[A case of a giant rectal gastrointestinal stromal tumor radically resectable after treatment with neoadjuvant imatinib mesylate].

A 64-year-old male patient was diagnosed with rectal gastrointestinal stromal tumor(GIST)by prostate biopsy, because of high PSA. We considered that a radical operation was impossible because the tumor occupied the pelvis, and we suspected prostate invasion. After neoadjuvant chemotherapy(imatinib mesylate 400 mg/day), the tumor size was reduced(90×85 mm→60×50mm), and we could thus perform radical resection. The patient is currently receiving adjuvant chemotherapy (imatinib mesylate 400 mg/day), without recurrence.

Expression of circadian clock genes in human colorectal adenoma and carcinoma.

Circadian rhythms are fundamental biological systems in most organisms. Epidemiological and animal studies have demonstrated that disruption of circadian rhythms is linked to tumor progression and mammalian tumorigenesis. However, the clinical significance of in situ clock gene expression in precancerous and cancerous colorectal lesions remains unknown. The present study aimed to investigate mRNA transcript levels of circadian clock genes within human colorectal cancer and adenoma tissue sections. Using in situ hybridization, the expression of key clock genes, including period circadian protein homolog (Per) 1 and 2, cryptochrome 1 (Cry1), circadian locomoter output cycles protein kaput (Clock), brain and muscle ARNT-like protein 1 (Bmal1) and casein kinase 1ε (CK1ε) were retrospectively examined in 51 cases of colorectal carcinoma and 10 cases of adenoma. The expression of clock genes was almost undetectable in the majority of adenomas, whereas positive expression of clock genes was observed in 27-47% of carcinomas. Notably, positive Per1, Per2 and Clock staining in colorectal carcinomas were each significantly associated with a larger tumor size (P=0.012, P=0.011 and P=0.009, respectively). Tumors with positive Per2 and Clock expression tended to exhibit deeper depth of invasion and were generally more advanced than tumors that did not express these genes (P=0.052 and P=0.064, respectively). However, no statistically significant association was observed between clock gene expression and clinicopathological variables, including histopathological differentiation, lymph node metastasis, depth of invasion or disease stage, although Per2-positive tumors tended to be associated with poorer overall survival (P=0.060). The results of the current study suggest that dysregulated expression of clock genes may be important in human colorectal tumorigenesis.

Expression of copper-transporting P-type adenosine triphosphatase (ATP7B) in human hepatocellular carcinoma.

One of the major obstacles in the treatment of hepatocellular carcinoma (HCC) is the intrinsic/acquired resistance to cisplatin-based chemotherapy. Copper-transporting P-type adenosine triphosphate (ATP7B) has been reported to be associated with cisplatin resistance in vitro. However, the expression of ATP7B has not previously been addressed in human liver and HCC. Our purpose was to investigate ATP7B expression in human liver and hepatocellular carcinoma and its clinical significance. We retrospectively examined the expression of ATP7B in primary hepatocellular carcinoma. Immunohistochemical analysis of ATP7B was performed using a monoclonal antibody against ATP7B in 19 surgically removed hepatocellular carcinomas. A variable degree of cytoplasmic staining of tumor cells was observed in 21.1% (4/19) of the analyzed carcinomas. ATP7B expression was not observed in normal hepatic cells. Strong expression of ATP7B was observed in all the analyzed bile ducts. These findings suggest that overexpression of ATP7B in hepatocellular carcinoma might be associated with unfavorable clinical outcome in patients treated with cisplatin-based chemotherapy. Further, ATP7B is expressed in bile duct epithelial cells, where it may mediate copper secretion into bile fluid.

Thymidine phosphorylase gene mutation is not a primary cause of mitochondrial neurogastrointestinal encephalomyopathy (MNGIE).

OBJECTIVE: The authors identified a patient with mitochondrial neurogastrointestinal encephalomyopathy (MNGIE), who completely fulfilled the clinical criteria with low thymidine phosphorylase (TP) activity. However, the same homozygotic S471L TP gene mutation was also found in her unaffected mother, but with normal TP activity. To elucidate the pathogenesis of MNGIE, we performed the analysis below. METHODS: We analyzed the TP gene mutation in the proband and 145 unrelated individuals by direct sequence and restriction fragment length polymorphism (RFLP). TP activity was determined by the spectrophotometric method for each TP S471L genotype. RESULTS: Among 145 normal persons, the S471L homozygote mutants were identified in 2.76% and their enzyme activity was normal. CONCLUSION: TP gene mutation is not a primary cause of MNGIE, but with a mitochondrial deletion mutation, a single nucleotide polymorphism (SNP) of the TP gene may be crucial in the pathogenesis of MNGIE.