Fragile histidine triad expression delays tumor development and induces apoptosis in human pancreatic cancer.

The fragile histidine triad (FHIT) gene is a tumor suppressor gene that is altered by deletion in a large fraction of human tumors, including pancreatic cancer. To evaluate the potential of FHIT gene therapy, we developed recombinant adenoviral and adenoassociated viral (AAV) FHIT vectors and tested these vectors in vitro and in vivo for activity against human pancreatic cancer cells. Our data show that viral FHIT gene delivery results in apoptosis by activation of the caspase pathway. Furthermore, Fhit overexpression enhances the susceptibility of pancreatic cancer cells to exogenous inducers of apoptosis. In vivo results show that FHIT gene transfer delays tumor growth and prolongs survival in a murine model mimicking human disease.     

Fragile histidine triad expression in oral squamous cell carcinoma and precursor lesions.

PURPOSE: Fragile histidine triad (FHIT) expression in precursor oral lesions (POL) and oral squamous cell carcinomas (OSCC) was studied with regard to (a) the frequency of loss of FHIT expression, (b) whether loss of FHIT expression correlates with degree of dysplasia in POLs, (c) whether FHIT loss predicts high-risk POLs that are more likely to transform, and (d) whether FHIT loss in OSCCs correlates with survival. EXPERIMENTAL DESIGN: Ninety-four POLs and 86 OSCCs were immunostained for FHIT. Survival analysis was done for cases with validated clinical outcomes. RESULTS: By optimizing the immunostaining protocol, we found that FHIT is expressed in a distinctive strong nuclear and weak cytoplasmic pattern in oral tissues. Loss of FHIT expression was found in 42 of 94 (45%) POLs and in 66 of 86 (77%) OSCCs. We observed a statistically significant positive correlation between frequency of FHIT loss and increasing grade of dysplasia (chi2=13.8; degrees of freedom=4; P=0.008). Loss of FHIT expression in POLs that progressed to malignancy was more frequent than in those that did not [17 of 25 (68%) versus 12 of 29 (41.4%), respectively]. This difference was statistically significant (chi2=3.8; degrees of freedom=1; P=0.046). In OSCCs, loss of FHIT staining indicated a worse prognosis (survival rate, 36.2%) than when positive FHIT staining was observed (survival rate, 50%), but the difference was not statistically significant (P=0.546, Kaplan-Meier, log-rank). CONCLUSIONS: FHIT seems to localize to both nuclear and cytoplasmic domains. FHIT inactivation occurs early in oral carcinogenesis and may be useful molecular marker for progressive dysplastic oral lesions.     

Fragile histidine triad gene expression and its corralation with mismatch repair protein in human sporadic colorectal carcinoma

TheFragileHistidineTriad(FHIT)gene,encompassingtheFRA3Bfragilesiteatchromosome3pl4.2,isacandidatetumorsuppressorgeneinvolvedinmultipletumortypesincludingcolorectalcarcinomas[1,2].LossofDNAmismatchrepairisacommonfindinginhereditarynonpolyposiscoloncancer(HNPCC)aswellasinmanytypesofsporadichumantumors[3,4].RecentstudieshavesuggestedthatFHITgeneexpressioninactivationcanbeaconsequenceofdefectsinmismatchrepairproteins,particularlyMLH1andMSH2[5].Tolookintothissituation,weusedimmunohistoc…     

Tumorigenicity of the E6 and E6-E7 gene constructions derived from human papillomavirus type 33.

