hMLH1 Expression Research Articles

Primary ovarian squamous cell carcinoma: clinicopathological features and prognostic analysis of fifteen cases

Objective: To assess the clinical features and treatment outcomes in patients with primary ovarian squamous cell carcinoma (POSCC). Methods: Fifteen patients with primary ovarian squamous cell carcinoma diagnosed from January 2009 to December 2018 in Cancer Hospital of the University of Chinese Academy of Sciences were collected. The expression of p16, hMLH1, hMSH2, hMSH6 and PMS2 in POSCC was detected by immunohistochemistry, and the status of high-risk human papillomavirus (HPV) by RNAscope test. Results: Squamous cell carcinoma with different degrees of differentiation was found in 15 cases, including three cases with high differentiation and 12 cases with medium to low differentiation. There were four cases with in situ squamous cell carcinoma, four cases with teratoma, one case with endometrial carcinoma/atypical hyperplasia, and one case with endometriosis. p16 was expressed in five cases (5/15), indicating coexisting high-risk HPV infection. There was no high-risk HPV infection in the remaining 10 cases, and p16 staining was negative. There was no deficient mismatch repair protein in all cases. The overall survival time (P=0.038) and progression free survival (P=0.045) of patients with high-risk HPV infection were longer than those without HPV infection. Conclusions: POSCC is more commonly noted in postmenopausal women and often occurs unilaterally. Elevated serological indexes CA125 and SCC are the most common finding. Morphologically, the tumors show variable degrees of differentiation, but the current data suggest that the degree of differentiation cannot be used as an independent prognostic index. High-risk HPV infection may be associated with the occurrence of POSCC, and that the prognosis of POSCC patients with HPV infection is better than that of patients without infection.

Relation between expression of hMLH1 and p53 mRNA genes, in the feces of patients with colorectal carcinoma. Cross-sectional study

Colorectal carcinoma (CRC) is one of the main public health problems. The mortality of CRC is about 8%. Early detection of CRC is very important to prevent death because this cancer could be cured through surgery if the diagnosis can be made as early as possible. Therefore screening strategy for early detection of CRC is critical in reducing mortality. Many investigations supporting the detection of CRC have been developed, including the fecal DNA mutation test using advanced cytological techniques. It is capable of assessing colonocytes for the presence of DNA, RNA, and protein as molecular biomarkers of neoplasia in CRC, including p53 and hMLH1. This study implemented observational approach with a cross-sectional study of the feces of patients with CRC regardless of the stage and grade. The purpose of this study was to determine the expression of the hMLH1 and p53 mRNA genes in the feces of 48 patients with CRC from two hospitals in Indonesia, Siloam Hospitals in Cikarang and Dr. Wahidin Sudirohusodo Hospital in Makassar. The results showed that all adenocarcinoma feces samples with various tumor stages and grades had excess mRNA expression (more than twice the normal amount in Fold Change units) for both the hMLH1 and p53 genes. The average expression of the hMLH1 mRNA gene was the highest at stage two and grade one, while the lowest was at stage four and grade three. In contrast, the average p53 mRNA gene expression was the highest at stage four and grade three, while the lowest was at stage two and grade one. The study suggested that there was a relation between and the expression of hMLH1 and p53 mRNA gene. We concluded that while both hMLH1 and p53 genes in patients’ feces with CRC were overexpressed, they did not significantly affect the grade of CRC.

Microsatellite Instability Assessment by Immunohistochemistry in Acute Myeloid Leukemia: A Reappraisal and Review of the Literature

Microsatellite instability (MSI) is caused by defects in DNA mismatch repair (MMR) components. Inactivation of any MMR gene(s), including hMLH1, hMSH2, hMSH6, and hPMS2, can result in MSI. Immunohistochemistry (IHC) is a sensitive and specific screening tool for MSI that can detect loss of expression of one or more MMR components. Of the four MMR markers, hMLH1 and hMSH2 are considered most informative of MSI status. There has been renewed interest in MSI status in view of its favorable association with response to immune checkpoint inhibitors in some cancers. MMR expression patterns in acute myeloid leukemia (AML) have not been evaluated systematically. We used clinically-validated IHC assays to assess the expression of hMLH1, hMSH2, hMSH6, and/or hPMS2 in formalin-fixed paraffin-embedded tissue sections of bone marrow core biopsies from patients diagnosed with AML. Mutation profiling was performed using next-generation sequencing to assess for mutations in MMR genes. The study group included 236 patients with AML, including a cohort treated on a clinical trial of azacitidine and nivolumab (NCT02397720). In addition, hMSH6, and/or hPMS2 expression was assessed in 99 AML patients with diploid karyotype. All patients, except two, had retained expression of all MMR markers assessed: One patient from the azacytidine+nivolumab group had zonal patchy loss of staining of hMLH1 and, to a lesser extent, a similar staining pattern of hMSH2; and one patient from the AML with diploid karyotype group had loss of hMSH2 but retained expression of hMLH1, hMSH6 and hPMS2. In addition, a retrospective analysis on a separate cohort of 139 patients with primary AML, on which next generation sequencing profiling was performed, identified 14 cases with alterations in MMR genes. MMR loss is a rare event in AML, thus does not appear to underlie response patterns to anti-PD1 therapy.

