Sporadic Colorectal Cancer Development Shows Rejuvenescence Regarding Epithelial Proliferation and Apoptosis

Leiszter Katalin

Udvardyné Galamb Orsolya

Sipos Ferenc

Krenács Tibor

Veres Gábor

Wichmann Barnabás

Kalmár Alexandra

Patai Árpád

Tóth Kinga

Valcz Gábor

Molnár Béla

Tulassay Zsolt

SE/ÁOK/K/I. Sz. Gyermekgyógyászati Klinika

SE/AOK/K/II. Sz. Belgyógyászati Klinika

SE/AOK/I/I. Sz. Patológiai és Kísérleti Rákkutató Intézet

Semmelweis Egyetem

2014-03-28T12:21:49Z

2014-03-28T12:21:49Z

2013

2014-03-28T12:15:42Z

BACKGROUND AND AIMS: Sporadic colorectal cancer (CRC) development is a sequential process showing age-dependency, uncontrolled epithelial proliferation and decreased apoptosis. During juvenile growth cellular proliferation and apoptosis are well balanced, which may be perturbed upon aging. Our aim was to correlate proliferative and apoptotic activities in aging human colonic epithelium and colorectal cancer. We also tested the underlying molecular biology concerning the proliferation- and apoptosis-regulating gene expression alterations. MATERIALS AND METHODS: Colorectal biopsies from healthy children (n1 = 14), healthy adults (n2 = 10), adult adenomas (n3 = 10) and CRCs (n4 = 10) in adults were tested for Ki-67 immunohistochemistry and TUNEL apoptosis assay. Mitosis- and apoptosis-related gene expression was also studied in healthy children (n1 = 6), adult (n2 = 41) samples and in CRC (n3 = 34) in HGU133plus2.0 microarray platform. Measured alterations were confirmed with RT-PCR both on dependent and independent sample sets (n1 = 6, n2 = 6, n3 = 6). RESULTS: Mitotic index (MI) was significantly higher (p<0.05) in intact juvenile (MI = 0.33±0.06) and CRC samples (MI = 0.42±0.10) compared to healthy adult samples (MI = 0.15±0.06). In contrast, apoptotic index (AI) was decreased in children (0.13±0.06) and significantly lower in cancer (0.06±0.03) compared to healthy adult samples (0.17±0.05). Eight proliferation- (e.g. MKI67, CCNE1) and 11 apoptosis-associated genes (e.g. TNFSF10, IFI6) had altered mRNA expression both in the course of normal aging and carcinogenesis, mainly inducing proliferation and reducing apoptosis compared to healthy adults. Eight proliferation-associated genes including CCND1, CDK1, CDK6 and 26 apoptosis-regulating genes (e.g. SOCS3) were differently expressed between juvenile and cancer groups mostly supporting the pronounced cell growth in CRC. CONCLUSION: Colorectal samples from children and CRC patients can be characterized by similarly increased proliferative and decreased apoptotic activities compared to healthy colonic samples from adults. Therefore, cell kinetic alterations during colorectal cancer development show uncontrolled rejuvenescence as opposed to the controlled cell growth in juvenile colonic epithelium.

Journal Article

pagination=e74140, 10 pages; journalVolume=8; journalIssueNumber=10; journalTitle=PLOS ONE;

http://repo.lib.semmelweis.hu//handle/123456789/66

doi:10.1371/journal.pone.0074140

2429576

000327519000023

urn:issn:1932-6203