Mitsuharu Nomoto

MUC2 gene expression is found in noninvasive tumors but not in invasive tumors of the pancreas and liver: Its close relationship with prognosis of the patients☆

We have previously reported that MUC2 apomucin was highly expressed in noninvasive tumors of the pancreas (intraductal papillary tumor [IdPT]) and liver (bile duct cystadenocarcinoma [BdCC]), which show more favorable outcomes than invasive carcinomas. In contrast, MUC2 was rarely expressed in invasive carcinomas of the pancreas (invasive ductal carcinoma [IDC]) and the liver (invasive cholangiocarcinoma [ICC]). In the present study, we examined localization of MUC2 messenger RNA (MUC2 mRNA) by using a complementary DNA (cDNA) probe for the MUC2 tandem repeat for in situ hybridization (pHAM1). Localization of MUC2 apomucin was determined by using an antibody directed against MUC2 apomucin (anti-MRP) for immunohistochemistry study. Eleven IdPTs and 10 IDCs of the pancreas, and 8 BdCC and 8 ICCs of the liver were examined. Nine (82%) of 11 IdPTs showed positive expression of MUC2 mRNA in the neoplastic cells, whereas none (0%) of the IDCs showed expression of MUC2 mRNA. Six (75%) of the 8 BdCCs showed positive expression of MUC2 mRNA in the neoplastic cells, whereas none (0%) of the 8 ICCs showed expression of MUC2 mRNA. The localization of MUC2 mRNA and that of MUC2 apomucin usually coincided, although a few cases (1 IDC, 1 BdCC, and 1 ICC) showed focal expression of MUC2 apomucin despite the absence of detectable MUC2 mRNA. These results indicate that the expression of MUC2 apomucin in IdPTs and BdCCs correlates with expression of MUC2 mRNA. In both patient groups with pancreatic tumors and hepatic tumors, patients with positive MUC2 mRNA expression in the tumors showed significantly better survival than those with negative MUC2 mRNA expression in the tumors. The production of MUC2, an abundant extracellular mucin, by most IdPTs and BdCCs may be correlated with tumors that display lower levels of invasion and metastasis.

Expression profiles of MUC1, MUC2, and MUC4 mucins in human neoplasms and their relationship with biological behavior.

Mucins are high molecular weight glycoproteins that play important roles in carcinogenesis or tumor invasion. To clarify the relationship of the expression patterns of mucins in human neoplasms with their biological behavior, we examined the expression profiles of MUC1, MUC2, and MUC4 mucins in various human neoplasms using immunohistochemistry and in situ hybridization, and compared them with clinicopathologic factors including outcome of the patients. MUC1 or MUC4 expression is related with the aggressive behavior of human neoplasms and a poor outcome of the patients. In contrast, MUC2 expression tends to be related with the indolent behavior of human neoplasms and a favorable outcome of the patients, although indolent pancreatobiliary neoplasms sometimes show invasive growth with MUC1 expression in the invasive areas. The expression of MUC2 mucin in indolent pancreatobiliary neoplasms coincided with expression of MUC2 mRNA. Our recent studies to clarify the MUC2 gene regulation mechanism disclosed that DNA methylation and histone modification in the 5′ flanking region of the MUC2 promoter may play an important role. Further studies of the epigenetics also in MUC1 and MUC4 gene expression may be needed to understand the relationship between the expression of mucins in human neoplasms with their biological behavior.

Expression of mucins (MUC1, MUC2, MUC5AC and MUC6) in mucinous carcinoma of the breast: comparison with invasive ductal carcinoma

Aims:  Mucinous carcinoma of the breast usually shows less frequent lymph node metastasis and more favourable outcome compared with invasive ductal carcinoma. The aim of this study is to compare the expression profiles of several mucins in mucinous carcinomas and invasive ductal carcinomas to gain insight into the relationship between the less aggressive biological nature of mucinous carcinoma and the role of mucins.

