Disertasi

Pengaruh Sekretom Cancer-Associated Fibroblasts terhadap Transisi Epitel-Mesenkim dan Kepuncaan Sel Karsinoma Kolorektal melalui Jalur Pensinyalan Hepatocyte Growth Factor/c-Mesenchymal-Epithelial Transition receptor. = The Effect of Cancer-Associated Fibroblasts Secretomes to the Epithelial-Mesenchymal Transition and Stemness of Colorectal Carcinoma Cell through Hepatocyte Growth Factor/c-Mesenchymal-Epithelial Transition Receptor Pathway.

Pendahuluan: Cancer-associated fibroblasts (CAFs) merupakan populasi sel yang heterogen dan memiliki hubungan timbal balik dengan sel tumor. Bagaimana mekanisme molekuler yang mendasari pengaruh CAFs terhadap prognosis karsinoma kolorektal (KKR) masih belum diketahui. Penelitian ini bertujuan untuk mengetahui pengaruh sekretom CAFs terhadap transisi epitel-mesenkim (TEM), invasi dan kepuncaan sel KKR melalui jalur pensinyalan hepatocyte growth factor (HGF)/c-mesenchymal-transition receptor (c-Met) Metode: Dilakukan pemeriksaan histopatologi pada tiga puluh dua blok paraffin KKR untuk menilai tipe CAFs dan stroma, imunoekspresi α-SMA dan HGF, tumor budding, kedalaman invasi dan metastasis kelenjar limfe. Pemeriksaan in vitro berupa suplementasi sekretom fibroblast primer dari area tumor (CAFs) dan area non tumor dari tiga pasien KKR kepada sel lestari KKR (HT-29) untuk menilai pengaruhnya terhadap TEM, invasi dan kepuncaan sel KKR. Analisis statistik menggunakan uji beda proporsi, uji beda rerata berpasangan serta uji korelasi. Nilai p < 0,05 dianggap bermakna secara statistik. Hasil: Tipe CAFs dan metastasis kelenjar limfe berhubungan bermakna dengan derajat tumor budding. Sedangkan variabel lain pada pemeriksaan histopatologi tidak memperlihatkan hubungan yang bermakna. CAFs yang diisolasi dari pasien KKR memperlihatkan ekspresi mRNA α-SMA yang lebih tinggi, sedangkan ekspresi mRNA dan protein HGF memperlihatkan pola yang berbeda diantara ketiga pasang fibroblast. Suplementasi sekretom CAFs kepada sel HT-29 meningkatkan ekspresi mRNA c-Met sebagai reseptor HGF, meningkatkan ekspresi mRNA dan protein vimentin dan E-cadherin sebagai marka TEM, meningkatkan ekspresi mRNA MMP-2 sebagai marka invasi dan meningkatkan ekspresi mRNA CD44 dan CD133 sebagai marka kepuncaan. Terdapat korelasi positif bermakna antara c-Met dengan TEM dan kepuncaan serta korelasi positif kuat dan bermakna antara TEM dan kepuncaan sel KKR. Kesimpulan: Sekretom CAFs menginduksi TEM, invasi dan kepuncaan sel KKR melalui pensinyalan HGF/c-Met. Mekanisme molekuler ini mendasari hubungan yang bermakna antara tipe CAFs dengan tumor budding.
Kata kunci: karsinoma kolorektal, cancer-associated fibroblast, HGF/c-Met, transisi epitel-mesenkim, kepuncaan.


Introduction Cancer-associated fibroblasts (CAFs) are heterogeneous cell populations and have a cross-talks with tumor cells. How the molecular mechanism underlying the effect of CAFs on the prognosis of colorectal carcinoma (CRC) remains unknown. This study aimed to determine the effect of CAF secretomes on epithelial-mesenchymal transitions (EMT), invasion, and stemness of colorectal carcinoma cells through hepatocyte growth factor (HGF) / c-mesenchymalepithelial transition receptor (c-Met) signaling pathway. Methods: Histopathological examination was performed on thirty-two of formalin- fixed paraffin-embedded to evaluate CAFs and stroma type, α-SMA and HGF immunoexpression, tumor budding, invasion depth, and lymph node metastases. In vitro assay comprised of supplementation the secretomes of primary fibroblast tumor area (CAFs) and non-tumor area of three CRC patients to CRC cell line (HT29) to investigate their effect on EMT, invasion, and stemness of CRC cells. Statistical analysis using chi square, paired t and correlation test. P < 0.05 was considered significant. Results: CAFs type and lymph node metastases were significantly associated with tumor budding. While other variables on histopathological examination did not show a significant relationship. CAFs isolated from CRC patients showed higher αSMA mRNA expression, whereas mRNA and HGF protein expression showed different patterns between the three pairs of fibroblasts. Supplementation of CAF secretomes to HT-29 cells increases expression of c-Met mRNA as HGF receptors, mRNA, and protein of vimentin and E-cadherin as EMT markers, MMP-2 mRNA expression as invasion marker and increases expression of CD44 and CD133 mRNA as stemness markers. There is a significant positive correlation between cMet with EMT and stemness and also a significant positive correlation between EMT and the stemness of CRC cells. Conclusion: CAF secretomes induce EMT, invasion, and stemness of CRC cells through HGF / c-Met signaling. This molecular mechanism underlies the association of CAFs type and tumor budding.
Keywords: colorectal carcinoma, cancer-associated fibroblasts, HGF / c-Met, epithelial-mesenchymal transition, stemness.