The aim of our study was to assess the relationship between colorectal tumor responsiveness to irinotecan and microsatellite instability (MSI), a feature of colorectal tumors with DNA mismatch repair defect. Seventy-two patients with metastatic colorectal cancer were included in our retrospective study. A complete response to irinotecan was observed in 1 patient and a partial response in 10 pat...

Tumorigenesis has long been thought to be a multistep process (Foulds, 1958); however, only recently has it become possible to identify the molecular events that underlie the initiation and progression of human tumors (Weinberg, 1989; Bishop, 1987). Colorectal tumors provide an excellent system in which to search for and study the genetic alterations involved in the development of a common huma...

aim : we aimed to explore the frequency of braf v600e mutation in iranian patients with colorectal cancer (crc) as well as its association with clinic pathological characteristic of patients.   background : crc is the third leading cause of cancer related death. there is a growing body of data showing the association of braf v600e mutation with malignant transformation and clinical outcome of d...

T cell infiltration into colorectal tumors has been shown to correlate with improved patient outcomes. However, more detailed information on the makeup and relationships between the infiltrating T cell subsets is lacking. We therefore correlated the extent of immune infiltration into colorectal tumors with the frequencies of various T cell subsets. We prospectively recruited 22 patients at the ...

Recently, an inducible microsomal human prostaglandin E synthase (mPGES) was identified. This enzyme converts the cyclooxygenase (COX) product prostaglandin (PG) H(2) to PGE(2), an eicosanoid that has been linked to carcinogenesis. Increased amounts of PGE(2) have been observed in many tumor types including colorectal adenomas and cancers. To further elucidate the mechanism responsible for incr...

Colorectal cancer is usually considered a disease of the elderly. However, a small fraction of patients develops colorectal cancer earlier. The aim of our study was to define the frequency of known hereditary colorectal syndromes and to characterise genetic and epigenetic features of early nonhereditary tumors. Thirty-three patients ≤40 years with diagnosis of colorectal cancer and 41 patients ...

Colorectal (CR) tumors are usually curable if detected before metastasis. Because genetic alterations are associated with the development of these tumors, mutant genes may be found in the stool of individuals with CR neoplasms. The stools of nine patients whose tumors contained mutations of K-ras were analyzed. In eight of the nine cases, the ras mutations were detectable in DNA purified from t...

Somatic mutations in DNA mismatch repair genes have been observed in sporadic tumors as well as ceHlines and xenografts derived from such tumors implicating genetic defects of mismatch repair genes in the devel opment of such tumors. However, the proportion of sporadic tumors in which mismatch repair genes have been inactivated has not been deter mined accurately. We have analyzed 66 sporadic c...

PURPOSE The relationship between global hypomethylation, chromosomal instability (CIN), and microsatellite instability (MSI) remains unclear in colorectal cancer. The aim of this study was to investigate the relationship between global methylation status, loss of heterozygosity (LOH), and MSI in sporadic colorectal cancer. EXPERIMENTAL DESIGN We determined global methylation levels in 80 spor...

MAC30 is highly expressed in several types of tumors including colorectal cancers, however, its clinicopathological and biological significance in colorectal cancers is currently not known. The aim of our study was to investigate MAC30 expression in distant normal mucosa, adjacent normal mucosa, primary tumors and metastases of colorectal cancer, and to determine the relationship between MAC30 ...