The Effect Of C-Met Inhibitor PHA-665752in Combination With Bevacizumab Or Cetuximab On Colon Cancer HCT-116

Background: Colorectal cancer is one of the malignant tumors and threatto human health seriously. In the United States, the incidence and mortality ofcolorectal cancer became the third issue, and showed an increasing trend inour country. Because the early symptoms is not obvious and early screeningmeasures is lack, most of the patients diagnosised has been the advancedstage. At present, the standard treatment of colorectal cancer is comprehensivetreatment based on surgery. Most of the patients of colorectal cancer needadjuvant chemotherapy. However, drug resistance and sever side effectslimited them widely use. Recently, targeted drugs achieved encouragingefficacy in the treatment of colorectal cancer patients.It is necessary to search for new therapeutic targets and sensitized meansfor conventional therapy. Recently studies has found that HGF/c-Metsignaling pathway plays an important role in the metastasis of colorectalcancer. In the vitro experiments, HGF can promote the growth and movementof the tumor cells, and c-Met have the ability to induce tumor cellmesenchymal-to-epithelial(EMT). Some clinical studies have shown that c-Met was over-expression in colorectal adenomas, colorectal cancer and themetastasis of colorectal cancer, but was lower-expression in normal tissues ofintestinal. It is reported also show that the expression of c-Met can promotethe progression of colorectal cancer. Compared with the health adults, thelevel of HGF in serum was significantly increased in the patients of colorectalcancer. Moreover the later stages, the higher HGF levels, patients with livermetastases of colorectal cancer have the more higher levels of HGF. c-Metinhibitors can reverse VEGF or EGFR inhibitor resistance, and combinationtherapy can suppress tumors more significantly. However, based on moleculartargeted therapy of c-Met combined traditional chemotherapy or other targeted therapies in the treatment of colorectal cancer has reported rarely.Objective: To evaluate the proliferation efficacy of PHA-665752incombination with bevacizumab or cetuximab in human colon cancer cell lineHCT-116.Method:1The Pyrosequencing technology was used to detect the KRAS genestatus of colon cancer cell HCT-116.2MTT assay was used to detect the proliferative efficacy of differentconcentrations of PHA-665752, Bevacizumab or Cetuximab in HCT-116, andused to detect the proliferative efficacy of PHA-665752in combination withBevacizumab or Cetuximab in HCT-116.3Flow cytometry was used to detect the efficacy of cell cycle andapoptosis of PHA-665752in combination with Cetuximab in HCT-116.Results:1The KRAS gene status of colon cancer cells HCT-116is KRASp.G13D mutation.2MTT assay:(1)With the treatment of PHA-665752，the higher the concentration, themore significant inhibition of proliferation in HCT-116(P＜0.01).Bevacizumab was no inhibition of proliferation, ever if increase the drugconcentration to320μg/ml(P＞0.05). Cetuximab was no inhibition ofproliferation, ever if increase the drug concentration to80μg/ml(P＞0.05). Weselect the optimal drug concentration and duration of action according theseresults.(2)Treatment with PHA-665752in combination with Bevacizumab hasthe stronger inhibition of proliferation than control group and Bevacizumabmonotherapy treatment, but has no significant difference with PHA-665752monotherapy treatment in HCT-116.(3)Treatment with PHA-665752in combination with Cetuximab has thestronger inhibition of proliferation than control group and Bevacizumab orCetuximab monotherapy treatment in HCT-116. 3Flow cytometry:(1)Cell cycle: The percentage of G0/G1of control group is(47.33±0.45)%, the percentage of G0/G1of Cetuximab group is (43.83±0.35)%and less than control group(P＜0.01). The percentage of G0/G1ofPHA-665752group is (71.90±0.26)%and more than control group(P＜0.01).The percentage of G0/G1of PHA-665752in combination with Cetuximabgroup is (60.00±0.70)%and more than control group(P＜0.01), but less thanPHA-665752group(P＜0.01).(2)Cell apoptosis: The ratio of apoptosis of the control group is(6.04±0.06)%. The ratio of apoptosis of Cetuximab group is (5.99±0.13)%and has no significant difference with control group(P＞0.05). The ratio ofapoptosis of PHA-665752group is (10.35±0.02)%and more than controlgroup(P＜0.01). The ratio of apoptosis of PHA-665752in combination withCetuximab group is (13.55±0.08)%and more than control group, Cetuximabgroup and PHA-665752group(P＜0.01).Conclusion:1The colon cancer cells HCT-116is KRAS p.G13D mutation.2HCT-116was sensitive to c-Met inhibitor PHA-665752, but notsensitive to Bevacizumab or Cetuximab.3C-Met inhibitors PHA-665752can increase the sensitivity of HCT-116to Cetuximab, but can not increase the sensitivity of HCT-116toBevacizumab.