Association between chemotherapeutic effect and apotosis-related gene in gastrointestinal cancer
Grant-in-Aid for Scientific Research (C)
|Research Institution||Osaka City University|
NAKATA Bunzo Osaka City University, Medical School, Research Associate, 医学部, 助手 (60271178)
|Project Fiscal Year
1996 – 1998
Completed(Fiscal Year 1998)
|Budget Amount *help
¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1998 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1997 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1996 : ¥800,000 (Direct Cost : ¥800,000)
|Keywords||gastrointestinal cancer / anticancer drug / apoptosis / p53 / SSCP / DNA sequencing / apoptotic index / interleukin-1beta converting enzyme / 消化器癌 / 抗癌剤 / SSP法 / DNAsequencing / interleukin-1β converting enzyme / SSCP法 / p63 / bax / bcl-2 / Fas抗原 / ICE / TUNEL法|
1. Association between chemosensitivity and apoptosis related protein expression
We studied immunohistochemical staining for the endoscopic biopsy specimens of the patients with gastric cancer treated with 5-FU+low dose cisplatin (FP) therapy. Among 18 patients with p53 positive (mutant type) carcinomas, 3 patients were responders of FP therapy. On the contrary, 10 of 12 patients with p53 negative tumors (wild type) showed the response to chemotherapy (P=0.04). The results suggested the patients with wild type p53 gastric carcinomas may be responders to FP therapy. Among the Bax-positive cases, the patients with Bc1-2-positive tumors were significantly more chemoresistant (P=0.036) and had worse prognosis (P=0.008) than Bc1-2-negative cases.
2. Association between chemosensitivity and interleukin 1-beta converting enzyme (ICE) activity in human gastric cancer cell line
It has been reported ICE may represent a final common pathway of apoptosis. We observed the peaks of ICE activities of ga
stric cancer cell lines, OCUM-2M, OCUM-2M/DDP, Kato-III, and MKN-28 at 3hrs after exposure to cisplatin. The regression value was 0.66 between the IC_<50> to cisplatin and ICE activity ratio (ICE activity at 3hrs after exposure cisplatin/that of no treatment cells). It suggested ICE may be a predictor of chemosensitivity to cisplatin as a early response protein. Moreover, the significant lower levels of ICE activity and apoptotic index in the cisplatin resistant cell, OCUM-2M7DDP after exposure to cisplatin than those of its parent cell, OCUM-2M.The result indicated the relation between ICE activity and apoptosis.
3. p53 mutation site associated with chemosensitivity
p53 gene analyses were performed with SSCP and DNA direct sequencing for 8 gastrointestinal carcinomas treated with FP therapy. Foru of 6 responders (partial response) had wild type p53 gene whereas 2 non-responders (no change) had mutant p53 gene. A partial response tumor had point mutation at codon 259 of exon 7, while a no change tumor had 13bp deletion at codon 241-245 of exon 7. The result showed DNA direct se1quencing was required to identify p53 mutation site related with chemosensitivity. We analyzed p53 genes in other 22 gastrointestinal carcinomas which are treating with oral 5-FU derivatives. We are observing the prognosis of these patients as indicator of chemotherapeutic effect to accomplish the analysis of p53 mutation site associated with chemosensitivity.
SSCP法によるp53の解析では、FP療法を行った胃癌、食道癌、膵癌8例でPR6例中4例がwild typeであり、NC2例はいずれもmutant typeであった。遺伝子からみてもp53の変異と化学療法の奏効度に相関があると考えられた。DNA sequencingによるp53遺伝子の解析ではparital response症例でexon7、codon259のpoint mutationを認めたが、同じexon7でもcodon241-245の13bpのdelitionを示す例では奏効度no changeであり、exon単位の解析(SSCP)だけでは不十分なことが示唆された。FP症例以外に胃癌11例、大腸癌6例、膵癌1例、肝癌3例、胆管癌1例の切除標本を用いてp53遺伝子解析を行い、外来で経口によるフッ化ピリミジン系の抗癌剤投与をおこなっているが、その効果とp53変異部位の解析には長期の予後観察が必要で、現在観察を継続中である。 Less
Research Output (8results)