Human papillomavirus type 33 (HPV33) belongs to the group of HPV types frequently found in severe cervical dysplasias and carcinomas. By analogy with HPV types 16 and 18 selectively expressing E6 and E7 genes in malignant tissues, we studied the HPV33 E6 and E7 open reading frames in various configurations with upstream promoter and noncoding region (NCR) known to contain a particular 78-bp tandem repeat. HPV DNA fragments were cloned into expression vectors between the SV40 or the mouse metallothionein I promoter and the neo gene, transfected into NIH3T3 cells, selected by neo resistance, and inoculated into nude mice. In these bioassays, a weak transforming activity was detected for E6 open reading frame, and could be significantly enhanced either by the NCR or the E7 open reading frame. No tumorigenicity could be detected for E7 alone or in configuration with the upstream NCR. Further analyses of tumor cells showed that HPV33-derived genes were not sufficient to induce an anchorage-independent phenotype and, interstingly, there was no requirement for virus-transfected tumor cells to retain HPV sequences during tumor progression. We concluded that the transformation function of HPV33 resides in E6 gene as assayed by tumorigenicity. An enhancer of the E6 promoter is located in the NCR. On the other hand, in the absence of the NCR, E6 tumorigenicity may be augmented by the E7.     

Clinicopathological significance of fragile histidine triad transcription protein expression in breast carcinoma.

The fragile histidine triad (Fhit) gene, which is frequently lost in many cancers, was identified as a candidate tumor suppressor gene at chromosome 3p locus 14.2. Loss of Fhit expression is an important step in tumor progression from premalignancy, to in situ, to invasive breast carcinoma. To determine whether the absence of Fhit protein correlates with other established pathological-clinical parameters or prognosis, we assessed Fhit expression using immunohistochemistry in 166 invasive breast carcinomas. Lost or significantly decreased Fhit protein expression was identified in 70 cases (42.2%). Fhit expression was inversely correlated with histological grade (P < 0.0001), negative estrogen receptor status (P = 0.0016), p53 overexpression (P = 0.0040), and tumor proliferation activity (P = 0.0006). Survival curves determined by the Kaplan-Meier method and univariate analysis demonstrated that reduced expression of Fhit was associated with a poor outcome (P = 0.0086, by log-rank test). Multivariate analysis using the stepwise Cox proportional hazard model showed that lymph node metastasis was related to poor survival rates; in addition, patients with loss of Fhit expression still tended to have poor survival (P = 0.0563). Therefore, loss of Fhit expression is associated with higher malignant phenotypes and appears to be a prognostic factor in breast carcinoma.     

高危型HPV E6/E7 mRNA检测对宫颈高级别病变的预警分流价值

目的:通过比较检测HPV E6/E7 mRNA和HPV DNA两种HPV检测方法对宫颈高级别病变的检出能力,探讨HPV E6/E7 mRNA检测在宫颈癌筛查中的预警分流价值。方法:采集2016年7月至2017年6月就诊于我院接受宫颈癌筛查的1 515例女性宫颈脱落细胞,利用转录介导扩增法检测高危型HPV E6/E7 mRNA（n=505）和PCR+膜杂交法检测HPV DNA（n=1 010）,以组织病理学诊断为金标准,比较两种检测方法对宫颈高级别病变检出率。结果:利用HPV E6/E7 mRNA检测组阴道镜转诊率32.69%（17/52）、HPV DNA检测组阴道镜转诊率10.62%（12/113）,差异有统计学意义（P＝0.001）;HPV E6/E7 mRNA检测组CIN2+的检出率42.42%;HPV DNA组 CIN2+的检出率28.16%,差异有统计学意义（P＝0.034）。结论:与HPV DNA检测方法相比,HPV E6/E7 mRNA检测对CIN2+病变预警分流价值较高。     

