Screening And Mechanism Researching Of Small Molecule Drug For Anti-lung Squamous Carcinoma

Lung cancer is the only malignant tumor of which morbidity and mortality have been increasing in recent years,and the mortality has been the most stable in male cancer.It has become the leading cause of cancer death worldwide.Lung Cancer were divided into Small Cell Lung Cancer(Small Cell Lung Cancer,SCLC)and non-small Cell Lung Cancer(Non-Small Cell Lung Cancer,NSCLC)in pathology.NSCLC accounts for approximately 85% of Lung Cancer patients,and the majority were diagnosed at mid-last period,have lost the operative opportunity.Currently,excepting for surgical therapy,there are still radiotherapy,chemotherapy and molecular targeted therapy.Chemotherapy in locally advanced lung cancer still plays an important role in preoperative adjuvant therapy,such as neoadjuvant chemotherapy,chemoradiation and synchronous chemotherapy and molecular targeted therapy.There is no significant improvement in the survival rate of patients with lung cancer,based on traditional platinum-type single and multidrug chemotherapy regimens,and all kinds of chemotherapy drugs which have certain toxicity and side effects.In recent years,the rise of molecular targeted therapy has improved the survival time of patients with gene sensitivity,at least for two years.Therefore,the research and development of anti-cancer drugs with high efficiency and low toxicity have provided a broad research platform for improving the long-term survival rate of NSCLC patients.Research shows that induction of tumor cell apoptosis is a key factor in anti-tumor therapy of chemotherapy drugs,and has became a hotspot in anti-tumor research and a screening target for anticancer drugs.Therefore,the discovery and research of some selectively targeted drugs for apoptosis may provide a new method for the treatment of lung cancer.There are lots of records for the treatment of suspected lung cancer with Traditional Chinese herbal medicine,but we don't know the specific composition due to its structural uncertainty.In view of the traditional Chinese medicine extraction,purification and found of the existence of reasonable structure,exact activity and higher stability,it has derived a lot of antitumor drug chemistry.Therefore,the research of small molecular compounds of traditional Chinese medicine is very important in the research and development of anticancer drugs,and some drugs have already been used in clinical,such as paclitaxel.As above,the effective ingredients of traditional Chinese medicine have the effect of inducing apoptosis on tumor cells,and these active ingredients work on the target gene for malignant proliferation,selectively inducing tumor cell apoptosis,with no effect on normal cells or small effects,which provides a new research strategy for the treatment of malignant tumor,and new hope on the treatment of patients with NSCLC.Isoalantolactone is a traditional Chinese medicine.It is a sesquiterpene ester compound which is isolated from the Inula helenolume.Although the related research is limited,existing studies have shown that Isoalantolactone could inhibit tumor cell proliferation,has certain anti-tumor activity on tumors,such as colon cancer,melanoma,ovarian cancer,prostate cancer,lung cancer and leukemia.However,there have been no reports of antitumor studies on lung squamous cell carcinoma.In this study,the lung squamous carcinoma cell line SK-MES-1 was selected for our study.Through MTT cell proliferation experiment we found that Isoalantolactone significantly inhibited the proliferation of NSCLC cells,with the concentration dependence.Through flow cytometry assay,we found that Isoalantolactone can significantly induce apoptosis of NSCLC cells,and also with apparent concentration dependence.Through flow cytometry We detected the cell cycle distribution,the result shows that Isoalantolactone induced SK-MES-1 cell cycle arrest at G1 / G0 phase.We detected the Mitochondrial Membrane Potential(MMP)and intracellular Reactive Oxygen Species(ROS)levels through flow cytometry,the results show that MMP significantly decreased,and an increased level of ROS.By western blot assay we detected cell cycle and apoptosis protein expression changes,and the results show that Isoalantolactone could obviously increase the expression of p53 protein,inhibit G1 phase regulation protein,the retinoblastoma protein(Rb)expression.These results showed that Isoalantolactone could activate p53 signaling pathway,the transcription compounds bind with Rb protein,to inhibit pRb activity,blocking the cell cycle at G1 phase.At the same time we also observed pro-apoptotic proteins Bax increased and anti-apoptotic proteins Bcl-2 decreased,reducing the mitochondrial membrane potential,so as to activate mitochondrial apoptosis signaling pathways,promoting apoptosis factors release,to activate downstream cysteinyl aspartate specific proteinase(caspase),apoptotic protease cascade,eventually cracking its substrate,Poly AIAL-Ribose Polymerase(PARP).These results showed that Isoalantolactone could also induce NSCLC cell apoptosis through caspase passway.In this research we studied the antitumor effect and its molecular mechanism of Isoalantolactone on human lung squamous carcinoma cells.The results suggest that Isoalantolactone activated p53 signaling pathway and to activate mitochondrial apoptosis of SK-MES-1 cell.Thus,it can be seen that Isoalantolactone may develop into a potential anti-lung cancer chemotherapy drug,which can further provide theoretical basis for its entry into clinic.