A Novel Combinatorial Regimen Using Sorafenib and Uttroside B, A US FDA-designated 'Orphan Drug', for the Treatment of Hepatocellular Carcinoma.

INTRODUCTION: Sorafenib (Sor) is the first-line treatment option in clinics for treating advanced unresectable hepatocellular carcinoma (HCC). However, acquired chemoresistance and adverse side effects associated with Sor monotherapy limit its clinical benefits. We have previously reported the exceptional anti-HCC potential of uttroside B (Utt-B), a furostanol saponin isolated in our lab from Solanum nigrum Linn. leaves. The current study has evaluated the supremacy of a combinatorial regimen of Sor and Utt-B over Sor monotherapy. METHODS: MTT assay was used for In vitro cytotoxicity studies. A clonogenic assay was conducted to assess the anti-proliferative effect of the combination. Annexin V/PI staining, confocal microscopy, FACS cell cycle analysis, and Western blotting experiments were performed to validate the pro-apoptotic potential of the combination in HepG2 and Huh7 cell lines. Pharmacological safety evaluation was performed in Swiss albino mice. RESULTS: Our results indicate that Utt-B augments Sor-induced cytotoxicity in HepG2 and Huh7 cells. The combination inhibits the proliferation of liver cancer cells by inducing apoptosis through activation of the caspases 7 and 3, leading to PARP cleavage. Furthermore, the combination does not induce any acute toxicity in vivo, even at a dose five times that of the effective therapeutic dose. CONCLUSION: Our results highlight the potential of Utt-B as an effective chemosensitizer, which can augment the efficacy of Sor against HCC and circumvent Sor-induced toxic side effects. Moreover, this is the first and only report to date on the chemosensitizing potential of Utt-B and the only report that demonstrates the therapeutic efficacy and pharmacological safety of a novel combinatorial regimen involving Utt-B and Sor for combating HCC.

Naringin and temozolomide combination suppressed the growth of glioblastoma cells by promoting cell apoptosis: network pharmacology, in-vitro assays and metabolomics based study.

Introduction: Glioblastoma, which affects a large number of patients every year and has an average overall lifespan of around 14.6 months following diagnosis stands out as the most lethal primary invasive brain tumor. Currently, surgery, radiation, and chemotherapy with temozolomide (TMZ) are the three major clinical treatment approaches. However, the ability to treat patients effectively is usually limited by TMZ resistance. Naringin, a bioflavonoid with anti-cancer, antioxidant, metal-chelating, and lipid-lowering effects, has emerged as a promising therapeutic option. Methods: To explore the targets and pathways of naringin and TMZ in glioblastoma network pharmacology, cell line-based ELISA, flow cytometry, immunocytochemistry, western blotting, and LC-HRMS based metabolomics study were used. Results: The findings through the network pharmacology suggested that the key targets of naringin in the chemosensitization of glioblastoma would be Poly [ADP-ribose] polymerase 1 (PARP-1), O-6-Methylguanine-DNA Methyltransferase (MGMT), and caspases. The functional enrichment analysis revealed that these targets were significantly enriched in important pathways such as p53 signaling, apoptosis, and DNA sensing. Further, the results of the in-vitro study in U87-MG and T98-G glioblastoma cells demonstrated that TMZ and naringin together significantly reduced the percentage of viability and inhibited the DNA repair enzymes PARP-1 and MGMT, and PI3K/AKT which led to chemosensitization and, in turn, induced apoptosis, which was indicated by increased p53, caspase-3 expression and decreased Bcl2 expression. Additionally, a metabolomics study in T98-G glioblastoma cells using liquid chromatography high-resolution mass spectrometry (LC-HRMS) revealed downregulation of C8-Carnitine (-2.79), L-Hexanoylcarnitine (-4.46), DL-Carnitine (-2.46), Acetyl-L-carnitine (-3.12), Adenine (-1.3), Choline (-2.07), Propionylcarnitine (-1.69), Creatine (-1.33), Adenosine (-0.84), Spermine (-1.42), and upregulation of Palmitic Acid (+1.03) and Sphingosine (+0.89) in the naringin and TMZ treatment groups. Discussion: In conclusion, it can be said that naringin in combination with TMZ chemosensitized TMZ antiglioma response and induced apoptosis in tumor cells.