小干扰RNA抑制宫颈癌Hela细胞株HPV18 E6、E7基因的表达

目的:以人乳头瘤病毒(human papillomavirus,HPV)18型E6基因为靶点,研究小干扰RNA(small interference RNA,siRNA)对宫颈癌Hela细胞株HPV18基因组中恶性转化基因E6、E7的抑制作用及对细胞内P53蛋白表达的影响。方法:实验分细胞培养液阴性对照组(阴性对照组),无关序列siRNA对照组(无关序列对照组)及转染HPV18 E6-siRNA实验组(siRNA实验组)。设计并合成HPV18 E6-siRNA及无关序列siRNA,转染Hela细胞后,RT-PCR检测转染后48、120 h细胞内HPV18E6、E7mRNA的变化,Western blotting检测转染后48 h细胞内HPV18 E7和P53蛋白的变化。结果:siRNA转染Hela细胞的效率约为85%。siRNA转染后48 h,实验组细胞内HPV18E6、E7mRNA及E7蛋白含量降低,其含量分别为阴性对照组的33.33%、36.78%及33.84%;实验组细胞内P53蛋白含量增加,其含量为阴性对照组的2.194倍。siRNA转染后120 h,实验组细胞HPV18E6、E7mRNA含量恢复为阴性对照组的90.91%、101.60%。结论:HPV18 E6-siRNA体外能明显抑制宫颈癌Hela细胞HPV18E6、E7基因的表达,增加细胞内肿瘤抑制因子P53蛋白的水平。     

High-risk human papillomavirus E7 oncoprotein detection in cervical squamous cell carcinoma.

PURPOSE: Persistent infections by high-risk human papillomavirus (HPV) types are the main etiologic factor for cervical cancer. The objective of this study was to evaluate whether high-risk E7 oncoprotein is adequate as a marker for the detection of cervical cancer. EXPERIMENTAL DESIGN: HPV typing was done in biopsies from 58 cervical carcinoma and 22 normal cervical squamous epithelia. The HPV-16 E7, HPV-18 E7, and HPV-45 E7 oncoprotein levels were monitored by immunohistochemistry and compared with those of p16(INK4a) and Ki67. RESULTS: Fifty-five (94.8%) tumors were high-risk HPV-DNA-positive (46 HPV-16, 2 HPV-16 and HPV-18, 4 HPV-18, 1 HPV-33, and 2 HPV-45). HPV-DNA could not be detected in three tumors (5.2%). High HPV E7 oncoprotein levels were shown in 57 cervical cancers (98.3%), without correlation between expression levels and tumor stages. CONCLUSION: This is the first study which systematically analyzes the levels of the major HPV oncoproteins in cervical carcinomas demonstrating that the high-risk HPV E7 proteins are regularly expressed in these cancers. This suggests that high-risk E7 oncoproteins are necessary for cervical cancers and apparently essential as tumor marker.     

Diagnostic and prognostic validity of the human papillomavirus E6/E7 mRNA test in cervical cytological samples of HC2-positive patients

The study aimed to assess the clinical utility in identifying CIN2 or worse (CIN2+), of the Pretect HPV-Proofer test for E6/E7 mRNA detection in Hybrid Capture 2 (HC2)-positive patients, who underwent colposcopy. In particular, the study analyzed the mRNA test performance as the third test in a subgroup of HC2+ patients with less severe than high-grade squamous intraepithelial lesions (HSIL-). We analyzed 464 cervico-vaginal samples by liquid-based cytology (LBC) and PreTect HPV-Proofer. Moreover 231 patients also had a biopsy at baseline and 75, with HSIL-, were followed up within 2 years by LBC, colposcopy, and histology when indicated. The highest sensitivity for CIN2+ belonged to the mRNA compared to LBC, at the HSIL+ threshold (72% vs. 58%), whereas the LBC showed the highest specificity and positive predictive value (PPV) (99 and 93% vs. 73 and 39%, respectively). Focusing on the 408 HSIL- patients, the mRNA positivity was significantly more associated with CIN2+ than CIN2- lesions (p < 0.0001). Moreover, among the 75 HSIL- followed up patients, the mRNA displayed high longitudinal Specificity (89%), even if the sensitivity and the PPV were low (50 and 20%, respectively). The present data suggest that the mRNA test may have a diagnostic and a potentially prognostic role in HC2+/HSIL- patients.     