MMR-proficient and MMR-deficient colorectal cancer cells: 5-Fluorouracil treatment response and correlation to CD133 and MGMT expression

Cancer stem cells (CSCs) from colorectal cancer (CRC), characterized by CD133 expression, have been associated with 5-fluorouracile (5-FU) chemoresistance. DNA repair mechanisms, such as O6-alkylguanine DNA alkyltransferase (MGMT) and mismatch repair (MMR) systems, have also been correlated to 5-FU resistance in CRC. The aim of this study was to evaluate the modulation of CD133 and MGMT in MMRproficient and MMR-deficient CRC cells under 5-FU treatment and the effect of this drug in CSCs. CD133 and MGMT methylation status were determined in MMR-proficient (SW480 and HT29) and MMR-deficient (RKO and HCT116) cell lines by methylation-specific PCRs. SW480 and RKO were selected to determine modulation of CD133, MGMT and MMR expression after 5-FU treatment by qPCR. In addition, CD133, MGMT and MMR were analyze in SW480 and RKO CSCs. No association between promoter methylation and MGMT and CD133 expression was found. 5-FU treatment increased CD133 expression independently to MMR status in SW480 and RKO and was able to increase hMLH1 expression in RKO, a MMR-deficient cell line. RKO/ CSCs overexpressed CD133 and MMR (hMSH2 and hMSH6) while SW480/CSCs showed a significant increase in CD133, MMR (hMLH1, hMSH2 and hMSH6) and MGMT, moreover 5-FU resistance than parental cell lines. Thus, although CSCs 5-FU chemoresistance appears to be independently to MMR status, hMLH1 might play a key role in CSC response to 5-FU. New drugs exploding these differences could benefit the prognostic of patients with CRC.

DNMT1 promotes cell proliferation via methylating hMLH1 and hMSH2 promoters in EGFR-mutated non-small cell lung cancer.

Aberrant DNA methylation is a common form of epigenetic alterations and it has been proved to be closely related to many cancers, while its role in epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) is not clear. This study focuses on the role of DNA methyltransferase 1 (DNMT1) in EGFR-mutated NSCLC pathogenesis. First, the expression of DNMT1 was up-regulated, while the expressions of human mutL homolog 1(hMLH1) and human mutS homolog 2 (hMSH2) were down-regulated in EGFR-mutated NSCLC patients and cell line HCC827. The results of the correlation analysis showed that DNMT1 expression was inversely correlated with the expressions of hMLH1 and hMSH2. Then, we found that DNMT1 enhanced the promoter methylation levels of hMLH1 and hMSH2, thus suppressing their expressions. DNMT1 knockdown inhibited the proliferation of HCC827 cells, while both hMLH1 knockdown and hMSH2 knockdown could eliminate its inhibitory effect on cell proliferation. In xenograft mouse models, lentiviral vector-sh-DNMT1 could significantly reduce tumor volumes, confirmed that DNMT1 inhibited tumor cell proliferation in vivo. In conclusion, DNMT1 suppressed the expressions of hMLH1 and hMSH2 via elevating their promoter methylation, thus promoting cell proliferation in EGFR-mutated NSCLC.

Association of expression of inflammatory response genes and DNA repair genes in colorectal carcinoma.