Expression of MUC1 and MUC2 mucins in extrahepatic bile duct carcinomas: Its relationship with tumor progression and prognosis

Our previous immunohistochemical studies in the pancreas, intrahepatic bile duct, and ampulla of Vater demonstrated that an invasive carcinoma with a poor outcome showed a pattern of MUC1 (membrane‐bound mucin) positive and MUC2 (intestinal‐type secretory mucin) negative, whereas many of the non‐invasive tumors with favorable outcome showed a pattern of MUC1 negative and MUC2 positive. The aim of this study is to compare the expression profiles of MUC1 and MUC2 mucins in extrahepatic bile duct carcinomas to gain insight into the relationship between the biological nature of the carcinomas and the role of mucins. We examined the expression profiles of MUC1 of different glycoforms and MUC2 in 60 extrahepatic bile duct carcinomas using immunohistochemistry. The expression of MUC1/CORE (core peptide of MUC1), MUC1/DF3 (core peptide of MUC1 with sialyl oligosaccharides) and MUC1/MY.1E12 (sialylated MUC1) showed a significant relationship with tumor progression factors such as poor differentiation, deep invasion, lymph node metastasis, lymphatic invasion or perineural invasion. In contrast, the expression of MUC1/HMFG‐1 (fully glycosylated MUC1) did not show a significant relationship with the tumor progression factors. In the different glycoforms of MUC1 examined, the expression of MUC1/DF3 and MUC1/MY.1E12 was related with the poor outcome of the patients. In contrast, the expression of MUC2 was inversely related with the tumor progression factors and poor outcome. In the 52 patients with advanced tumors, only MUC1/DF3 high expression correlated with poor prognosis. In conclusion, MUC1/DF3 was the most useful prognosis indicator among the various glycoforms of MUC1 mucins.

A micropapillary pattern is predictive of a poor prognosis in lung adenocarcinoma, and reduced surfactant apoprotein A expression in the micropapillary pattern is an excellent indicator of a poor prognosis

A micropapillary pattern is defined as papillary tufts without a fibrovascular core and is known to be a factor that indicates a poor prognosis in numerous cancers. However, their role in lung adenocarcinoma has not been investigated widely. In 185 cases of small-size lung adenocarcinoma (≤3 cm), cases with a micropapillary pattern ratio of more than 1% (analyzed by NIH image) were defined as micropapillary pattern positive. Correlations between the micropapillary pattern and clinicopathological factors were investigated and immunohistochemical expression of mucin and various antigens was examined in regions with and without micropapillary patterns. Micropapillary pattern-positive tumors (micropapillary pattern ratio ≥1%) were observed in 11.4% of cases (21/185) and the micropapillary pattern ratio correlated with TNM stage (P=0.0002), lymphatic invasion (P=0.0002) and lymph node metastasis (P=0.03). Disease-free interval (P<0.0002) and survival (P=0.027) were significantly shorter for micropapillary pattern-positive patients, and micropapillary pattern-positive stage IA cases also had a significantly shorter disease-free interval (P<0.0001). MUC1 was expressed strongly across the surface of the micropapillary structure, whereas MUC4 tended to show lower expression in the micropapillary pattern. It was noteworthy that the disease-free interval in patients with high surfactant apoprotein A expression was significantly better than in patients with low surfactant apoprotein A expression (P=0.03), and no recurrence or death occurred in patients with high surfactant apoprotein A expression. Our results show that the micropapillary pattern ratio correlates with lymphatic invasion and lymph node metastasis, and that a high micropapillary pattern ratio leads to a poor prognosis. High MUC1 expression on the surface is an important characteristic of a micropapillary pattern, and reduced surfactant apoprotein A expression in the micropapillary pattern may be an excellent indicator for poor prognosis in small-size lung adenocarcinoma.

