Cytotoxic action of acetate on tumor cells of thymic origin: Role of MCT-1, pH homeostasis and altered cell survival regulation

The N-terminal signature motif on the transporter MCT1 is critical for CD147-mediated trafficking

The human Solute Carrier (SLC) family member, monocarboxylate transporter 1 (MCT1), transports lactic and pyruvic acid across biological membranes to regulate cellular pH and metabolism. Proper trafficking of MCT1 from the endoplasmic reticulum to the plasma membrane hinges on its interactions with the membrane-bound chaperone protein, CD147. Here, using AlphaFold2 modeling and copurification, we show how a conserved signature motif located in the flexible N-terminus of MCT1 is a crucial region of interaction between MCT1 and the C-terminus of CD147. Mutations to this motif-namely, the thymic cancer linked G19C and the highly conserved W20A-destabilize the MCT1-CD147 complex and lead to a loss of proper membrane localization and cellular substrate flux. Notably, the monomeric stability of MCT1 remains unaffected in mutants, thus supporting the role of CD147 in mediating the trafficking of the heterocomplex. Using the auxiliary chaperone, GP70, we demonstrated that W20A-MCT1 can be trafficked to the plasma membrane, while G19C-MCT1 remains internalized. Overall, our findings underscore the critical role of the MCT1 transmembrane one signature motif for engaging CD147 and identify altered chaperone binding mechanisms between the CD147 and GP70 glycoprotein chaperones.

Integrated Genomics and Transcriptomics Provide Insights into Salt Stress Response in Bacillus subtilis ACP81 from Moso Bamboo Shoot (Phyllostachys praecox) Processing Waste

Salt stress is detrimental to the survival of microorganisms, and only a few bacterial species produce hydrolytic enzymes. In this study, we investigated the expression of salt stress-related genes in the salt-tolerant bacterial strain Bacillus subtilis ACP81, isolated from bamboo shoot processing waste, at the transcription level. The results indicate that the strain could grow in 20% NaCl, and the sub-lethal concentration was 6% NaCl. Less neutral protease and higher cellulase and β-amylase activities were observed for B. subtilis ACP81 under sub-lethal concentrations than under the control concentration (0% NaCl). Transcriptome analysis showed that the strain adapted to high-salt conditions by upregulating the expression of genes involved in cellular processes (membrane synthesis) and defense systems (flagellar assembly, compatible solute transport, glucose metabolism, and the phosphotransferase system). Interestingly, genes encoding cellulase and β-amylase-related (malL, celB, and celC) were significantly upregulated and were involved in starch and sucrose metabolic pathways, and the accumulated glucose was effective in mitigating salt stress. RT-qPCR was performed to confirm the sequencing data. This study emphasizes that, under salt stress conditions, ACP81 exhibits enhanced cellulase and β-amylase activities, providing an important germplasm resource for saline soil reclamation and enzyme development.

Cytotoxic Action of Palladium-Based Compound on Prostate Stem Cells, Primary Prostate Epithelial Cells, Prostate Epithelial Cells, and Prostate Cell Lines

Objective

Prostate cancer is one of the most common types of cancer found to occur in males and is ranked as the second-highest cause of cancer-associated deaths among male patients. In this study, we have shown the influence of a new palladium-based anticancer agent in contrast to the six distinct prostate cancer lines and the primary cultures.

Methods

In this study, we have used six distinct prostate cell lines, that is, PNT2-C2, LNCaP, BPH-1, PC-3, PNT1A, and P4E6. The MTP and ATP assay were performed to evaluate the growth of the cell and the flow cytometry to investigate the status of the cell cycle. The antigrowth effect of the palladium complex was evaluated against different cell lines at three time zones 24 h, 48 h, and 72 h. [PdCl(terpy)] (capsule)-2H2O is synthesized by direct encapsulation of equimolar amounts of capsule ions into [Pd (terpy) Cl] Cl-2H2O.

Results

A comparative analysis was done on 25 mM etoposide and 12 mM cisplatin, cytotoxic agents. The lowest IC50 value at 72 hours was 0.128 mM for BPH-1 cell lines with 0.139 mM, whereas PNT2-C2 cells were found to be most resistant with IC50 values of 0.829 mM. The antigrowth effect of palladium complex on cell lines was measured using the MTS assay at 24, 48, and 72 hours. BPH-1, PNT2-C2, and PNT1A either possess normal tissues or have benign prostatic hyperplasia tissues whereas P4E6, PC-3, and LNCaP cell lines possess malignant origin. The Pd complex exhibited significant cytotoxic action in stem cells when compared against etoposide. An antigrowth effect was reported for Pd complex at lower concentration, but it was more cytotoxic than etoposide with significant cytotoxicity (P=0.001).

