in serous papillary carcinomas and are probably an early event.     

卵巢上皮性癌组织中p16INK4A基因表达缺陷的意义及其与甲基化的关系

目的研究抑癌基因p16INK4A在卵巢上皮性癌(卵巢癌)组织及细胞系中的表达变化,分析其表达变化与甲基化的关系。方法选取7种卵巢癌细胞系、18份卵巢癌组织和10份正常卵巢组织为研究对象。采用甲基化特异性PCR方法检测p16INK4A基因甲基化状态;RT-PCR技术检测p16INK4A基因的mRNA表达;蛋白印迹(western blot)法检测P16INK4A蛋白的表达。5-杂氮-2′-脱氧胞苷对p16INK4A基因甲基化的卵巢癌细胞进行去甲基化处理,再次进行p16INK4A基因的mRNA和蛋白表达的检测,以及p16INK4A基因甲基化的分析。检测5-杂氮-2′-脱氧胞苷处理前后卵巢癌细胞的生长情况;并将处理前后的细胞接种于裸鼠,观测肿瘤的体积、重量。结果3种卵巢癌细胞系(Anglne、SW626和OVCAR3细胞)、6份卵巢癌组织中存在p16INK4A基因甲基化,卵巢癌细胞和卵巢癌组织中的甲基化率分别为3/7和33%(6/18)。卵巢癌细胞系、卵巢癌组织和正常卵巢组织中,p16INK4A基因的mRNA相对含量的平均值分别为0·34±0·11、0·81±0·13、1·52±0·12,蛋白相对含量的平均值分别为0·56±0·14、1·32±0·12、2·09±0·11,卵巢癌细胞系、卵巢癌组织分别与正常卵巢组织相比,差异均有统计学意义(P<0·05)。有甲基化表现的卵巢癌细胞和组织中p16INK4A基因的mRNA和蛋白表达均下降。5-杂氮-2′-脱氧胞苷处理能使p16INK4A基因甲基化的卵巢癌细胞中的p16INK4A基因的mRNA和蛋白重新表达或表达增高。与去甲基化处理前比较,去甲基化处理后Anglne、SW626和OVCAR3细胞的生长速度均减慢;接种去甲基化处理的OVCAR3细胞的裸鼠中,肿瘤体积和重量明显减小,分别为(0·243±0·022)cm3、(0·035±0·004)g。结论p16INK4A基因的表达下降或缺失在卵巢癌的发生中起重要作用,DNA甲基化是其表达缺陷的原因,去甲基化处理可以恢复p16INK4A基因的表达并抑制卵巢癌细胞的增殖。     

p16INK4a overexpression independent of human papillomavirus infection in lobular endocervical glandular hyperplasia.

A high rate of human papillomavirus (HPV) infection has been reported in cervical cancer and precancerous lesions. Many studies also have shown that p16INK4a overexpression is of diagnostic value for high-risk HPV-related cervical cancer and precursors. Lobular endocervical glandular hyperplasia (LEGH) is a rare lesion of the uterine cervix. There is one report about HPV infection and few studies on p16INK4a expression in LEGH. Therefore, we 1) detected HPV infection and examined p16INK4a expression and 2) observed the relationship between HPV and p16INK4a overexpression in LEGH. The immunohistochemical expression of p16INK4a was studied in 24 cases of LEGH. HPV DNA was also evaluated in these cases using a polymerase chain reaction technique. Strong (++) p16INK4a immunoreactivity was observed in 10 (41.7%) of the 24 LEGH cases; a moderate (+) pattern was observed in 9 (37.5%) cases; a weak (+) pattern was observed in 2 (8.3%) cases; and the remaining 3 (12.5%) cases showed negative expression. Overall, p16INK4a overexpression was seen in 87.5% of the cases (21/24). HPV DNA was not detected in any of the 24 LEGH cases. These results suggest that p16INK4a overexpression is independent of HPV infection in LEGH.     

Evaluation of a region on chromosome 1p in ovarian serous carcinoma that is frequently deleted in uterine papillary serous carcinoma.

