Overexpression of E2F1 associated with LOH at RB locus and hyperphosphorylation of RB in non-small cell lung carcinoma

金沢大学大学院医学系研究科保健学専攻Purpose E2F1 plays a critical role in cell proliferation, and its function is controlled by the retinoblastoma (RB) protein. We examined the expression of E2F1 and the aberration of RB gene and protein to elucidate what factors contribute to the overexpression of E2F1 in non-small cell lung carcinomas. Methods The expression level of E2F1 in tissues of non-small cell lung carcinomas was measured by means of quantitative reverse transcription-polymerase chain reaction and immunohistochemistry. For RB, we examined loss of heterozygosity (LOH) by PCR-restriction fragment length polymorphism and a variable number of tandem repeats, and protein expression by immunohistochemistry. Results Fifteen cases of carcinoma (46%) showed high transcription levels of E2F1 gene. Immunohistochemically, almost all (14 of 15) cases overexpressing E2F1 mRNA were positive for E2F1 protein. LOH at the RB locus was found in 13 of 30 informative cases. In 13 cases with LOH, ten showed overexpression of E2F1 mRNA and protein. Immunohistochemical positivity for phosphorylated RB protein was also closely correlated with overexpression of E2F1. Conclusions Our results suggest that overexpression of E2F1, induced both by LOH at the RB locus and anomalous phosphorylation of the RB protein, is involved in the development of non-small cell lung carcinoma

In situハイブリダイゼーションによる子宮頸部上皮性病変への16, 18ヒト乳頭腫ウイルスの組み込みの検出

高感度 in situ ハイブリゼーション（ISH）法と高感度 PCR 法を用いて子宮頸部扁平上皮病変と腺病変での16型と18型のヒト乳頭種ウイルス感染頻度検索し、核への組み込みの頻度を ISH 法で決定した。16, 18型は PCR と ISH でともに、扁平上皮系病変のグレードが高まるにつれて感染頻度が上がった。浸潤扁平上皮癌のすべての例で ISH で組み込み型を示し、CIN1 の全てでエピソーム型を示した。腺系病変では PCR でも ISH でも16型より18型が多く検出され、そのほぼすべてが組み込み型だった。CIN2ではエピソーム型が多くCIN3では組み込み型が多かった。これらから16, 18型の核への組み込みは扁平上皮病変でも腺病変でも癌の初期に現れる変化、あるいは癌への進展を強く示唆する所見と考えられた。Highly sensitive in situ hybridization (ISH) and highly sensitive PCR methods were used to determine the infection of HPV type 16 (HPV 16) and type 18 (HPV 18) and the integration of them into the cells of squamous and glandular lesions of the uterine cervix. The frequency of HPV infection detected by ISH and PCR increased with progression of squamous lesions. All cases of ICC showed the integrated pattern of positive signals with ISH and all positive cases in CIN1 showed the episomal pattern. In CIN2 episomal patterns were more frequent than integrated pattern and in CIN3 integrated pattern were more frequent. Glandular lesions showed a greater frequency of HPV 18 than HPV 16 on nested PCR and ISH, and almost all of ISH-positive cases showed the integrated pattern. These data suggested that integration of HPV 16 and 18 is required for carcinogenesis in both squamous cell carcinoma and adenocarcinoma of the uterine cervix

Adhesiveness of β5 integrin variant lacking FNK767–769 is similar to that of the prototype containing FNKFNK764–769

金沢大学大学院医学系研究科保健学専攻Little is known about the functions of two different β5 integrins: repeated-FNK (FNKFNK764–769) and single-FNK (FNK764–766) amino acid sequences in the cytoplasmic domain. We examined whether they occurred as germ line mutations or somatic mutations associated with neoplastic transformation, and whether there were functional alterations. Out of six cultured cell lines, only KATO-III cells had the single-FNK β5 sequence. The single-FNK β5 was found in 9 out of 79 patients with colon carcinoma, but no somatic mutations were detected in cancerous tissues. CHO cells were transformed with expression vectors containing single-FNK or repeated-FNK β5 cDNA, which were derived from KATO-III cells. CHO cells transfected with single-FNK and repeated-FNK showed similar adhesiveness to, and proliferative activity on, vitronectin substrates