In Vitro Human Cancer Models for Biomedical Applications

Autophagy-related mechanisms for treatment of multiple myeloma

Multiple myeloma (MM) is a type of hematological cancer that occurs when B cells become malignant. Various drugs such as proteasome inhibitors, immunomodulators, and compounds that cause DNA damage can be used in the treatment of MM. Autophagy, a type 2 cell death mechanism, plays a crucial role in determining the fate of B cells, either promoting their survival or inducing cell death. Therefore, autophagy can either facilitate the progression or hinder the treatment of MM disease. In this review, autophagy mechanisms that may be effective in MM cells were covered and evaluated within the contexts of unfolded protein response (UPR), bone marrow microenvironment (BMME), drug resistance, hypoxia, DNA repair and transcriptional regulation, and apoptosis. The genes that are effective in each mechanism and research efforts on this subject were discussed in detail. Signaling pathways targeted by new drugs to benefit from autophagy in MM disease were covered. The efficacy of drugs that regulate autophagy in MM was examined, and clinical trials on this subject were included. Consequently, among the autophagy mechanisms that are effective in MM, the most suitable ones to be used in the treatment were expressed. The importance of 3D models and microfluidic systems for the discovery of new drugs for autophagy and personalized treatment was emphasized. Ultimately, this review aims to provide a comprehensive overview of MM disease, encompassing autophagy mechanisms, drugs, clinical studies, and further studies.

Experimental Murine Models for Colorectal Cancer Research

Colorectal cancer (CRC) is the third most prevalent malignancy worldwide and in both sexes. Numerous animal models for CRC have been established to study its biology, namely carcinogen-induced models (CIMs) and genetically engineered mouse models (GEMMs). CIMs are valuable for assessing colitis-related carcinogenesis and studying chemoprevention. On the other hand, CRC GEMMs have proven to be useful for evaluating the tumor microenvironment and systemic immune responses, which have contributed to the discovery of novel therapeutic approaches. Although metastatic disease can be induced by orthotopic injection of CRC cell lines, the resulting models are not representative of the full genetic diversity of the disease due to the limited number of cell lines suitable for this purpose. On the other hand, patient-derived xenografts (PDX) are the most reliable for preclinical drug development due to their ability to retain pathological and molecular characteristics. In this review, the authors discuss the various murine CRC models with a focus on their clinical relevance, benefits, and drawbacks. From all models discussed, murine CRC models will continue to be an important tool in advancing our understanding and treatment of this disease, but additional research is required to find a model that can correctly reflect the pathophysiology of CRC.

Cytotoxic, Antibacterial, and Antioxidant Activities of the Leaf Extract of Sinningia bullata

Sinningia bullata is a tuberous member of the flowering plant family Gesneriaceae. Prior to this work, the antibacterial, antioxidant, and cytotoxic properties of S. bullata were undetermined. Here, we prepared different extracts from the leaf, stem, and tuber of S. bullata and investigated their pharmacological activities. The leaf extract of S. bullata, obtained by 100% acetone (Sb-L-A), had the highest total flavonoid content, antioxidation capacity, and cytotoxic and antibacterial activities. Sb-L-A displayed a broad range of antibacterial activities against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The inhibition zones of Sb-L-A ranged from 8 to 30 mm and were in the following order: S. aureus > E. coli > P. aeruginosa. Incubation of B16F10 melanoma cells with Sb-L-A at a concentration of 80 μg/mL caused deaths at the rate of 96%, reduced migration by 100%, suppressed proliferation and colony formation by 99%, and induced apoptosis, which was observed in 96% of the B16F10 cells. In addition, the cytotoxic activities of Sb-L-A were synergistically enhanced when coacting with the antitumor drug epothilone B. Sb-L-A was also used to determine the cytotoxic effects against 4T1 mammary carcinoma cells. Sb-L-A of 60 μg/mL boosted the distribution of the G2 phase from 1.4% to 24.4% in the B16F10 cells. Accordingly, Sb-L-A might suppress melanoma cell proliferation by inducing G2 cell-cycle arrest. The most abundant compounds in Sb-L-A were identified using gas chromatography-mass spectrometry. Overall, the collective data in this study may indicate the pharmacological potentials of Sb-L-A for possible medical applications.

