A case of granulomatous inflammation of the sigmoid colon caused by a fish bone that resembled cancer.

This case involved a 76-year-old man. Total colonoscopy was performed as a second examination for colorectal cancer because of positive fecal occult blood results, revealing a neoplasm with ulceration in the sigmoid colon. We suspected type-3 colorectal cancer and performed a biopsy, but the biopsy diagnosis showed only an ulcer with active inflammation. Colonoscopic re-examination in a highly advanced medical institution revealed granulomatous inflammation of the sigmoid colon caused by a fish bone, and the fish bone was removed endoscopically. Granulomatous inflammation of the colon caused by a fish bone is very rare, but sometimes needs to be differentiated from cancer. Endoscopic therapy can also be an option, depending on abdominal findings and the penetration status of the fish bone into the large intestinal wall.

[Retrospective study of irinotecan plus fluorouracil and l-leucovorin chemotherapy for advanced and metastatic colorectal cancer].

Ten cases of advanced and metastatic colorectal cancer treated with irinotecan plus fluorouracil and l-leucovorin systemic chemotherapy (CPT-11/5-FU/l-LV) were investigated. The 10 patients consisted of 7 males and 3 females with a mean age of 64.3 years. We diagnosed adenocarcinoma of the colon in 2 patients and of the rectum in 8 patients. Five patients had liver and lung metastases, 1 had lymph node metastases, 1 had bone marrow metastases and 3 had recurrence in a pelvic lesion. All patients underwent 3-week chemotherapy regimen (CPT-11 50 mg/m2/week + 5-FU 400 mg/m2/week + l-LV 20 mg/m2/week). Five patients received this regimen as a first-line chemotherapy and the other patients as a second-line chemotherapy after 5-FU/l-LV chemotherapy. The effect was CR or PR in all patients receiving the regimen as a first-line chemotherapy. The progression free survival time was 6.8 months and mean survival time was 10.0 months in the first-line patients. Otherwise, all second-line patients had PD. The suppression of white blood cells (grade 1 or 2) was seen in 4 patients. All patients were able to receive the systemic chemotherapy in the outpatient setting. CPT-11/5-FU/l-LV chemotherapy appears to be an effective first-line chemotherapy for advanced and metastatic colorectal cancer.

Establishment of conditional vectors for hairpin siRNA knockdowns.

Small interference RNA (siRNA) is an emerging methodology in reverse genetics. Here we report the development of a new tetracycline-inducible vector-based siRNA system, which uses a tetracycline-responsive derivative of the U6 promoter and the tetracycline repressor for conditional in vivo transcription of short hairpin RNA. This method prevents potential lethality immediately after transfection of a vector when the targeted gene is indispensable, or the phenotype of the knockdown is lethal or results in a growth abnormality. We show that the controlled knockdown of DNA methyltransferase 1 (DNMT1) in human cancer resulted in growth arrest. Removal of the inducer, doxycycline, from treated cells led to re-expression of the targeted gene. Thus the method allows for a highly controlled approach to gene knockdown.