Synthesis and Biological Evaluation of Prodrugs For Nitroreductase Based 4-β-Amino-4'-Demethylepipodophyllotoxin As Potential Anticancer Agents

A series of prodrugs for nitroreductase based 4-β-amino-4'- Demethylepipodophyllotoxin as potential anticancer agents were synthesized, and their antiproliferative activities in vitro showed compounds 2b (IC50=0.77, 0.83 and 1.19 μM) and 2d (IC50=0.98, 0.91 and 1.58 μM) were greatly selectively toxic to tumor cells A-549, HeLa and HepG2, respectively, and lower damage to normal WI-38 cells in comparison with positive agent Etoposide and Demethylepipodophyllotoxin, and induced cell cycle arrest in the G2/M phase with a concomitant decrease in the population of G1 phase in HeLa cells, which were accompanied by apoptosis. Furthermore, Molecular docking model showed that compounds 2b and 2d appeared to form stable bonds with NTR 1DS7. Taken together, these conjugates have the potential to be developed as anti-tumor drugs.

Pseudogene RPL32P3 regulates the blood–tumor barrier permeability via the YBX2/HNF4G axis

The existence of the blood–tumor barrier (BTB) severely hinders the transport of anti-tumor drugs to brain tumor tissues. Selectively opening BTB is of great significance to improve the chemotherapy effect of glioma. Pseudogenes have been recognized as important regulators in various biologic processes. In this study, we identified that ribosomal protein L32 pseudogene 3 (RPL32P3) was highly expressed in glioma-exposed endothelial cells (GECs). Knockdown of RPL32P3 decreased the expression of tight junction-related proteins (TJPs) and increased BTB permeability. Subsequent analysis of the underlying mechanism indicated that RPL32P3 recruited lysine methyltransferase 2 A (KMT2A) to the Y-box binding protein 2 (YBX2) promoter region and mediated H3K4me3 to promote YBX2 transcription. Highly expressed YBX2 bound and stabilized hepatocyte nuclear factor 4 gamma (HNF4G) mRNA. Highly expressed HNF4G directly bound to the promoters of TJPs ZO-1, occludin and claudin-5 to promote their transcriptional activities and regulated BTB permeability. The simultaneous knockdown of RPL32P3, YBX2, and HNF4G combined with doxorubicin (DOX) increased the apoptosis of glioma cells. In conclusion, the current study indicated that RPL32P3 knockdown increased BTB permeability through the YBX2/HNF4G pathway. These findings may provide new targets for the comprehensive treatment of glioma.

Expressing MLH1 in HCT116 cells increases cellular resistance to radiation by activating the PRKAC

Mut L homolog-1 (MLH1) is a key DNA mismatch repair protein which participates in the sensitivity to DNA damaging agents. However, its role in the radiosensitivity of tumor cells is less well characterized. In this study, we investigated the role of MLH1 in cellular responses to ionizing radiation (IR) and explored the signaling molecules involved. The isogenic pair of MLH1 proficient (MLH1+) and deficient (MLH1–) human colorectal cancer HCT116 cells was exposed to IR for 24 h at the dose of 3 cGy. The clonogenic survival was examined by the colony formation assay. Cell cycle distribution was analyzed with flow cytometry. Changes in the protein level of MLH1, DNA damage marker γH2AX, and protein kinase A catalytic subunit (PRKAC), a common target for anti-tumor drugs, were examined with Western blotting. The results showed that the HCT116 (MLH1+) cells demonstrated increased radio-resistance with increased S population, decreased G2 population, a low level of γH2AX, a reduced ratio of phosphorylated PRKACαβ to total PRKAC, and an elevated level of total PRKAC and phosphorylated PRKACβII following IR compared with the HCT116 (MLH1–) cells. Importantly, silencing PRKAC in HCT116 (MLH1+) cells increased the cellular radiosensitivity. In conclusion, MLH1 may increase cellular resistance to IR by activating PRKAC. Our finding is the first to demonstrate the important role of PRKAC in MLH1-mediated radiosensitivity, suggesting that PRKAC has potential as a biomarker and a therapeutic target for increasing radio-sensitization.

Targeting the Tumor Microenvironment: A Literature Review of the Novel Anti-Tumor Mechanism of Statins

Statins is widely used in clinical practice as lipid-lowering drugs and has been proven to be effective in the treatment of cardiovascular, endocrine, metabolic syndrome and other diseases. The latest preclinical evidence shows that statins have anti-proliferation, pro-apoptotic, anti-invasion and radiotherapy sensitization effects on tumor cells, suggesting that statins may become a new type of anti-tumor drugs. For a long time, mevalonate pathway has been proved to play a supporting role in the development of tumor cells. As an effective inhibitor of mevalonate pathway, statins have been proved to have a direct auxiliary anti-tumor effect in a large number of studies. In addition, anti-tumor effects of statins through ferroptosis, pyroptosis, autophagy and tumor microenvironment (TME) have also been gradually discovered. However, the specific mechanism of the antitumor effect of statins in the tumor microenvironment has not been clearly elucidated. Herein, we reviewed the antitumor effects of statins in tumor microenvironment, focusing on hypoxia microenvironment, immune microenvironment, metabolic microenvironment, acid microenvironment and mechanical microenvironment.

