Integrative Analysis of SIX1 and Cancer Stem Cell Markers in Hepatocellular Carcinoma

Abstract

Objective: Transcription factor SIX1 aberrant expression has been shown in various mammalian tumors, and also recent studies indicated that SIX1 has a role in cancer stem cell properties. However, its roles in HCC cancer stem cell characteristics remain unclear. The aim of the study, to evaluate the EMT-inducer SIX1 and cancer stem cell markers expression profile in-vitro and in-vivo analyses. Material and Methods: SIX1 expression was suppressed by short hairpin RNA transduction in the SNU398 HCC cell line. Tumorsphere formation assay is a golden useful assay for cancer stem cell analysis. SIX1-dependent cancer stem cell markers PROM1, EPCAM, and OCT4 differential gene expression profiles were assessed in tumorsphere formation assay by RT-qPCR. Differential expression and correlation analyses were performed in transcriptome data in cirrhosis and HCC tissue samples. Results: Assessment of SIX1-knockdown expression of target genes in tumorsphere formation assay revealed PROM1, EPCAM expressions were significantly up-regulated but OCT4 gene expression was significantly down-regulated. Conformably, PROM1 and EPCAM expressions were inversely but OCT4 expression was positively correlated in transcriptome arrays in HCC tissues. Interestingly, to the evaluation of the same gene expressions were shown different patterns except, OCT4 in cirrhosis samples. The mRNA expression profiles did not change between cirrhosis and HCC samples in the SIX1, EPCAM, PROM1, and OCT4 gene expression profiles. Conclusion: Cancer stem cells are self‐renewable cell types and are responsible for cancer progression. Findings from this study highlight the SIX1 and cancer stemness-related genes expression correlations to improve our knowledge for HCC molecular signatures.

SIX1 ve Kanser Kök Hücre Belirteçlerinin Hepatoselluler Karsinomada Kapsamlı Analizi

Abstract

Amaç: SIX1 transkripsiyon faktörünün çeşitli memeli tümörlerinde anormal anlatımı ve SIX1’in kanser kök hücre karakterinde rol oynadığı son çalışmalarda belirlenmiştir. Bununla birlikte, HCC kanser kök hücrelerinde SIX1 transkripsiyon faktörünün rolü halen belirsizdir. Bu çalışmanın amacı, EMT-uyarıcı SIX1 ve kanser kök hücre belirteçlerinin anlatım profillerinin in-vitro ve in-vivo analizlerde değerlendirilmesidir. Gereç ve Yöntemler: SIX1 anlatımı, SNU398 HCC hücre hattında shRNA transdüksiyonu ile baskılandı. Tumor-küre formasyonu analizi, kanser kök hücre analizi için kullanılan önemli bir yöntemdir. SIX1-bağımlı kanser kök hücre belirteçleri PROM1, EPCAM ve OCT4 gen anlatım profilleri tümör-küre modelinde RT-qPCR ile değerlendirildi. Siroz ve HCC doku örneklerindeki transkriptom verilerinde genlerin anlatım ve korelasyon analizleri gerçekleştirildi. Bulgular: Kanser kök hücre belirteçlerinin SIX1-baskılanmış anlatımının değerlendirilmesi sonucunda PROM1 ve EPCAM anlatımlarının anlamlı artmasına karşın OCT4 anlatımının anlamlı olarak azaldığı belirlendi. HCC doku transkriptom analizinde SIX1 anlatımı ile PROM1 ve EPCAM anlatımının ters korelasyon, OCT4 anlatımında pozitif korelasyon tespit edildi. İlginç olarak aynı gen ifadelerinin siroz örneklerinde OCT4 dışındaki diğer genlerin anlatımlarında farklı paternler saptanmıştır. SIX1, EPCAM, PROM1 ve OCT4 gen mRNA profillerinde siroz ve HCC numuneleri arasında anlamlı farklılık saptanmadı. Sonuç: Kanser kök hücreleri kendi kendini yenileyebilen ve kanserin ilerlemesinde rol oynayan hücrelerdir. Çalışma sonucunda SIX1 ve kanser kök hücre ile ilişkili genlerin anlatım profillerinin aydınlatılması, HCC’nin moleküler yapısı hakkındaki bilgilerimizi geliştirmektedir.

Keywords

• SIX1,EMT,CSC,HCC

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