Cytotoxic Activities and the Allantoinase Inhibitory Effect of the Leaf Extract of the Carnivorous Pitcher Plant Nepenthes miranda

Nepenthes are carnivorous pitcher plants that have several ethnobotanical uses, such as curing stomachache and fever. Here, we prepared different extracts from the stem, leaf, and pitcher of Nepenthes miranda to further investigate their pharmacological potential. The leaf extract of N. miranda obtained by 100% acetone (N. miranda-leaf-acetone) was used in this study to analyze the cytotoxic activities, antioxidation capacity, antibacterial activity, and allantoinase (ALLase) inhibitory effect of this plant. The cytotoxic effects of N. miranda-leaf-acetone on the survival, apoptosis, and migration of the cancer cell lines PC-9 pulmonary adenocarcinoma, B16F10 melanoma, and 4T1 mammary carcinoma cells were demonstrated. Based on collective data, the cytotoxic activities of N. miranda-leaf-acetone followed the order: B16F10 > 4T1 > PC-9 cells. In addition, the cytotoxic activities of N. miranda-leaf-acetone were synergistically enhanced when co-acting with the clinical anticancer drug 5-fluorouracil. N. miranda-leaf-acetone could also inhibit the activity of ALLase, a key enzyme in the catabolism pathway for purine degradation. Through gas chromatography−mass spectrometry, the 16 most abundant ingredients in N. miranda-leaf-acetone were identified. The top six compounds in N. miranda-leaf-acetone, namely, plumbagin, lupenone, palmitic acid, stigmast-5-en-3-ol, neophytadiene, and citraconic anhydride, were docked to ALLase, and their docking scores were compared. The docking results suggested plumbagin and stigmast-5-en-3-ol as potential inhibitors of ALLase. Overall, these results may indicate the pharmacological potential of N. miranda for further medical applications.

Anticancer and Antioxidant Activities of the Root Extract of the Carnivorous Pitcher Plant Sarracenia purpurea

The carnivorous pitcher plant Sarracenia purpurea exhibits many ethnobotanical uses, including the treatments of type 2 diabetes and tuberculosis-like symptoms. In this study, we prepared different extracts from the leaves (pitchers), stems, and roots of S. purpurea and investigated their antioxidant and anticancer properties. To evaluate the extraction efficiency, we individually used different solvents, namely methanol, ethanol, acetone, and distilled water, for S. purpurea extract preparations. The root extract of S. purpurea, obtained by 100% acetone (S. purpurea-root-acetone), had the highest anticancer activities, antioxidation capacity (the DPPH activity with IC₅₀ of 89.3 ± 2.2 μg/mL), antibacterial activities, total phenolic content (33.4 ± 0.7 mg GAE/g), and total flavonoid content (107.9 ± 2.2 mg QUE/g). The most abundant compounds in S. purpurea-root-acetone were identified using gas chromatography-mass spectrometry; 7,8-Dihydro-α-ionone was the major compound present in S. purpurea-root-acetone. In addition, the co-cytotoxicity of S. purpurea-root-acetone (combined with the clinical anticancer drug 5-fluorouracil (5-FU) on the survival, apoptosis, proliferation, and migration of the 4T1 mammary carcinoma) was examined. The combination of 5-FU with S. purpurea-root-acetone could be highly efficient for anti-4T1 cells. We also found that S. purpurea-root-acetone could inhibit the enzymatic activity of human dihydroorotase (huDHOase), an attractive target for potential anticancer chemotherapy. The sic most abundant compounds in S. purpurea-root-acetone were tested using an in silico analysis via MOE-Dock software for their binding affinities. The top-ranked docking conformations were observed for 7,8-dihydro-α-ionone and stigmast-5-en-3-ol, suggesting the inhibition potential against huDHOase. Overall, the collective data in this study may indicate the pharmacological potentials of S. purpurea-root-acetone for possible medical applications.