OBJECTIVE: The goal of this study was to assess the involvement of chromosome 1p deletion in ovarian papillary serous carcinoma (OPSC) via high-resolution physical mapping to detect a candidate tumor suppressor gene previously implicated in uterine papillary serous carcinoma (UPSC) tumorigenesis. METHODS: Previous studies have demonstrated a high rate of loss of heterozygosity (LOH) within a critical region of chromosome 1p in UPSC, suggesting the presence of a putative tumor suppressor gene important in the development of UPSC. To compare the genetic changes in OPSC with those in UPSC, seven microsatellite repeat polymorphisms were used to evaluate LOH in primary OPSC specimens. Allelic intensity was compared between normal and tumor DNA from microdissected, formalin-fixed, paraffin-embedded specimens. In addition to the same seven 1p markers used for UPSC, three additional non-1p markers for chromosomes 1q, 11q, and 2p were tested to determine a baseline rate of LOH. RESULTS: Overall, 26.6% (8/30) of OPSC (vs 63.2% of UPSC) were characterized by loss at either of the two loci that define the critical region for UPSC. Rates of LOH at each of the 1p loci in the OPSC tumors ranged from 5.6 to 38.9%, which are compatible with background rates of loss for OPSC. LOH at non-1p loci was 29.2%. CONCLUSION: While a tumor suppressor gene on 1p appears to be an important genetic event in the development of UPSC, a similar rate and pattern of loss on 1p are not identified in OPSC. Thus, despite the striking clinical similarities between UPSC and OPSC, tumorigenesis in these carcinomas appears to occur via distinctly different pathways.     

Correlation of p16INK4A overexpression with human papillomavirus infection in cervical adenocarcinomas.

SUMMARY: As human papillomavirus (HPV) infection is the main risk factor for squamous cell carcinoma of the cervix and overexpression of p16INK4a occurs when retinoblastoma protein is inactivated by high-risk HPV, the authors studied the association of HPV infection and expression of p16INK4a in cervical adenocarcinomas. Specimens of cervical glandular neoplasias were immunostained with a p16INK4a-specific monoclonal antibody (clone E6H4). Approximately 80% of glandular neoplasms showed overexpression of p16INK4a. Exfoliated cells from 14 adenocarcinomas were further examined by p16INK4a-specific immunocytochemistry, and 12 cases showed overexpression of p16INK4a, suggesting that immunostaining for p16INK4a may be a useful diagnostic tool for cervical adenocarcinomas. The authors further examined HPV DNA in cervical adenocarcinomas with the polymerase chain reaction method. Overexpression of p16INK4a was positive in 94% of cases in which HPV16 or 18DNA was positive, a finding suggesting that HPV16 or 18 may play an important role in cervical adenocarcinomas. Overexpression of p16INK4a may be an indicator of pathogenic activity of high-risk HPVs.     

p16~(INK4A)、P14~(ARF)蛋白在宫颈鳞癌中的表达及意义

目的:研究p16INK4A和p14ARF蛋白在各级宫颈病变中的表达特征和临床意义。方法:采用免疫组织化学S-P法对95例宫颈鳞癌(SCC)标本、80例宫颈上皮内瘤变(CIN)标本和45例正常宫颈标本进行p16INK4A和p14ARF蛋白的检测。结果:按正常宫颈-CINⅠ-CINⅡ-CINⅢ-宫颈鳞癌的顺序,p16INK4A及p14ARF的阳性率逐渐升高,具显著性差异(P<0.01),p16INK4A和p14ARF在各级宫颈病变中的表达呈正相关(r=1)。宫颈鳞癌组织中,p16INK4A、p14ARF在临床Ⅱ期中的阳性率(分别为98.3%、96.6%)均高于临床Ⅰ期的阳性率(分别为83.8%、78.4%),差异有显著意义(P1=0.025,P2=0.013);随着病理分级由Ⅰ级→Ⅲ级,p16INK4A、p14ARF的阳性率从低到高,呈正相关(r=1);p16INK4A、p14ARF与淋巴结转移无关(P>0.05)。结论:p16INK4A和p14ARF蛋白的阳性表达与宫颈疾病的严重程度密切相关,在宫颈鳞癌的形成及进展中起重要作用,p16INK4A和p14ARF蛋白基因有可能成为预测宫颈鳞癌发生及病程进展的生物学检测指标。