Removable Photocatalysis Microneedle Reactor for Carbon Monoxide Delivery to Enhance Chemosensitization.

Carbon monoxide (CO) has emerged as a promising therapeutic agent, yet ensuring safe and precise CO delivery remains challenging. Here, we report a removable hydrogel-forming microneedle (MN) reactor for CO delivery via photocatalysis, with an emphasis on chemosensitization. Upon application, body fluids absorbed by the MNs dissolve the effervescent agents, leading to the generation of carbon dioxide (CO2) and triggering the release of the chemotherapeutics cisplatin. Meanwhile, the photocatalysts (PCs) trapped within MNs convert CO2 to CO under 660 nm light irradiation. These PCs can be removed by hydrogel-forming MNs, thereby mitigating potential biological risks associated with residual PCs. Both in vitro and in vivo experiments showed that MN-mediated CO delivery significantly improved tumor sensitivity to cisplatin by suppressing DNA repair, using an A375/CDDP melanoma model. This removable photocatalysis MN reactor offers safe and precise local delivery of CO, potentially creating new opportunities for CO or its combination therapies.

Anti-Tumor and Chemosensitizing Effects of the CDK Inhibitor Dinaciclib on Cholangiocarcinoma In Vitro and In Vivo.

BACKGROUND/AIM: Cholangiocarcinoma (CCA) is a highly aggressive disease. Most of CCA patients are diagnosed in an advanced stage of the disease, when it is unresectable and there is chemoresistance, resulting in poor prognosis. However, effective therapeutic regimens and molecular targets for CCA remain poor. Cyclin-dependent kinases (CDKs) are key regulatory enzymes in cell cycle progression. Aberrant CDK activation is a hallmark of cancer. Dinaciclib is a small molecule inhibitor of multiple CDKs, currently under clinical evaluation for treating advanced malignancies. The efficacy of anti-tumor activity of dinaciclib against chemotherapy resistant CCA cells was examined in vitro and in vivo. MATERIALS AND METHODS: In this study, the effect of dinaciclib on growth and cell cycle in CCA cell lines were determined using the MTT assay and cell cycle analysis. The anti-tumor activity of dinaciclib was investigated in CCA-inoculated mice. In addition, the chemosensitizing effect of dinaciclib was investigated in gemcitabine-treated CCA cell lines. RESULTS: Dinaciclib significantly suppressed cell proliferation, induced G1/S phase cell cycle arrest and apoptosis of CCA cell lines. It significantly suppressed the growth of CCA cells in xenograft mouse models. We also found that dinaciclib significantly inhibited the growth of gemcitabine-resistant CCA cell lines (KKU-213A-GemR and KKU-100-GemR). Furthermore, dinaciclib significantly enhanced the anti-tumor activity of gemcitabine in CCA cell lines. CONCLUSION: Dinaciclib has the potential to be an effective therapeutic agent to control tumor cell growth of both parental and gemcitabine-resistant CCA cells.

Synergistic enhancement: Exploring the potential of piperine in cancer therapeutics through chemosensitization and combination therapies.