Inflammation is an important etiological factor of colorectal carcinoma and may be related to colorectal carcinoma growth and proliferation. This study aimed to verify whether the presence of chronic inflammation represented by tumor necrosis factor-α, interleukin-2, interleukin-6, and interleukin-10 gene expression is related to hMLH1, hMSH2, hMSH6, and PMS2 gene expression and the corresponding protein levels of these genes from the DNA repair system. A total of 83 patients were operated on for curative or palliative colorectal carcinoma. Expression of the inflammatory response genes tumor necrosis factor-α, interleukin-2, interleukin-6, and interleukin-10 as well as expression of the hMLH1, hMSH2, hMSH6, and PMS2 genes of the DNA repair system (mismatch repair) and the expression levels of the corresponding mismatch repair proteins were measured in neoplastic tissue by reverse transcription polymerase chain reaction and immunohistochemistry, respectively. Associations were observed between hMSH6 mRNA expression and interleukin-2 mRNA expression (p = 0.026) as well as between hMLH1 and hMSH2 gene expression and tumor necrosis factor-α gene expression (p = 0.042). Higher tissue levels of interleukin-2 and tumor necrosis factor-α gene expression were associated with lower hMSH6, hMLH1, and hMSH2 gene expression.

MLH1 promoter hypermethylation in uterine carcinosarcoma rarely coexists with TP53 mutation.

IntroductionCarcinosarcoma (CS) is an infrequent neoplasm composed of a carcinomatous and a sarcomatous element. Its molecular pathogenesis is poorly understood. In this study, we investigated the disturbances in the immunohistochemical expression of p53 and mismatch repair (MMR) proteins, as well as their molecular background.Material and methodsThe study group consisted of 20 uterine CSs. We analysed their morphology and immunohistochemical expression of hMLH1, hPMS2, hMSH2, MSH6, and p53 as well as the presence of mutations in TP53 and promoter methylation of the hMLH1. Loss of hMLH1 and PMS2 was found in 3/20 tumours. All cases were positive for hMSH2 and hMSH6. The TP53 mutation was detected in 8/19 tumours (42.1%), whereas MLH1 promoter hypermethylation in 4/19 cases (21%), and one case with synchronous aberrations (5%). Agreement between the results of the genetic and immunohistochemical study was moderate for p53 (k = 0.615, p< 0.01) and strong for MLH1 (k = 0.826, p< 0.01).Results and conclusionsWe demonstrated MLH1 promoter hypermethylation in uterine CS, leading to loss of MLH1 immunostaining. Concomitant aberrations of p53 and hMLH1 are infrequent. It is likely that uterine CS may develop in two independent molecular pathways in association with either chromosomal or microsatellite instability.

Effect of hMLH1, hMSH2, hMSH6, integrin β1, and Ki-67 expression on prognosis of colorectal cancer

Effect of hMLH1, hMSH2, hMSH6, integrin β1, and Ki-67 expression on prognosis of colorectal cancer

Culture characters, genetic background, estrogen/progesterone receptor expression, and tumorigenic activities of frequently used sixteen endometrial cancer cell lines

BackgroundThis study aimed to determine the in vitro and in vivo properties of sixteen frequently used endometrial cancer (EC) cell lines, including the cell proliferation rate, morphology, hormone receptor expression patterns, PTEN, hMLH1 expression, p53 mutation, karyotype, and tumorigenicity in mouse xenograt model. MethodsTwelve type I (AN3, ECC-1, EN, EN-1, EN-11, HEC-1A, HEC1B, Ishikawa, KLE, MFE-280, MFE-296, MFE-319) and four type II (ARK1, ARK2, HEC-155/180, SPEC-2) endometrial cancer cell lines were studied. Cell proliferation and morphology were determined using cell growth curves and light microscopy, respectively. Real-time PCR was performed to measure the mRNA levels of target genes. Denaturing High Performance Chromatography (DHPLC) screening and PCR/sequencing were performed to identify p53 mutations. G-banding was applied for karyotyping. Tumorigenicity was evaluated using mouse xenograft. ResultsThe population doubling time of the cell lines ranged between 19 and 41 h. Ishikawa, ECC-1, and MFE-280 have high while AN3 and EN1 have low expression of ER-α and ER-β. Expression of total PR and PR-B uniformly decreased in all type II cell lines and several type I cell lines (AN3, HEC-1A, HEC1B, KLE, EN-1). Regression analyses revealed significant correlations between PR-B and total PR (p < .001), between isoforms ER-α and ER-β (p < .001), and between total PR and ER (p < .001), mRNA levels in type I cell lines. p53 mutations were detected in exons 5–8 of seven out of twelve type I and one out of four type II cell lines. PTEN expression was more uniformly suppressed in type II than type I cells, while hMLH1 did not show this pattern. All the five cell lines tested contained severe karyotype abnormalities. Mouse xenograft results indicated that HEC-1A, HEC-1B and EN-1 type I as well as ARK1 and ARK2 type II cell lines had potent tumorigenic activities. Low PR-B and ER-α expression in type I cell lines were associated with high tumorigenic activity. ConclusionsThis study provides resource information on EC cell lines commonly used in laboratories, which could be used for choosing cell lines suitable for specific research purposes. The results of karyotype analysis and p53 mutation together with hormone receptor expression pattern and morphology comparison strongly suggested an independent nature of these cell lines, excluding the possibility of cross-contamination between cell lines.Additionally, this information suggests potential directions for future studies on the pathogenic mechanisms of endometrial cancer.

