肝細胞癌中活化之受器酪胺酸激脢之尋找及分析

Identification and Analysis of Activated Receptor Tyrosine Kinase in Hepatocellular Carcinoma

鍾翎(Ling Chung)

指導教授 ： 鄭永銘

國立臺灣大學/醫學院/病理學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.01474

摘要

肝細胞癌(Hepatocellular carcinoma, HCC)在台灣位居第二的癌症死因，並於全球為第六大癌症。肝細胞癌通常難以及早發現，因為往往於中期才可被發現。由於不同肝癌患者症狀及基因表現差異極大，且致病因素相當廣泛，肝癌被認為是一個極複雜的疾病。肝細胞癌的分子機制，特別是早期，目前仍未十分清楚。分析不同的腫瘤中有時會發現牽涉到不同的傳導途徑。受器酪胺酸激脢(Receptor Tyrosine Kinase, RTK)在胚胎發育及許多生理機制上皆參與傳遞，在人類癌症致病過程中扮演非常關鍵性的角色，此外，因為受器酪胺酸激脢成為可被藥物抑制，受器酪胺酸激脢也是大部份標靶治療的標的。
我們利用人類的受器酪胺酸激脢陣列尋找在肝細胞癌中主要被活化的受器酪胺酸激脢，我們發現EGFR, IGF1R是最常被活化的受器酪胺酸激脢。我們選擇Ror1, AXL, and FGFR3作為研究的目標。這些基因被敲減(knockdown)時會抑制下游訊息傳遞，被磷酸化的AKT幾乎消失，而當AXL and FGFR3被敲減時，被磷酸化的ERK也有些微減少。雖然細胞增生的能力並無明顯的改變，但生成腫瘤的能力卻下降。我們以bosutinib抑制AXL時，發現細胞移動能力下降。總結來說，抑制此三個受器酪胺酸激脢中其中任一個，可能影響肝細胞癌細胞的生長或移動。
ROR1, AXL,及FGFR3可能可以提供肝細胞癌標靶治療的新標的，因為肝細胞癌複雜的致病機制，我們需要對其訊息傳遞途徑更多瞭解，以發展更有系統的治療方式。

關鍵字

肝細胞癌 ； 受器酪胺酸激脢

並列摘要

Hepatocellular carcinoma (HCC) is the second most common cause of cancer mortality in Taiwan and the sixth most common malignancy worldwide. The risks are the highest in South-East Asia and sub-Saharan Africa. HCC typically has poor prognosis because it is often diagnosed at an advanced stage. Because of the heterogeneous phenotypic and genetic traits of patients and a wide range of risk factors, HCC is considered as a complex disease. The molecular mechanisms of HCC, particularly in the early stage, are still poorly understood. Analysis of different tumors revealed several core pathways are frequently altered in certain types of cancer. Receptor tyrosine kinases (RTK) are critically involved in the progression of human cancer. Besides, RTKs are the targets of most molecularly targeted therapy. Therefore, RTKs offer unique opportunities for pharmacological intervention.
Here we used the human phospho-RTK Array to define the compendium of activated RTKs in HCC. We found several RTKs constitutively expressed in HCC cell lines. EGFR and IGF1R are the most commonly activated RTKa. We choose ROR1, AXL, and FGFR3 as the potential targets to study. Knockdown of these genes was accompanied by inhibition of downstream signaling events. In western blotting, pAKT were almost abolished when these three genes were knocked down individually, and knockdown of AXL and FGFR3 also slightly reduced phosphorylation of ERK. Colony formation ability was measured by soft agar assay. The colony formation ability decreased in all the knockdown cell lines. MTT assay was used to detect the proliferation ability and shows that knockdown cells do not have significantly reduced proliferation ability. Targeting AXL by bosutinib inhibits HCC cells migration. In conclusion, inactivation of any single one of these three RTKs may affect HCC cell growth or migration.
Our study of ROR1, AXL, and FGFR3 might offer new opportunities for therapeutic intervention. Since HCC has complex network of signaling pathway, it is important for us to further identify the downstream signaling pathways to develop the more effective systemic treatment option.

並列關鍵字

Hepatocellular carcinoma ； Receptor tyrosine kinase

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