Despite significant advancements in chemotherapy, effective treatments for advanced cancer stages remain largely elusive due to chemoresistance. Resistance to anticancer agents in cancer cells can arise through various mechanisms, including multi-drug resistance, inhibition of apoptosis, modification of drug targets, and enhancement of DNA repair capabilities. Consequently, there is a critical need for agents that can suppress the molecular signatures responsible for drug resistance. Piperine, an active alkaloid extracted from Piper nigrum L. (black pepper), is one such agent that has been extensively studied for its potential in addressing chronic diseases, including cancer. Piperine's antineoplastic properties are mediated through the regulation of numerous key cellular signaling pathways and the modulation of various biological processes. Its capability to enhance drug bioavailability and counteract mechanisms of drug resistance, such as the inhibition of P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP-1), emphasizes its potential as an adjunct in cancer therapy. Research across various cancer types has demonstrated piperine's role in chemosensitization by targeting P-gp and MRP-1 and altering drug-metabolizing enzymes. This review provides a comprehensive analysis of piperine's pharmacological characteristics and its capacity to modulate several cellular signaling pathways involved in drug resistance. Furthermore, the review emphasizes how piperine, when used in conjunction with other chemotherapeutic agents or natural compounds, can enhance therapeutic effects, leading to improved outcomes in cancer treatment.

Solasodine targets NF-κB signaling to overcome P-glycoprotein mediated multidrug resistance in cancer.

P-glycoprotein (P-gp) mediated multidrug resistance (MDR) is the leading cause of chemotherapy failure since it causes the efflux of chemotherapeutic drugs from the cancer cells. Solasodine, a steroidal alkaloid and oxaspiro compound, present in the Solanaceae family showed significant cytotoxic effects on various cancer cells. However, the effect of solasodine on reversing P-gp mediated drug resistance is still unknown. Primarily in this study, the integrative network pharmacology analysis found 71 common targets between solasodine and cancer MDR, among them NF-κB was found as a potential target. The results of immunofluorescence analysis showed that solasodine significantly inhibits NF-κB-p65 nuclear translocation which caused downregulated P-gp expression in KBChR-8-5 cells. Further, solasodine binds to the active sites of the TMD region of P-gp and inhibits P-gp transport activity. Moreover, solasodine significantly promotes doxorubicin intracellular accumulation in the drug resistant cells. Solasodine reduced the fold resistance and synergistically sensitized doxorubicin's therapeutic effects in KBChR-8-5 cells. Additionally, the solasodine and doxorubicin combination treatment increased the apoptotic cell populations and G2/M phase cell cycle arrest in KBChR-8-5 cells. The MDR tumor bearing xenograft mice showed tumor-suppressing characteristics and P-gp downregulation during the combination treatment of solasodine and doxorubicin. These results indicate that solasodine targets NF-κB signaling to downregulate P-gp overexpression, inhibit P-gp transport activity, and enhance chemosensitization in MDR cancer cells. Considering its multifaceted impact, solasodine represents a potent natural fourth-generation P-gp modulator for reversing MDR in cancer.

Chemotherapeutic potential of lupeol against cancer in pre-clinical model: A systematic review and meta-analysis.

BACKGROUND: Extensive research on Lupeol's potential in cancer prevention highlights its ability to target various cancer-related factors. It regulates proliferative markers, modulates signaling pathways, including PI3K/AKT/mTOR, and influences inflammatory and apoptotic mechanisms. Additionally, Lupeol demonstrates selectivity in killing cancer cells while sparing normal cells, thus minimizing the risk of toxic effects on healthy tissues. HYPOTHESIS: Therefore, we aimed to explore Lupeol's potential roles as a chemotherapeutic agent and as a sensitizer to chemotherapy by reviewing various animal-based studies published on its effects. STUDY DESIGN: We conducted a comprehensive search across databases, including PubMed, PMC, Cochrane, EuroPMC, and ctri.gov.in to identify pertinent articles. Our focus was solely on published animal studies examining Lupeol's anti-cancer effects, with reviewers independently assessing bias risk and resolving discrepancies through consensus. RESULT: 20 studies were shortlisted. The results demonstrated that Lupeol brings changes in the tumor volume by [Hedges's g: -6.62; 95 % CI: -8.68, -4.56; τ2: 24.36, I2: 96.50 %; p < 0.05] and tumor weight by [Hedges's g: -3.97; 95 % CI: -5.20, -2.49; τ2: 2.70, I2: 79.27 %; p <0.05]. The high I2, negative Egger's value, and asymmetrical funnel plot show the publication bias among the studies. Further, Lupeol in combination with other chemotherapeutic agents showed better outcomes as compared to them alone [Hedges's g: -6.38; 95 % CI: -11.82, -0.94; τ2: 46.91; I2: 98.68 %; p <0.05]. Lupeol also targets various signaling molecules and pathways to exert an anti-cancer effect. CONCLUSION: In conclusion, Lupeol significantly reduces tumor volume and weight. Combining Lupeol with other chemotherapy agents shows promise for enhancing anti-cancer effects. However, high variability among studies and evidence of publication bias suggest caution in interpreting results.