Abstract 5227: Suppressive role of elevated estrogen on endometrial carcinogenesis

Abstract Background: Although estrogen has been regarded as a risk factor for endometrial carcinoma, its concentration-dependent carcinogenetic effects remain unclear, because most endometrial carcinomas occur in post-menopausal women, whose serum estrogen levels are relatively low. Because impaired mismatch repair (MMR) was reportedly crucial in the early stages of endometrial carcinogenesis, we focused on the relationship between various estrogen concentration and MMR activity in normal and malignant endometrial glandular cells. In those cells, we reported that the protein and mRNA expression of both hMLH1 and hMSH2, the key factors of MMR, were up-regulated by estrogen stimulation. In addition, we demonstrated that the estrogen stimulation enhanced the MMR activity in those cells using in vitro MMR assay with the M13mp2 phage heteroduplex DNAs and that the proliferating cells without hMLH1/hMSH2 expressions implying “high risk” cells were more frequently observed under relative-low estrogen concentrations. In this study, to further confirm the role of E2 in vivo, we employed a mouse endometrial carcinoma model induced by intra-uterine injection of a carcinogen, N-methyl-N-nitrosourea (MNU) under various E2 concentrations. Methods: MNU was injected into the uterine cavity of 29 CD-1 mice at 6 weeks of age, and E2 was administered by pellets or orally. Uteri were removed for histological examinations 24 weeks later, and serum E2 levels were measured. The immunohistochemical expression of MMR proteins in uterine epithelia was investigated. Results: Of 29 mice, 8, 8, 8, and 5 showed atrophic, normal, hyperplastic, and carcinomatous endometria, respectively. The mean E2 levels of each group were 0.2pg/ml, 3.8pg/ml, 190.0pg/ml, and 6.7pg/ml, with significant differences. The expression of the MMR proteins was stronger in mice with elevated E2. Conclusions: Elevated E2 levels preferentially induced endometrial hyperplasia rather than carcinoma, and this may be mediated by MMR proteins. These results indicate that modest E2 is needed, whereas elevated E2 levels are not necessarily advantageous for carcinogenesis, suggesting the importance of low-chronic (un-opposed) estrogen in human endometrial carcinogenesis. Citation Format: Ryoichi Asaka, Tsutomu Miyamoto, Koichi Ida, Hodaka Takeuchi, Hirofumi Ando, Yasushi Yamada, David Hamisi Mvunta, Hisanori Kobara, Hiroyasu Kashima, Tanri Shiozawa. Suppressive role of elevated estrogen on endometrial carcinogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5227.

Clinical significance of chromodomain helicase/ATPase DNA binding protein 1-like and human mutL homolog 1 gene expression in cholangiocarcinoma.