Conclusion

The palladium complex experienced a substantial antigrowth influence over most of the prostate tumor cell lines and the primary cultures, eventually, leading to the implementation of this Pd complex in the treating procedure of metastatic prostate cancer, which is tremendously resistant to the traditional treatment.

N-acetyl l-aspartate and Triacetin modulate tumor suppressor MicroRNA and class I and II HDAC gene expression induce apoptosis in Glioblastoma cancer cells in vitro

Glioblastoma multiforme (GBM), grade IV glioma and is aggressive, malignant primary brain cancer. Altered expression and activity of epigenetic proteins such as histone deacetylases (HDACs) are involved in GBM metastasis. Also, acetates are important to brain metabolites that regulate cell proliferation and apoptosis. Here, we have examined the effect of the acetates on the cell-cycle. U87MG cancer cells treated with N-acetyl l-aspartate (NAA) and sodium acetate have exhibited G1 phase cell-cycle arrest whereas U87MG cells treated with Triacetin (TA), and potassium acetate has induced G2/M cell cycle arrest. We have observed inhibition of histone deacetylase (HDAC) mRNA levels in acetate treated U87MG cells. Interestingly, acetates-treated U87MG cells have shown a significant reduction in the mRNA level of class II HDACs than class I HDACs. Acetate treated cells have exhibited an enhanced expression of various microRNAs such as miR-15b, miR-92, miR-101, miR-155, miR-199, miR-200, miR-223, miR-16, and miR-17 that are involved in the inhibition of cancer cell proliferation, invasion, migration, and angiogenesis. Further, these acetate molecules regulate genes involved in mammalian target of rapamycin complex 2 (mTORC2) such as mammalian stress-activated protein kinase-interacting protein (mSIN1), protein observed with Rictor 2 (Protor 2), and protein kinase C α (PKCα). The present study reveals the possible involvement of the mTORC2 complex during acetate-mediated HDAC inhibition, as well as microRNA modulation. Furthermore, molecular modeling studies were employed to understand the binding mode of these acetate molecules to mTOR, Rapamycin-insensitive companion of mammalian target of rapamycin (Rictor), and HDAC-8 proteins. Thus in this study, we have identified the pivotal role of acetates in the modulation of mTOR complex, epigenetic genes and provide structural as well as functional insights that will help in future drug discovery against GBM cancer therapy.

Nimbolide induces cell death in T lymphoma cells: Implication of altered apoptosis and glucose metabolism

Nimbolide is a tetranortriterpenoid derived from the leaves and flowers of Azadirachta indica (Neem). It exhibits anticancer activity against a variety of cancers by modulating various crucial features, including cell proliferation, apoptosis, and invasion and metastasis. More importantly, the cytotoxic effect of nimbolide has also been observed against T cell lymphoma, but the underlying mechanisms are still unexplored. So far, no study has been conducted to observe the effect of nimbolide on cancer cell metabolism. Therefore, the present investigation was designed to explore the molecular mechanisms of the antitumor potential of nimbolide against T cell lymphoma, a neoplastic disorder of thymic origin. In addition, we also unraveled the anti-glycolytic activity of nimbolide against T lymphoma cells with possible molecular mechanisms. Our results showed the cytotoxic action of nimbolide against three different cell lines of T cell lymphoma, namely Dalton's lymphoma, HuT-78, and J6. Nimbolide-induced apoptosis in T lymphoma cells by altering the level of reactive oxygen species, p53, Bcl2, Bax, and cytochrome c, with subsequent cleavage of caspase 3. Remarkably, nimbolide inhibited the expression of hypoxia-inducible factor-1α, glucose transporter 3, hexokinase II, and pyruvate dehydrogenase kinase 1, which led to the suppression of glycolysis with concomitant activation of oxidative phosphorylation. Hence, the results of the present investigation demonstrate that nimbolide exerts tumoricidal activity against T lymphoma cells via augmentation of apoptosis and reversal of altered cell metabolism. Thus, the present study provides a new insight for the therapeutic utilization of nimbolide against T cell lymphoma.