MUC2 expression is regulated by histone H3 modification and DNA methylation in pancreatic cancer

Mucins are highly glycosylated proteins that play important roles in carcinogenesis. In pancreatic neoplasia, MUC2 mucin has been demonstrated as a tumor suppressor and we have reported that MUC2 is a favorable prognostic factor. Regulation of MUC2 gene expression is known to be controlled by DNA methylation, but the role of histone modification for MUC2 gene expression has yet to be clarified. Herein, we provide the first report that the histone H3 modification of the MUC2 promoter region regulates MUC2 gene expression. To investigate the histone modification and DNA methylation of the promoter region of the MUC2 gene, we treated 2 human pancreatic cancer cell lines, PANC1 (MUC2‐negative) and BxPC3 (MUC2‐positive) with the DNA methyltransferase inhibitor 5‐azacytidine (5‐aza), the histone deacetylase inhibitor trichostatin A (TSA), and a combination of these agents. The DNA methylation level of PANC1 cells was decreased by all 3 treatments, whereas histone H3‐K4/K9 methylation and H3‐K9/K27 acetylation in PANC1 cells was changed to the level in BxPC3 cells by treatment with TSA alone and with the 5‐aza/TSA combination. The expression level of MUC2 mRNA in PANC1 cells exhibited a definite increase when treated with TSA and 5‐aza/TSA, whereas 5‐aza alone induced only a slight increase. Our results suggest that histone H3 modification in the 5′ flanking region play an important role in MUC2 gene expression, possibly affecting DNA methylation. An understanding of these intimately correlated epigenetic changes may be of importance for predicting the outcome of patients with pancreatic neoplasms.

Promoter CpG methylation in cancer cells contributes to the regulation of MUC4

Mucin 4 (MUC4) is a high molecular weight transmembrane mucin that is overexpressed in many carcinomas and is a risk factor associated with a poor prognosis. In this study, we show that the DNA methylation pattern is intimately correlated with MUC4 expression in breast, lung, pancreas and colon cancer cell lines. We mapped the DNA methylation status of 94 CpG sites from −3622 to +29 using MassARRAY analysis that utilises base-specific cleavage of nucleic acids. MUC4-negative cancer cell lines and those with low MUC4 expression (eg, A427) were highly methylated near the transcriptional start site, whereas MUC4-positive cell lines (eg, NCI-H292) had low methylation levels. Moreover, 5-aza-2′-deoxycytidine and trichostatin A treatment of MUC4-negative cells or those with low MUC4 expression caused elevation of MUC4 mRNA. Our results suggest that DNA methylation in the 5′ flanking region play an important role in MUC4 gene expression in carcinomas of various organs. An understanding of epigenetic changes in MUC4 may contribute to the diagnosis of carcinogenic risk and prediction of outcome in patients with cancer.

Uterine lipoleiomyoma: A histopathological review of 17 cases

Lipoleiomyoma is a rare uterine tumor. The exact frequency and proliferation activity are not yet known. This study aims to know the frequency and evaluate the relation with renal angiomyolipoma. Lipoleiomyoma cases were immunohistochemically stained by antibodies for Ki‐67, melanoma specific antigen HMB45, S‐100 protein, and α smooth muscle actin (α‐SMA). Frequency of uterine lipoleiomyoma among  uterine  myomatous  tumor  was  17/4904  (0.35%)  in the Department of Human Pathology, Field of Oncology, Kagoshima University Graduate School database (1983–2003). Patients ranged from 45 to 74 years of age, and 10 cases were associated with leiomyoma. Six of 17 (35%) cases showed areas with renal angiomyolipoma‐like vessels and atypical cellular features. Immunostaining was available in 12 cases. By Ki‐67 labeling index, both muscle (average 1.38%) and fat (average 1.17%) portions of the tumor had greater proliferation than normal myometrium (average 0.76%), which suggests that fat portions of the tumor are proliferating adipose tissue rather than fatty degeneration of muscular counterpart. HMB45 antigen, which is positive in renal angiomyolipoma, was negative in three uterine cases having angiomyolipoma‐like vessels (3/12). However, HMB45 antigen was positive in spindle‐shaped tumor cells of three cases (3/12) which lacked angiomyolipoma‐like vessels. Presence of angiomyolipoma‐like blood vessels in these tumors is not an uncommon feature. However, the diagnosis of uterine angiomyolipoma should not be based on the result of HMB45 antigen immunoreactivity alone.