Cholangiocarcinoma is a highly malignant form of gastrointestinal cancer with an unfavorable prognosis. The novel oncogene chromodomain helicase/ATPase DNA binding protein 1-like (CHD1L) has been confirmed to serve a vital role in numerous types of cancer, including liver cancer. Mismatch repair (MMR) is a common DNA repair process that contributes to the preservation of the integrity and stability of genetic substances. Human mutL homolog 1 gene (hMLH1) is an important MMR protein family member. The present study aimed to evaluate the pathological and clinical features of cholangiocarcinoma, and to investigate the clinical significance of CHD1L and hMLH1 expression in cholangiocarcinoma. A total of 108 samples from cholangiocarcinoma tumor tissues and 60 samples from normal bile duct tissue were obtained from patients admitted to The Second Affiliated Hospital of Nanchang University between May 2005 and May 2014. All cholangiocarcinoma cases were pathologically confirmed. The expression of CHD1L and hMLH1 was examined by immunohistochemistry analysis. The expression of CHD1L in cholangiocarcinoma (94.44%) was significantly higher than in normal bile duct tissues (40.00%). CHD1L expression was associated with gallstone history, serum carbohydrate antigen 19-9 (CA19-9) level and Tumor-Node-Metastasis (TNM) stage (P<0.05). hMLH1 expression in cholangiocarcinoma (77.78%) was significantly lower than in normal bile duct tissues (96.67%), and was associated with gender, age, serum CA19-9 level, the presence of hepatitis B virus surface antigen, TNM stage and tumor diameter (P<0.05). Kaplan-Meier survival curve analysis indicated that the 3-year accumulative survival rates for CHD1L-positive and -negative patients differed significantly (P<0.05; 17.90 and 83.33%, respectively). There was no statistically significant difference (P>0.05) between the 3-year accumulate survival rates for hMLH1-positive and -negative patients (38.90 and 33.30%, respectively). High CHD1L expression and low hMLH1 expression levels were observed in patients with cholangiocarcinoma, and their abnormal expression patterns were associated with the progression of malignancy and an unfavorable disease prognosis. Therefore, CHD1L and hMLH1 may be potential prognostic biomarkers for cholangiocarcinoma.

The G2 phase arrest induced by sterigmatocystin is dependent on hMLH1- ERK/p38-p53 pathway in human esophageal epithelium cells in vitro

Sterigmatocystin (ST), being a precursor of aflatoxin, is categorized as Group 2B carcinogen. Our previous studies found that both mismatch repair (MMR) pathways and p53 signaling pathway were involved in ST-induced G2 cell cycle arrest in human esophageal squamous epithelial cell line, HET-1A, in vitro. Studies showed that ERK, JNK and p38 signaling pathways played important roles in cell cycle arrest induced by several other carcinogens. However, the role of MAPK pathway and the links between the MMR and p53 signaling pathways in ST induced G2 phase arrest is still not clarified. In the present study, we first explored the role of MAPK pathway upon ST induced G2 arrest, and found that ST up-regulated the expression of G2/M regulatory factors through MAPK signaling pathway (both ERK and p38, but not JNK pathway). The inhibition of ERK and p38 significantly inhibited p53 activation by ST. Blockage of MMR pathway by silencing hMLH1 expression inhibited ERK, p38 and p53 activation and then attenuated G2 arrest by ST. Thus, in conclusion, the current study demonstrated that in response to ST induced DNA damage, hMLH1 was first activated, then triggered ERK, p38 and p53 activation and finally resulted in G2 arrest in HET-1A cells.

Expression of hMLH1 and hMSH2 proteins in ameloblastomas and tooth germs.

BackgroundMismatch repair proteins (MMRPs) are a group of nuclear enzymes that participate in the repair of base mismatches that occur during DNA replication in all proliferating cells. The most studied MMRPs are hMSH2 and hMLH1, which are known to be highly expressed in normal tissues. A loss of MMRPs leads to the accumulation of DNA replication errors in proliferating cells. Ki-67 is a biomarker regarded to be the gold-standard tool for determining cell proliferation by immunohistochemical methods. The aim of this study was to investigate the immunohistochemical expression of hMLH1, hMSH2 and Ki-67 proteins in ameloblastomas and tooth germs, to contribute to the understanding of the development of this odontogenic neoplasm.Material and MethodsImmunohistochemical assays to determine the presence of proteins hMSH2, hMLH1 and Ki-67 were performed in 80 ameloblastomas (40 solid and 40 unicystic) and five tooth germs.ResultsUnicystic ameloblastomas showed higher MMRP expression (hMLH1: 62.5 ± 43.4; hMSH2: 83.3 ± 47.8) than did solid ameloblastomas (hMLH1: 59.4 ± 13.5; hMSH2: 75.8 ± 40.2). Additionally, the cell proliferation index assessed by Ki-67 was inversely proportional to the expression of MMRP. Comparison between tooth germs and ameloblastoma revealed significantly higher expression of hMLH1, hMSH2 and Ki-67 in tooth germs (p=0.02).ConclusionsThe differences of MMRP and Ki-67 immunoexpression between ameloblastomas and tooth germ suggest that alterations in the MMRP mechanisms could participate in the biological behavior of ameloblastomas. Key words:hMLH1, hMSH2, Ki-67, Ameloblastomas, Tooth germs.

