Abstract
Lung-cancer is the leading cause of cancer-related death worldwide. Cytogenetic analysis have been performed last two decades, but comparative analysis of karyotypes of small cell lung cancer (SCLC) from between Japan and America has not been precisely studied. Six Japanese and one American SCLC cell lines examined were hyperdiploid to neartetraploid with modal number of 52-91. These cells had a complex karyotype with more than 10 rearrangements. The karyotypic patterns were relatively consistent alterations involved long arm of chromosomes 1, 3, 7 and 11, and short arm of chromosomes 1 and 3. Higher rearrangements specially associated with translocations and deletions were observed in short and long arms of chromosomes 3 (3p21&3q25), and recurrently long arms of chromosome 7 (7q36 and 7q23). Although the chromosome of SCLC is too complex and G-banding analysis could not resolve all of many of the karyotypic abnormalities seen, several potentially site -specific abnormalities such as deletions of chromosome 3p, 7q and 3q, and amplifications of 3p, 7q, 1q, 11p, 2p and 12p in 6 SCLC cell lines established from chemotherapy resistant patients tumor cells. Losses of short arm chromosome 11 and 12 (11p, 12p) and long arm of chromosome 13 (13q), and amplifications of chromosomes 2, 11, 12, 13 and 19 (2p, 11p, 12p, 13q, 19p) were recurrently identified in the several cell lines, being different from published chromosomal abnormalities in American SCLC, which suggests geographical difference of SCLC karyotype. Also, these abnormal patters were largely different from non-small cell lung carcinoma (NSCLC). Unknown oncogenes localizing on these chromosome breakpoints for translocation or deletion region might be associated with the pathogenesis of SCLC. Present analysis can provide information on significant genes involved pathogenesis of SCLC.
Highlights
Lung cancer is the leading cause of cancer death inJapan and worldwide, accounting for over 4931 deaths in 1975-1977 in Japan alone (Yoshimura & Yamashita 1982)
Lung cancer can be histologically sub-classified into 4 major categories: squamous cell carcinoma, lung adenocarcinoma, and undifferentiated large cell carcinoma, comprising non-small cell lung cancer (NSCLC), and undifferentiated small cell carcinoma (SCLC)
Squamous carcinoma was predominant in male, and male and female sex ratio was 8:1, but lung adenocarcinoma was higher in female. 5- year survival rates were 14.4%, 14.4%, 11.9%, 5.4% and 1.3% for epidermoid carcinoma, adenocarcinoma, large cell carcinoma, small cell carcinoma intermediated cell type and oat cell type, respectively (Yoshimura & Yamashita, 1982)
Summary
Japan and worldwide, accounting for over 4931 deaths in 1975-1977 in Japan alone (Yoshimura & Yamashita 1982). Epidermoid carcinoma accounted for 46.6% of male cases and 18.8% in female cases, while adenocarcinoma was 61.2% of female cases and 30.3% in male cases in Japan. Squamous carcinoma was predominant in male, and male and female sex ratio was 8:1, but lung adenocarcinoma was higher in female. The squamous cell carcinomas are most common, the majority of the lung tumors so far cytogenetically investigated have been the small- cell type. The del(3)(p14p23) is well established as a specific marker for SCLC and NSCLC of lung cancers. It is found predominantly in SCLC, but it has been present in only some cases or most NSCLC cases examined. Present analysis revealed a possibility that karyotype of SCLC is geographically different
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.