Dissection of human papillomavirus E6 and E7 function in transgenic mouse models of cervical carcinogenesis

Human cervix cancer is caused by high-risk human papillomaviruses encoding E6 and E7 oncoproteins, each of which alter function of distinct targets regulating the cell cycle, apoptosis, and differentiation. Here we determined the molecular contribution of E6 or E7 to neoplastic progression and malignant growth in a transgenic mouse model of cervical carcinogenesis. E7 increased proliferation and centrosome copy number, and produced progression to multifocal microinvasive cervical cancers. E6 elevated centrosome copy number and eliminated detectable p53 protein, but did not produce neoplasia or cancer. E6 plus E7 additionally elevated centrosome copy number and created large, extensively invasive cancers. Centrosome copy number increases and p53 loss likely contributed to malignant growth; however, dysregulated proliferation and differentiation were required for carcinogenic progression.     

High-risk human papillomavirus E6/E7 mRNA and L1 DNA as markers of residual/recurrent cervical intraepithelial neoplasia

The aim of this study was to assess the use of human papillomavirus (HPV) E6/E7 mRNA testing in the follow-up of women treated for cervical intraepithelial neoplasia (CIN) by conization and to compare the prognostic value of HPV E6/E7 mRNA to HPV L1 DNA and cytology. One hundred and forty-three women underwent cytological/histological testing, HPV DNA genotyping by Linear Array, and HPV E6/E7 mRNA testing by APTIMA HPV assay during follow-up after surgical treatment for histologically verified CIN. High-grade residual/recurrent disease (CIN2+/HSIL+) was identified in 7 (4.9%) women, and low-grade disease (CIN1/LSIL) in 25 (17.5%). At the inclusion visit 33 (23%) women were HPV DNA-positive; 13 (9.0%) were HPV E6/E7 mRNA-positive. HPV E6/E7 mRNA did not identify three women with high-grade disease. Presence of high-risk HPV DNA at the inclusion visit predicted 100% (95% CI 64.6-100) of high-grade residual/recurrent disease, with a specificity of 80.9% (95% CI 73.5-86.6); cytology had a sensitivity of 85.7%, and a specificity of 87.5%. HPV E6/E7 mRNA testing was a poor predictor of treatment failure, with a sensitivity of 57.1% (95% CI 25.0-84.2), but high specificity (93.4%; 95% CI 87.9-96.5). Detection of high-risk HPV DNA after treatment by conization identified 100% of women with residual/recurrent high-grade disease, whereas HPV E6/E7 mRNA testing was a poor predictor of treatment failure. This study suggests that a negative HPV mRNA result cannot exclude the risk of malignant progression, and that HPV E6/E7 mRNA testing by APTIMA HPV assay is not useful in the follow-up of women treated for CIN.     

Human papillomavirus 16 E6 and E7 are associated with the nuclear matrix of cervical carcinoma cells

Carcinoma of uterine cervix is closely associated with human papillomavirus (HPV) infection and HPV16 DNA has been shown to integrate into the genome of host cancer cells. The subgenomic fragments (E6E7) were found to be present in nuclear matrix (NM)-associated DNA by novel PCR. Further investigation showed the absence of E6 open reading frame (protein encoding sequence) in NM-associated DNA. DNA-protein binding assay (Southwestern blotting) labeled 2 groups of NM proteins that bound commonly to E6E7 DNA and specifically to either E6 or E7 DNA. Complex protein formation that was recognized by E6E7 was suggested. Further investigation into properties of these NM proteins may provide a better understanding of the role of HPV in cervical carcinogenesis.     

