Mutational activation of Ras and a key downstream effector of Ras, the B-Raf serine/threonine kinase, has been observed in melanomas and colorectal carcinomas. These observations suggest that inhibition of B-Raf activation of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase kinase (MEK) and the extracellular signal-regulated kinase MAPK cascade may be an effective a...

BACKGROUND The frequency of colorectal adenomas and carcinomas was investigated in a large cohort of women with breast cancer in comparison with matched controls, since data on the occurrence of second tumors in women with breast cancer is controversial. DESIGN In a cohort study, 188 consecutive women (median age 57 years) with primary breast cancer and 376 age-matched women who served as con...

We have previously observed that the frequency of loss of heterozygosity (LOH) on chromosome 18q was low in adenomas and intramucosal carcinomas, whereas invasive carcinomas exhibited a high frequency in familial adenomatous polyposis patients (M. Miyaki et al., Cancer Res., 50: 7166-7173, 1990). In the present study, LOH at the DCC locus on chromosome 18q and the expression of DCC gene into mR...

Colorectal cancer often arises from adenomatous colonic polyps. Polyps can grow and progress to cancer, but may also remain static in size, regress, or resolve. Predicting which polyps progress and which remain benign is difficult. We developed a novel long-lived murine model of colorectal cancer with tumors that can be followed by colonoscopy. Our aim was to assess whether these tumors have si...

BACKGROUND Human X-box binding protein 1 (XBP-1) is a transcription factor essential for hepatocyte growth, as well as for plasma cell differentiation. Recently, overexpression of XBP-1 has been reported in breast cancer including non-invasive carcinomas, and was suggested to play an important role in breast carcinogenesis. To investigate the involvement of XBP-1 in colorectal tumorigenecity, t...

Genomic instability and epigenetic aberrations are important classifiers of human tumors, yet, their interrelations are poorly understood. We used Lynch syndrome (LS) to address such relationships. Forty-five tumors (11 colorectal adenomas, 18 colorectal carcinomas, and 16 ovarian carcinomas) were profiled for CpG Island Methylator Phenotype (CIMP) and somatic mutations. All tumors showed high-...

BACKGROUND Homeodomein only protein x (HOPX) gene methylation has frequently been detected in cancer tissues. The methylation status of the HOPX gene in colorectal cancer was examined and compared to the clinocopathological findings. MATERIALS AND METHODS Eighty-nine tumor samples and corresponding normal tissues were obtained from colorectal cancer patients who underwent surgery at our hospi...

BACKGROUND/AIMS This study had three aims. The first was to determine whether Bax (Bcl-2-associated X protein) and AIF (apoptosis-inducing factor) are expressed in tissue sections of colorectal tumors. The second was to ascertain whether there is any difference in Bax and AIF expression between colorectal polyps, adenomas, and carcinomas. The third aim was to determine whether there is any diff...

All human cells are covered by glycans, the carbohydrate units of glycoproteins, glycolipids, and proteoglycans. Most glycans are localized to cell surfaces and participate in events essential for cell viability and function. Glycosylation evolves during carcinogenesis, and therefore carcinoma-related glycan structures are potential cancer biomarkers. Colorectal cancer is one of the world's thr...