Current Strategies for Cancer Cell-Derived Extracellular Vesicles for Cancer Therapy

Cancer cell-derived extracellular vesicles (CEVs), a novel type of therapeutic agent in cancer treatment, can be prepared from the autocrine secretion of various cancer cells, the direct extraction of cancer cells and the combination of cancer cell-derived membranes with advanced materials. With various bioactive molecules, exosomes are produced by cells for intercellular communication. Although cancer cell-derived exosomes are known to inhibit tumor apoptosis and promote the progression of cancer, researchers have developed various innovative strategies to prepare anti-tumor vesicles from cancer cells. With current strategies for anti-tumor vesicles, four different kinds of CEVs are classified including irradiated CEVs, advanced materials combined CEVs, chemotherapeutic drugs loaded CEVs and genetically engineered CEVs. In this way, CEVs can not only be the carriers for anti-tumor drugs to the target tumor area but also act as immune-active agents. Problems raised in the strategies mainly concerned with the preparation, efficacy and application. In this review, we classified and summarized the current strategies for utilizing the anti-tumor potential of CEVs. Additionally, the challenges and the prospects of this novel agent have been discussed.

Development of Some Novel Coumarin-Chalcone Compounds as Anti-proliferative Agents

Introduction: Cancer is the world's second leading cause of death and morbidity, behind only heart failure, which claimed the lives of 18.2 million people in 2020. While massive initiatives to establish newer leads and innovative chemotherapeutic methods for combating different types of cancer, continues to be a major concern around the world. As a result, identifying cell-cycle inhibitors and apoptotic triggers to fight cancer cells is an appealing method for finding and developing new anti-tumor drugs. Materials and Methods: The present study involves the rational development and characterization (both physicochemical and spectroscopy) of coumarin-chalcone compounds (A1–A10) and their anti-proliferative potentials against cancer lines of breast cancer origin (MDA-MB468, MDA-MB231, and MCF-7) and non-cancer breast epithelial cell (184B5). Results: The compound A2 exhibited the highest anti-proliferative activity against the cell line MDA-MB-231 as indicated by the GI50 value of 10.06 μM, the compound A6 exhibited the highest anti-proliferative activity against the cell line MDA-MB-468 as indicated by the GI50 value of 17.54 μM, the compound A1 exhibited the highest anti-proliferative activity against the cell line MCF-7 as indicated by the GI50 value of 25.86 μM, and the compound A6 exhibited the highest anti-proliferative activity against the cell line 184B5 as indicated by the GI50 value of 23.26 μM. Conclusion: Furthermore, the research urges medicinal chemists to choose chalcone prototypes with well-defined pathways and SARs while developing more powerful inhibitors. Furthermore, it opens up new pathways for the discovery of anti-cancer derivatives using low molecular weight ligands.

The Hh pathway promotes cell apoptosis through Ci-Rdx-Diap1 axis

Apoptosis is a strictly coordinated process to eliminate superfluous or damaged cells, and its deregulation leads to birth defects and various human diseases. The regulatory mechanism underlying apoptosis still remains incompletely understood. To identify novel components in apoptosis, we carry out a modifier screen and find that the Hh pathway aggravates Hid-induced apoptosis. In addition, we reveal that the Hh pathway triggers apoptosis through its transcriptional target gene rdx, which encodes an E3 ubiquitin ligase. Rdx physically binds Diap1 to promote its K63-linked polyubiquitination, culminating in attenuating Diap1−Dronc interaction without affecting Diap1 stability. Taken together, our findings unexpectedly uncover the oncogenic Hh pathway is able to promote apoptosis through Ci-Rdx-Diap1 module, raising a concern to choose Hh pathway inhibitors as anti-tumor drugs.

Advanced Nano-Carriers for Anti-Tumor Drug Loading

Chemotherapy is one of the important means of tumor therapy. However, most of the anti-tumor drugs that currently used in clinic are hydrophobic non-specific drugs, which seriously affect the efficacy of drugs. With the development of nanotechnology, drug efficacy can be improved by selecting appropriate biodegradable nanocarriers for achieving the controlled release, targeting and higher bioavailability of drugs. This paper reviewed the research progress of anti-tumor drug nanoparticle carriers, which mainly summarized the materials used for anti-tumor drug nanoparticle carriers and their effects in anti-tumor drugs, as well as the targeted drug delivery methods of anti-tumor drugs based on nanocarriers.

Pneumatosis intestinalis and spontaneous perforation associated with drug toxicity in oncologic patients : a case series

Pneumatosis Intestinalis (PI) is a rare radiological finding defined as the presence of extra-luminal gas within the intestinal wall. Several anti-tumor drugs can induce a damage of the gastrointestinal walls as an adverse effect, causing loss of mucosal integrity and endoluminal gas diffusion, responsible for PI development. We retrospectively analyzed 8 cases of PI detected through radiological imaging in oncologic patients undergoing various therapeutic regimens: five patients were receiving chemotherapy, two molecular targeted therapy (MTT) and one immunotherapy. Three patients were asymptomatic and pneumatosis was incidentally detected at routinary follow-up CT and then treated conservatively. Five patients presented acute abdomen symptoms and in these cases bowel perforation was the cause of death. Our experience confirms PI and perforation as rare complications of drug toxicity, especially in oncologic patients treated with combinations of different anticancer drugs and documented the second reported case of PI associated with atezolizumab and alectinib single administration.