散发性结直肠癌组织中FHIT蛋白表达的研究

目的：探讨散发性结直肠癌组织中脆性组氨酸三联体（fragile histidine triad，FHIT）蛋白表达情况及其与临床病理指标之间的关系。方法：采用免疫组化SP法检测84例手术切除的散发性结直肠癌组织中FHIT蛋白的表达。结果：FHIT蛋白在84例散发性结直肠癌中表达阳性率为48．81％。FHIT蛋白低或不表达与患者的年龄、性别、肿瘤部位、组织学类型无关，P〉0．05；而与肿瘤浸润深度和分化程度、Duck’s分期和淋巴结转移有关，P〈0，05。在浸润深度越深、分化程度越低、Duck’s分期越晚和有淋巴结转移的癌组织中，FHIT蛋白低表达就越明显。结论：FHIT蛋白表达缺失可能参与散发性结直肠癌的演化和进展。     

散发性结直肠癌组织中FHIT蛋白表达的研究

目的:探讨散发性结直肠癌组织中脆性组氨酸三联体(fragile histidinetriad,FHIT)蛋白表达情况及其与临床病理指标之间的关系。方法:采用免疫组化SP法检测84例手术切除的散发性结直肠癌组织中FHIT蛋白的表达。结果:FHIT蛋白在84例散发性结直肠癌中表达阳性率为48·81%。FHIT蛋白低或不表达与患者的年龄、性别、肿瘤部位、组织学类型无关,P>0·05;而与肿瘤浸润深度和分化程度、Duck’s分期和淋巴结转移有关,P<0·05。在浸润深度越深、分化程度越低、Duck’s分期越晚和有淋巴结转移的癌组织中,FHIT蛋白低表达就越明显。结论:FHIT蛋白表达缺失可能参与散发性结直肠癌的演化和进展。     

rBCG-HPV16 E6-E7疫苗和rBCG-HPV16 L1-E7疫苗对人子宫颈癌小鼠的治疗作用和免疫机制研究

目的 研究rBCG-HPV16 E6-E7疫苗和rBCG-HPV16 L1-E7疫苗对子宫颈癌的治疗作用及免疫机制.方法 BALB/C鼠皮下接种人子宫颈癌细胞系CaSki细胞构建子宫颈癌模型,用本研究组制备的rBCG-HPV16 E6-E7疫苗和rBCG-HPV16 L1-E7疫苗皮下分别注射进行治疗,观察肿瘤的生长情况.结果 皮下注射rBCG-HPV16 E6-E7疫苗和rBCG-HPV16 L1-E7疫苗后,肿瘤体积显著缩小,小鼠存活期明显长于对照组,肿瘤瘤体内CD8 细胞浸润增加;肿瘤细胞表达H-2Db和B7-1分子明显增加.rBCG-HPV16 E6-E7疫苗效果强于rBCG-HPV16 L1-E7疫苗.结论 rBCG-HPV16 E6-E7疫苗和rBCG-HPV16 L1-E7疫苗对子宫颈癌有治疗作用.     

Selective suppression of monocyte chemoattractant protein-1 expression by human papillomavirus E6 and E7 oncoproteins in human cervical epithelial and epidermal cells

Infection of cervical keratinocytes by high-risk HPV is involved in the etiology of cervical carcinoma. Since viral products are immunogenic, development of cancer may require suppression of immune responses directed against infected epithelial cells. Many markers of host immune effector responses decrease as cervical intraepithelial neoplasia progresses. Among these is epithelial cell expression of the chemokine MCP-1, though the mechanism for its suppression is unclear. Here, we show that the E6 and E7 viral oncogenes from high-risk HPV, individually and together, suppress MCP-1 expression in primary epithelial cells derived from the female genital tract. This is not a consequence of global suppression of chemokine expression since other chemokines, including IP-10, IL-8 and RANTES, were less affected. Furthermore, 4 of 6 HPV-positive cervical carcinoma cell lines did not express MCP-1. Our data indicate that suppression of MCP-1 expression is part of the program of high-risk HPV E6/E7-induced transformation of primary epithelial cells. These observations are consistent with a model in which MCP-1 expression by infected keratinocytes, which would stimulate an immune attack on HPV-transformed cells, is suppressed for invasive cervical cancer to appear.