FDG PET/CT and diffusion-weighted imaging of head and neck squamous cell carcinoma: comparison of prognostic significance between primary tumor standardized uptake value and apparent diffusion coefficient.

Purpose: To compare primary tumor 18F-fluorodeoxyglucose (FDG) maximum standardized uptake value (SUVmax) and diffusion-weighted imaging (DWI) apparent diffusion coefficient (ADC) obtained in the same patients with head and neck squamous cell carcinoma (HNSCC) to clarify the prognostic significance of both indexes. Materials and Methods: The study population comprised 26 patients with HNSCC visible on both pretreatment FDG PET/CT and DWI. Correlation between SUVmax and ADC (b values; 0 and 800 seconds/mm2) was analyzed by the Spearmans rank test. Disease-free survival (DFS) was calculated by the Kaplan-Meier method. Prognostic significance was assessed by the long-rank test and Cox proportional hazards analysis. Results: SUVmax and ADC correlated significantly and negatively (&rgr; = −0.566, P = 0.005). High (>12.1) SUVmax (P < 0.001), low (⩽0.88) ADC (P = 0.009), high (T3–4) T stage (P = 0.030), and high (N2–3) N stage (P = 0.007) were significant in predicting poor 2-year DFS. The accuracy for predicting disease events was 81% (21/26) for SUVmax (>12.1) and 73% (19/26) for ADC(⩽0.88) without significant difference between them (P = 0.52). Disease event hazards ratios for significant unadjusted SUVmax (P = 0.015) and ADC (P = 0.039) remained significant when adjusted for other dichotomized clinical covariates (SUVmax; P = 0.009–0.039, ADC; P = 0.017–0.037) except SUVmax for ADC and ADC for SUVmax and T stage. Conclusion: These results suggest that pretreatment primary tumor SUVmax and ADC correlate significantly and negatively and both may have similar potential to predict DFS or disease events of HNSCC.

Polymorphisms of the CYP1B1 gene as risk factors for human renal cell cancer.

Purpose: CYP1B1 activates various environmental carcinogens in human tissues, including renal tissues. We hypothesize that certain polymorphisms of the CYP1B1 gene are risk factors for renal cell cancer. The rationale for this hypothesis is that chemical procarcinogenic compounds require metabolic activation by oxidative enzymes such as CYP1B1 to be transformed into potentially carcinogenic forms. To test this hypothesis, we investigated the genotypic distributions of six different loci on the CYP1B1 gene and their association with renal cell cancer. Experimental Design: DNA from 211 cases of human renal cell cancer and 200 healthy controls was analyzed by sequence-specific PCR and direct DNA sequencing to determine the genotypic frequencies of six different polymorphic loci on the CYP1B1 gene. Results: The results of this study demonstrate that the frequencies of genotype 119T/T and genotype 432G/G were significantly higher in renal cell cancer patients compared with healthy normal controls. The relative risks were calculated as 3.01 and 2.17 for genotypes 119T/T and 432G/G, respectively, in renal cell carcinoma patients. These genotypic distributions were also significantly different between male and female patients. The relative risks of genotype 119T/T were calculated as 3.95 in males and 1.92 in females, and the relative risks of genotype 432G/G were calculated as 2.81 in males and 1.35 in females. Conclusions: The present study demonstrates for the first time that the polymorphisms at codons 119 and 432 may be risk factors for renal cancer, especially in the male population.