Study On The Mechanism By Which The Novel Fluorescent Compound CPC Inhibits The Growth Of Cancer Cells

Background and objectiveCancer is a global health concern. According to the World Cancer Report 2015 from World Health Organization (WHO), the global cancer incidence and mortality rate accounted for 13% of deaths worldwide and has shown an increasing tendency. Currently, cancer has been the main threat for human’s health. Lung cancer is still the first cancer deaths for men both in developing and developed countries. In addition, human cervical cancer is the main culprit which hazards women’s health. Unfortunately, there is no effective means to cure tumor. Besides surgery, chemotherapy is still the main means of cancer treatment. Although it can prolong cancer patients’life, cancer patients have got to suffer severe side effects accompanied by chemotherapy, such as bone marrow suppression, gastrointestinal toxicity and hair loss. Hence, it is an urgent to develop novel, selective anti-neoplastic compounds and to find new regulator and new signal pathway in cancer.At present, inducing cell apoptosis, arresting cell cycle and suppressing cell migration are the main cancer treatment strategy. Chemotherapy is one of the main methods for the treatment of cancer, whose aim is to inhibit the growth of cancer cells or to induce cell death by chemical drugs. Apoptosis, also known as type I programmed cell death, is involved in the development and differentiation of organism and play a pivotal role in the maintenance of cellular homeostasis. In cancer cells, the cell apoptosis pathway is inhibited. Therefore, apoptosis induction is an effective way to suppress the growth of cancer cells. Unlimited proliferation is the hallmark of cancer cells. Inducing cell cycle arrest is also a strategy to inhibit cancer cell excessive proliferation. Malignant tumor cells have high transfer tendency, which is one of the reasons why cancer is hard to cure. Thus, suppressing cell migration can control cancer development. Autophagy, also known as type II programmed cell death, participates in the turning over of cellular proteins and organelles. The degree of autophagy determines the fate of the cell:moderate autophagy promotes cell survival; excessive autophagy induced cell death. Studying the cross-talk between apoptosis and autophagy and define the nature of autophagy will facilitate the discovery of effective targets and establish reasonable cancer treatment strategy. Chemical genetics, as an emerging interdisciplinary science, is aiming at illuminating biological issues by using small chemicals. Based on chemical genetics, screening effective and selective small chemicals to inhibit the growth of cancer cells and studying their new mechanisms have been the hotspot of chemical genetics.So far, mounting researchers have put their focus on organelle-based therapy. Mitochondria are not only power plant, but also important therapy targets for cancer treatment. To design mitochondria-targetable anticancer compound and to unravel the anti-tumor mechanism will be conducive to the discovery of leading compounds.Our study focuses on the roles of small chemicals in the regulation of cancer cell growth. We hope that we can screen a novel fluorescent compound which can effectively restrain the growth of tumor cells and study on the mechanism of novel fluorescent compound in the suppression of cancer cell growth. We are in the hope of finding a new regulator or signal pathway which modulate the growth of cancer cells and hunting for novel anti-cancer target and new anti-cancer therapy.Research methods1. The morphological changes were observed by a phase contrast microscope2. The cell viability was measured by SRB assay3. LDH assay was conducted to detect cell necrosis4. Hochest 33258 was performed to determine the apoptosis of cancer cells5. The protein level of LC3 and p62 were measured by Western blot6. The dots of EGFP-MAP1LC3 were detected by a point scanning laser confocal microscope7. The phosphorylation of RPS6KB1 and EI4EBP1 were analyzed by western blot8. Western blot was used to explore the cleave of PARP and CASP39. The distribution of CPC was analyzed by using a point scanning laser confocal microscope10. Flow cytometry was used to evaluate the effect of CPC on cell cycleResults1. CPC induced cell apoptosis in Hela cells2. CPC induced mTOR-dependent protective autophagy3. CPC inhibited the nuclear translocation of Nrf24. CPC targeted mitochondria5. CPC induced cell cycle arrest in A549 cells6. CPC inhibited cell migration in A549 cellsConclusionsIn conclusion, we screened a mitochondria-targetable novel fluorescent compound CPC by using cancer cell lines and studied the mechanism of it in the suppression of cancer cell growth. We found it had excellent anti-cancer activities. It could induce apoptosis, inhibit cell migration and arrest cell cycle in cancer cells. In Hela cells, it induced cell apoptosis and protective autophagy. It can inhibit the nuclear translocation of Nrf2 and elevate the ROS level. More importantly, this compound can selectively accumulate in mitochondria. In A549 cells, CPC could significantly arrest the cell cycle and inhibit cell migration.