Methyl Jasmonate Cytotoxicity and Chemosensitization of T Cell Lymphoma In Vitro Is Facilitated by HK 2, HIF-1α, and Hsp70: Implication of Altered Regulation of Cell Survival, pH Homeostasis, Mitochondrial Functions

Methyl jasmonate (MJ) displays antineoplastic potential against numerous neoplastic cells. However, several mechanistic aspects of its antineoplastic action against malignancies of T cell origin remain elusive. The present investigation reports the novel targets of MJ and mechanistic pathways of MJ-mediated antineoplastic and chemosensitizing action against tumor cells derived from murine T-cell lymphoma, designated as Dalton's lymphoma (DL). The present study demonstrates that MJ directly docks to HIF-1α, hexokinase 2, and Hsp70 at prominent binding sites. MJ exhibits tumoricidal action against tumor cells via induction of apoptosis and necrosis through multiple pathways, including declined mitochondrial membrane potential, enhanced expression of ROS, altered pH homeostasis, an elevated level of cytosolic cytochrome c, and modulated expression of crucial cell survival and metabolism regulatory molecules. Additionally, this study also reports the chemosensitizing ability of MJ against T cell lymphoma accompanied by a declined expression of MDR1. This study sheds new light by demonstrating the implication of novel molecular mechanisms underlying the antitumor action of MJ against T-cell lymphoma and hence has immense translational significance.

Acetate Revisited: A Key Biomolecule at the Nexus of Metabolism, Epigenetics, and Oncogenesis - Part 2: Acetate and ACSS2 in Health and Disease

Acetate, the shortest chain fatty acid, has been implicated in providing health benefits whether it is derived from the diet or is generated from microbial fermentation of fiber in the gut. These health benefits range widely from improved cardiac function to enhanced red blood cell generation and memory formation. Understanding how acetate could influence so many disparate biological functions is now an area of intensive research. Protein acetylation is one of the most common post-translational modifications and increased systemic acetate strongly drives protein acetylation. By virtue of acetylation impacting the activity of virtually every class of protein, acetate driven alterations in signaling and gene transcription have been associated with several common human diseases, including cancer. In part 2 of this review, we will focus on some of the roles that acetate plays in health and human disease. The acetate-activating enzyme acyl-CoA short-chain synthetase family member 2 (ACSS2) will be a major part of that focus due to its role in targeted protein acetylation reactions that can regulate central metabolism and stress responses. ACSS2 is the only known enzyme that can recycle acetate derived from deacetylation reactions in the cytoplasm and nucleus of cells, including both protein and metabolite deacetylation reactions. As such, ACSS2 can recycle acetate derived from histone deacetylase reactions as well as protein deacetylation reactions mediated by sirtuins, among many others. Notably, ACSS2 can activate acetate released from acetylated metabolites including N-acetylaspartate (NAA), the most concentrated acetylated metabolite in the human brain. NAA has been associated with the metabolic reprograming of cancer cells, where ACSS2 also plays a role. Here, we discuss the context-specific roles that acetate can play in health and disease.

Inhibition Of Monocarboxylate Transporter 1 In Spinal Cord Horn Significantly Reverses Chronic Inflammatory Pain

Purpose

Chronic inflammatory pain is a common condition in the clinic, and the underlying mechanism is not being completely understood. Various studies have demonstrated that central and peripheral sensitization and synaptic plasticity could play crucial functions in chronic inflammatory pain. Moreover, families of monocarboxylate transporters (MCTs) are closely related to cellular metabolism and synaptic plasticity, and it is also reported that MCTs participate in chronic inflammatory pain. Nevertheless, there is a probability of the engaging role of MCT 1 is in chronic inflammatory pain, but its specific cellular level mechanism is yet to be investigated. In our study, we hypothesized that MCT 1 in the spinal dorsal horn plays an important part in chronic inflammatory pain.

Methods

In experiment A, rats were gone through nociceptive behavioral testing at 1 d day before and 1 d, 3 d, and 7 d after completing complete Freund’s adjuvant (CFA) injection. The specimens collected for detecting MCT 1 by Western blotting. In experiment B, rats were randomly divided into four groups. Intrathecal injection of MCT 1 inhibitor and nociceptive behavioral tests were performed 1 d day before and 1 d, 3 d, 7 d, 14 d, and 21 d after CFA injection. MCT 1 and p-ERK levels in spinal dorsal horn were measured by Western blotting, and GFAP in spinal dorsal horn was detected by immunofluorescence.

Results

The expression of MCT 1 in the spinal dorsal horn was increased during chronic inflammatory pain in rats. The intrathecal injection of an MCT 1 inhibitor evidently diminished the expression of MCT 1 and GFAP in the spinal dorsal horn, and the behavioral nociceptive responses were also attenuated. Meanwhile, the expression of p-ERK was also decreased by the intrathecal injection of an MCT 1 inhibitor.

Conclusion

Our results indicate that MCT 1 very likely play a critical role in regulating chronic inflammatory pain and may influence the regulation of synaptic plasticity via ERK in the spinal dorsal horn of rats.