Monomeric Compound FLBG-B Inhibits Proliferation,Migration And Invasion In Human Nasopharyngeal Carcinoma Cells

Nasopharyngeal carcinoma?NPC?is a malignancy that is common in Southern China and shows the highest invasive and metastatic features among head and neck cancers.Radiotherapy and chemotherapy remains the primary mode of NPC treatment,and the main reasons for failure treatment is distant metastatic and recurrence.We have isolated a xanthone namely FLBG-B from mangosteen pericarps and found it own obvious anti-viability in NPC cells.Although relationships between FLBG-B and some cancer was already studied,the effects of FLBG-B on NPC and the molecular mechanism of its effect have not yet reported.Our studies showed that FLBG-B inhibited cell proliferation of NPC cell lines:HK1 and HONE1 in a dose-dependent manner.Futhermore,FLBG-B might modulate cell-cycle related proteins to induce cell-cycle arrest and reduce migration ability via regulation EMT related proteins.In addition,appling the beta-galsctose glucoside enzyme kit and TEM,we found FLBG-B induced senescence and necrosis in NPC cells.These results indicate that FLBG-B has obvious anti-cancer ability in NPC and our work provides basis for the development FLBG-B as a novel anti-cancer agent in NPC.Objective:Explore the effect of FLBG-B,extracted from Garcinia oblongifolia Champ,on the proliferation,migration and invasion of nasopharyngeal carcinoma?NPC?HK1 and HONE1 cells and elucidate its possible mechanism.Methods:Examine the effect of FLBG-B on proliferation of nasopharyngeal carcinoma HK1 and HONE1 cells lines using MTS assay;Colony formation assay was performed to determine the inhibiting effects of FLBG-B on NPC cells;Evaluate the effect of FLBG-B on the migration and invasion ability of HK1 and HONE1 cell lines using Transwell migration assay;The expressions of protein related to EMT and cell-cycle and possible passway were detected by Western blot;Detect the effect of FLBG-B on E-cadherin in nasopharyngeal carcinoma cells at transcriptional level by using q-PCR;Detect the effect of FLBG-B on aging in nasopharyngeal carcinoma cell line by?-galactosidase kit;Transmission electron microscope was used to evaluate the effects of FLBG-B on the changes of ultrastructures and suborganelles in NPC cells.Results:MTS assay showed that FLBG-B signifcantly inhibited cell viability of HK1 and HONE1 cell lines in a dose-dependent manner.The IC₅₀value of FLBG-B after 24 h of incubation was 12.57±0.01?M?10.91±0.89?M respectively;Colony formation assay showed that FLBG-B decreased colony forming ability of NPC cells;Transwell migration and invasion assay showed that compared with the blank control group,7.5?M FLBG-B suppressed migration in HK1 and HONE1 cell lines obviously,implying that FLBG-B inhibited the migration and invasion in NPC cells;Western blot resluts indicated that FLBG-B arrested cell cycle in G₀/G₁ phase of cell cycle by decreasing the protein expression of CDK2,Cyclin D1 and Cyclin A2 but increasing the expression of p21 and p27 in a dose-dependent manner.Furthermore,FLBG-B reversed EMT in NPC cells by reducing the expression of p-Vimentin,snail and slug but increasing the expression of E-cadherin,producing relative biological functions;The results of q-PCR show that 10?M FLBG-B significantly up-regulate the mRNA levels of E-cadherin;Aging experiments showed that 7.5?M FLBG-B could induce senescence in HONE1 cells compared with blank control,but there was no obvious aging induction effect on HK1;The results of transmission electron microscope showed that FLBG-B caused mitochondria swelling and formation of autophagosome in HK1 cells in a dose-dependent manner.Conclusion:FLBG-B inhibit the ability of proliferation and colony formation in NPC cells in a dose-dependent manner;FLBG-B induced cell cycle arrest in G₀/G₁ phase in NPC cell lines,which was related to regulating the protein expression of CDK2,Cyclin D,Cyclin A2,p21and p27;FLBG-B inhibited the ability of migration and invasion in NPC cells by regulating of EMT related proteins such as E-cadherin,p-Vimentin,Snail and Slug;FLBG-B promotes the expression of E-cadherin at transcription level;FLBG-B promotes senescence in HONE1 cells but has no aging induction effect on HK1 cells;FLBG-B induced necrosis in HK1 cells in a dose-and time-dependent manner.