strychnine and Neoplasms

Ferroptotic cell death is characterized by iron-dependent lipid peroxidation that is initiated by ferrous iron and H

Topics: Activating Transcription Factor 3; Amino Acid Transport System y+; Animals; Antineoplastic Agents; Catalase; Cell Line, Tumor; Endoplasmic Reticulum Stress; Ferroptosis; Humans; Hydrogen Peroxide; Iron; Mice, Inbred BALB C; Mice, Nude; NADPH Oxidase 4; Neoplasms; Strychnine; Superoxide Dismutase-1; Up-Regulation; Xenograft Model Antitumor Assays

Autophagy is an important tightly controlled cellular process that regulates cellular homeostasis and is involved in deciding cell fate such as cell survival and death. The role of autophagy in many intracellular signaling pathways explains its interaction with other different types of cell death, including apoptosis and immunogenic cell death (ICD). The reports showed the complex and intriguing relationship existing between autophagy and immune system signaling pathways. However, the role of autophagy in ICD remains to be clearly elucidated. In this study, we demonstrated that Brucine, a clinically-used small molecule in traditional Chinese medicine, elicited autophagy inhibition. Brucine also triggered cell stress and induced features of ICD, including calreticulin (CRT) exposure and high-mobility group box 1 (HMGB1) release in MDA-MB-231 and CT26 cancer cells. Brucine impaired autolysosomal degradation and exerted a feedback regulation of ERK1/2-mTOR-p70S6K signaling cascade. Brucine-elicited ICD was confirmed by the rejection of CT26 tumor cells, implanted in the mice after vaccination with Brucine-treated CT26 cells. The impaired autophagy contributed to Brucine-induced ICD, as knock-down of Atg5 significantly reduced Brucine-elicited CRT exposure and HMGB1 release. Our results revealed Brucine as a novel autophagy regulator, ICD inducer and hitherto undocumented role of autophagy in ICD. Thus, these results imply the importance of Brucine in cancer immunotherapy. Therefore, Brucine may be used as an ICD inducer and improve its application in cancer treatment with minimized toxicity.

Topics: Animals; Autophagy; Autophagy-Related Protein 5; Calreticulin; Cell Death; Cell Line, Tumor; Drugs, Chinese Herbal; Gene Knockdown Techniques; HMGB1 Protein; Humans; Immunotherapy; Lysosomes; MAP Kinase Signaling System; Mice; Neoplasms; Phytotherapy; Strychnine

The overwhelming majority of drugs exert their pharmacological effects after reaching their target sites of action, however, these target sites are mainly located in the cytosol or intracellular organelles. Consequently, delivering drugs to the specific organelle is the key to achieve maximum therapeutic effects and minimum side-effects. In the work reported here, we designed, synthesized, and evaluated a novel mitochondrial-targeted multifunctional nanoparticles (MNPs) based on chitosan derivatives according to the physiological environment of the tumor and the requirement of mitochondrial targeting drug delivery. The intelligent chitosan nanoparticles possess various functions such as stealth, hepatocyte targeting, multistage pH-response, lysosomal escape and mitochondrial targeting, which lead to targeted drug release after the progressively shedding of functional groups, thus realize the efficient intracellular delivery and mitochondrial localization, inhibit the growth of tumor, elevate the antitumor efficacy, and reduce the toxicity of anticancer drugs. It provides a safe and efficient nanocarrier platform for mitochondria targeting anticancer drug delivery.

Topics: Animals; Antineoplastic Agents; Apoptosis; Chitosan; Chromatography, High Pressure Liquid; Cytoplasm; Cytosol; Drug Carriers; Drug Delivery Systems; Drug Liberation; Hep G2 Cells; Hepatocytes; Humans; Hydrogen-Ion Concentration; Lysosomes; Male; Mice; Mice, Inbred ICR; Microscopy, Confocal; Mitochondria; Nanoparticles; Nanotechnology; Neoplasm Transplantation; Neoplasms; Rats; Rats, Wistar; Schiff Bases; Strychnine

Two porphyrin-brucine quaternary ammonium salts were immobilized on gold nanoparticles and their suitability for both in vitro and in vivo photodynamic therapy (PDT) was assayed using the basaloid squamous cell carcinoma PE/CA-PJ34 cell line. In vitro PDT experiments revealed that the gold nanoparticle-bound conjugates were less effective than unbound conjugates in killing cells. However, the same conjugates were more effective in reducing tumor size in vivo, with complete tumor regression observed.

Topics: Alkylation; Animals; Biological Transport; Cell Death; Cell Line, Tumor; Gold; Humans; Intracellular Space; Metal Nanoparticles; Mice; Neoplasms; Photochemotherapy; Porphyrins; Solvents; Strychnine

Isostrychnopentamine (ISP) is an indolomonoter-penic alkaloid that is present in the leaves of Strychnos usambarensis, an East African small tree. We have reported previously pro-apoptotic effects induced in vitro by ISP in the human HCT-116 colon cancer cell line, a model that displays relative sensitivity to apoptosis. In the present study, we observed that the in vitro growth inhibitory activities of ISP are similar in cancer cells that display sensitivity versus resistance to apoptosis. We made use of the U373 glioblastoma and the A549 non-small cell lung cancer (NSCLC) cell lines as models relatively resistant to apoptosis, and the human PC-3 prostate cancer cell line as a model relatively sensitive to apoptosis. While ISP induced transient decreases in [ATP]i and apoptosis in human U373 GBM cells, it did not provoke such features in A549 NSCLC cells. It thus seems that ISP-induced anti-cancer activity can lead to pro-apoptotic effects as a consequence, while apoptosis seems not to be the main cause by which ISP induces cancer cell death. ISP is a compound that merits further investigations in order to: i) identify the mechanism(s) of action by which it kills cancer cells, and ii) hemisynthesize novel ISP derivatives aiming to overcome, at least partly, the resistance of metastatic cancers to apoptosis.

Topics: Adenosine Triphosphate; Antineoplastic Agents, Phytogenic; Apoptosis; Brain Neoplasms; Breast Neoplasms; Carbolines; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Female; Glioblastoma; Humans; Inhibitory Concentration 50; Lung Neoplasms; Male; Neoplasms; Plant Leaves; Prostatic Neoplasms; Strychnos; Time Factors