RG108 induces the apoptosis of endometrial cancer Ishikawa cell lines by inhibiting the expression of DNMT3B and demethylation of HMLH1.

The effects of DNA methyltransferase (DNMT) inhibitor RG108 on the proliferation and apoptosis of endometrial cancer was investigated, and whether its mechanism was related to the inhibition of DNMT3B, thereby affecting the human mutL homolog 1 (hMLH1) methylation status and its expression, was further studied. Culture of human endometrial cancer Ishikawa cell lines: cells grew adhering to the wall in Roswell Park Memorial Institute-1640 (RPMI-1640) medium (supplemented with 10% fetal bovine serum (FBS) and 2 mM L-glutamic acid). After the cells were treated with RG108, the changes in cell viability were detected via methyl thiazolyl tetrazolium (MTT) assay. The effect of RG108 on cell cycle was detected via flow cytometry, and its effect on cell apoptosis was detected via flow cytometry and TUNEL. Moreover, the methylation status of hMLH1gene in endometrial cancer cells was detected via methylation specific-PCR (MSP), and the changes in DNMT3Band hMLH1 expressions were detected via RT-PCR and Western blotting, respectively. MTT results showed that RG108 inhibited the cell viability in a dose-dependent and time-dependent manner. Flow cytometry revealed that RG108 blocked the cell cycle in G2/M phase and promoted the apoptosis, and TUNEL assay further proved that RG108 promoted the apoptosis. It was found in the detection via MSP that the methylated hMLH1 gene was significantly reduced after 72 h of treatment with RG108. Besides, RT-PCR and Western blotting showed that RG108 inhibited the DNMT3B expression and activated the hMLH1 expression. The demethylation drug RG108 can significantly inhibit the proliferation of endometrial cancer cells, block the cell cycle in the G2/M phase and induce the cell apoptosis, which is a new candidate drug in the treatment of endometrial cancer. RG108 realizes the hMLH1 demethylation and increases the hMLH1 expression through inhibiting the expression of DNMT3B.

Distinct histopathological characteristics in colorectal submucosal invasive carcinoma arising in sessile serrated adenoma/polyp and conventional tubular adenoma.

The histopathological characteristics of colorectal submucosal invasive carcinoma arising in sessile serrated adenoma/polyp (SSA/P), a rare malignant tumour, have not yet been fully elucidated. To investigate the features of such, we retrospectively analysed 40 submucosal invasive carcinomas with SSA/P (CA-SSA/P) and compared them to 129 cases of submucosal invasive carcinoma with conventional tubular adenoma (CA-AD). We additionally performed hMLH1 immunostaining. CA-SSA/Ps were significantly smaller than CA-ADs (P<0.001). Histologically, well to moderately differentiated adenocarcinoma was predominant in both CA-SSA/Ps and CA-ADs. No significant differences in depth of invasion were found between the two groups. However, lymphatic invasion was more often found in CA-SSA/Ps (30%) than in CA-ADs (13%; P=0.028), as was lymph node metastasis (CA-SSA/Ps, 28%; CA-ADs, 7%; P=0.011). Furthermore, mucinous component and serrated architecture were significantly more frequent in CA-SSA/Ps (30 and 63%) than in CA-ADs (5 and 18%; P<0.001, respectively). Tumour-infiltrating lymphocytes and Crohn-like inflammatory reaction were also more frequently found in CA-SSA/Ps (70 and 30%) than in CA-ADs (31 and 9%; P≤0.001, respectively), whereas the opposite was true of desmoplastic reaction (CA-SSA/Ps, 35%; CA-ADs, 67%; P<0.001). Loss of hMLH1 expression was more frequent in CA-SSA/P cases (93%) than in CA-AD cases (5%; P<0.001). In conclusion, CA-SSA/P lesions exhibit a higher potential for lymphatic invasion and lymph node metastasis and have distinct histopathological features, including mucinous component, serrated architecture, tumour-infiltrating lymphocytes, Crohn-like inflammatory reaction, and absence of desmoplastic reaction, compared to their conventional counterparts.

Comparison between mononucleotide and dinucleotide marker panels in gastric cancer with loss of hMLH1 or hMSH2 expression.

DNA mismatch repair deficiency is an important molecular mechanism of genetic instability in gastric cancer, and a high instability at microsatellites is associated with favorable prognosis. We compared mononucleotide and dinucleotide microsatellite instability (MSI) marker panels in 56 paired gastric tumor and normal samples. The mononucleotide marker panel (mono panel) consisted of 8 markers: BAT25, BAT26, BAT40, BAT-RII, NR21, NR22, NR24 and NR27. The dinucleotide marker panel (di panel) contained D2S123, D5S346, D17S250, D17S261, D17S520, D18S34 and D18S58. The NCI panel was used as reference panel. Among 13 gastric tumors showing no hMLH1 or hMSH2 expression, 8 MSI-H (high) and 5 MSI-L (low) were identified. The analytical sensitivities of the NCI, mono and di panels to detect unstable MSI were 61.5% (8/13), 76.9% (10/13) and 84.6% (11/13), respectively. The size change of allele shift was statistically greater in the mono panel than in the di panel (p = 0.02 by Mann-Whitney U-test). The BAT40 (69.2%, 9/13) and D18S34 (76.9%, 10/13) markers showed high sensitivity for determination of MSI status. To improve the detection rate of MSI in gastric cancer with loss of hMLH1 or hMSH2 expression, the kind of MSI marker may need to be considered more, instead of the repetitive type of marker. Thus, an MSI panel designed with a combination of both BAT40 and D18S34 is suggested for providing more accurate and sensitive MSI analysis in gastric cancer.

Association between promoter methylation and protein expression of tumor suppressor genes with clinical characteristics in gastric carcinoma and its effect on the biological function of gastric cancer.

e15509 Background: Studies showed that the gene promoter methylation may be the third important mechanisms of gene expression regulation. Abnormal methylation of tumor suppressor gene can be detected in the early stage of tumor, by screening the methylation profile of gastric cancer (GC), it can provide theoretical and experimental evidence for early diagnosis, treatment and prognosis. Methods: Detecte p16, hMLH1 and CDH1 promoter methylation, the p16, hMLH1 and E-cadher expression in GC tissues and its correlation with clinicopathological features and prognosis. Detect methylation of hMLH1 promoter and mRNA expression in GC cell line and normal gastric mucosa cell line. Clone formation assay and Transwell test. Results: The methylation of hMLH1 and CDH1 in GC and adjacent tissues were statistically significant . The methylation of hMLH1 was related to alcohol , CA199 level and Borrman. The methylation of CDH1 was related to the CEA level. The methylation of hMLH1 promoter is related to OS in GC patients. The methylation of p16 and CDH1 was not related to the OS ofGC patients. The GC patients with 0 or 1 gene methylation had a better prognosis than those with 3 or 2 gene methylation. The p16, hMLH1 and E-cadherin protein expression in GC and adjacent tissues were statistically significant. The p16 protein expression was related to tumor size. The hMLH1 protein expression was related to the CA199 level and tumor size. The E-cadherin expression in GC patients with drinking history was lower than ones without drinking history. The p16, hMLH1 and E-cadherin protein expression was not related to the OS of GC patients. There was a negative correlation between hMLH1 gene methylation and its protein expression in GC. The number of clones in the control group and the experimental group were 180 ± 3 and 169 ± 6. The number of cells in the control group and the experimental group were 135 ± 4.08 and 125 ± 4.18. Conclusions: The methylation of multiple genes is associated with the prognosis, which can provide theoretical basis for accurate treatment and prognosis for GC patients.

Epidermal growth factor receptor and epididymis invasion as prognostic biomarkers in clinical stage I testicular germ cell tumours

BackgroundInguinal orchiectomy is curative in 70–80% of clinical stage I testicular germ cell tumours (CS I TGCT). The identification of patients who are at low risk of relapse is critical to avoid unnecessary treatment. The aim of this study is to explore EGFR, hMLH-1/hMSH-2 and microsatellite instability (MSI) as potential prognostic factors of recurrence in CS I TGCT.MethodsFifty-six CS I TGCT patients who underwent inguinal orchiectomy were included in this study. We analysed the relationship between clinicopathological and molecular factors with survival. Analysis of hMLH1, hMSH2 and EGFR expression was carried out by immunohistochemistry. Methylation status of the hMLH1 promoter was determined by pyrosequencing analysis in selected cases. EGFR exons 19, 20, 21 were analysed by PCR labeled-fragments and MSI status was determined using standard Multiplex MSI assays.ResultsClassical pathological factors such as lymphovascular invasion, high percentage of embryonal carcinoma, rete testis invasion or tumour size ≥4 cm showed a significant relationship with a higher risk of relapse. Additionally, it was found that an epididymis invasion proved to be a significant independent poor prognostic factor of recurrence (p = 0.001). hMLH1 or hMSH2 expression showed no significant association with risk of relapse and no MSI was found. EGFR expression was observed in 30.4% of samples and its expression was associated with higher risk of relapse (HR 3.5; 95% CI 1.3–9.8; p = 0.016). None of the cases presented EGFR kinase domain mutations.ConclusionsEpididymis invasion and EGFR expression, but not hMLH-1/hMSH-2 or MSI, could be potentially useful as new prognostic factors of recurrence for CS I TGCT.

Differential Expression and Clinical Significance of DNA Methyltransferase 3B (DNMT3B), Phosphatase and Tensin Homolog (PTEN) and Human MutL Homologs 1 (hMLH1) in Endometrial Carcinomas.

BackgroundThe aim of this study was to investigate the expression and the clinicopathologic significance of DNA methyltransferase 3B (DNMT3B), phosphatase and tensin homolog (PTEN) and human MutL homologs 1 (hMLH1) in endometrial carcinomas between Han and Uygur women in Xinjiang.Material/MethodsThe expression of DNMT3B, PTEN, and hMLH1 in endometrial carcinomas were assessed by immunohistochemistry, followed by an analysis of their relationship to clinical-pathological features and prognosis.ResultsThere were a 61.7% (95/154) overexpression of DNMT3B, 50.0% (77/154) loss of PTEN expression and 18.2% (28/154) loss of hMLH1 expression. The expression of DNMT3B and PTEN in endometrial carcinomas was statistically significantly different between Uygur women and Han women (p=0.001, p=0.010, respectively). DNMT3B expression was statistically significant based on the grade of endometrial carcinomas (p=0.031). PTEN loss was statistically significant between endometrioid carcinomas (ECs) and non endometrioid carcinomas (NECs) (p=0.040). DNMT3B expression was statistically significant in different myometrial invasion groups in Uygur women (p=0.010). Furthermore, the correlation of DNMT3B and PTEN expression was significant in endometrial carcinomas (p=0.021). PTEN expression was statistically significant in the overall survival (OS) rate of women with endometrial cancers (p=0.041).ConclusionsOur findings suggest that PTEN and DNMT3B possess common regulation features as well as certain ethnic differences in expression between Han women and Uygur women. An interaction may exist in the pathogenesis of endometrial carcinoma. DNMT3B was expressed differently in cases of myometrial invasion and PTEN was associated with OS, which suggested that these molecular markers may be useful in the evaluation of the biological behavior of endometrial carcinomas and may be useful indicators of prognosis in women with endometrial carcinomas.

Deficiency of hMLH1 and hMSH2 expression is a poor prognostic factor in Early Gastric Cancer (EGC).

Purpose: The aim of the study was to investigate the effect of deficiency of hMLH1 and hMSH2 expression on the prognosis of early gastric cancer (EGC) in Chinese populations.Methods: A total of 160 EGC patients who underwent curative gastrectomy with lymphadenectomy from January 2011 to July 2014 at Xinhua Hospital were evaluated. The expression rates of hMLH1 and hMSH2 were examined using tissues preserved in paraffin blocks by immunohistochemical staining. The clinicopathological characteristics and prognosis of EGC with deficient hMLH1 and hMSH2 were analyzed.Results: On immunohistochemical staining, the loss expression of hMLH1 and hMSH2 were observed in 89 (55.6%) and 45 (28.1%), respectively. The hMLH1 deficiency was associated with the middle third of tumor location (P = 0.041). According to Kaplan-Meier survival analysis and Log-Rank test, the loss expression of hMLH1 and hMSH2 were associated with worse survival than positive hMLH1 (HR = 0.247, 95% CI = 0.078-0.781, P = 0.017) and hMSH2 (HR = 0.174, 95% CI = 0.051-0.601, P = 0.006) in EGC.Conclusion: The main conclusions were as follows: The hMLH1 deficiency was preferred to the middle third of EGC. Lymph node metastasis (LNM) was a prognostic factor of EGC. And the prognosis of EGC patients with deficient mismatch repair (dMMR, mainly including deficient hMLH1 and hMSH2) was obviously worse than proficient mismatch repair (pMMR).