Red light-activated depletion of drug-refractory glioblastoma stem cells and chemosensitization of an acquired-resistant mesenchymal phenotype.

Glioblastoma stem cells (GSCs) are potent tumor initiators resistant to radiochemotherapy, and this subpopulation is hypothesized to re-populate the tumor milieu due to selection following conventional therapies. Here, we show that 5-aminolevulinic acid (ALA) treatment-a pro-fluorophore used for fluorescence-guided cancer surgery-leads to elevated levels of fluorophore conversion in patient-derived GSC cultures, and subsequent red light-activation induces apoptosis in both intrinsically temozolomide chemotherapy-sensitive and -resistant GSC phenotypes. Red light irradiation of ALA-treated cultures also exhibits the ability to target mesenchymal GSCs (Mes-GSCs) with induced temozolomide resistance. Furthermore, sub-lethal light doses restore Mes-GSC sensitivity to temozolomide, abrogating GSC-acquired chemoresistance. These results suggest that ALA is not only useful for fluorescence-guided glioblastoma tumor resection, but that it also facilitates a GSC drug-resistance agnostic, red light-activated modality to mop up the surgical margins and prime subsequent chemotherapy.

Exploration of the sensitization effect of Chaihu Shugan powder on chemotherapy for triple-negative breast cancer and its active ingredients.

Chemotherapy plays a crucial role in the clinical treatment of triple-negative breast cancer (TNBC), but drug resistance limits its clinical application. The active ingredients of Chaihu Shugan Powder (CSP; Bupleurum Liver-Coursing Powder), quercetin and luteolin, both belong to flavonoid compounds and have significant anti-tumor potential, which can promote chemotherapy sensitivity. However, the correlation between the two and TNBC paclitaxel (PTX) chemotherapy sensitivity is unknown. We collected herbal components of CSP from the TCMSP database, and screened effective molecules and corresponding targets. STRING database was utilized to construct a protein-protein interaction network combining effective molecules and target genes. The top 50 nodes ranked by affinity were chosen for subsequent functional analysis, and the drug-active ingredient-gene interaction network was established using Cytoscape software. Molecular docking was used to determine the small molecules that target TNBC PTX resistance. The "clusterProfiler" package was utilized for GO and KEGG enrichment analyses on the top 50 genes to determine the pathways affected by CSP. Cell counting and colony formation assays evaluated cell viability, IC50 values, and proliferation capacity. Flow cytometry tested PTX intracellular accumulation. Western blot assayed the expression of TNF pathway-related proteins. Active ingredients of CSP, quercetin and luteolin, could inhibit TNBC cell proliferation and promote PTX chemotherapy sensitization. Quercetin and luteolin repressed the TNF signaling pathway and promoted PTX chemotherapy sensitization. Quercetin and luteolin could inhibit TNBC cell proliferation and promote PTX chemotherapy sensitization through the TNF signaling pathway. Therefore, the use of quercetin and luteolin plus PTX treatment provides a prospective strategy for TNBC treatment.

Triple Combinations of Histone Lysine Demethylase Inhibitors with PARP1 Inhibitor-Olaparib and Cisplatin Lead to Enhanced Cytotoxic Effects in Head and Neck Cancer Cells.

PARP inhibitors are used to treat cancers with a deficient homologous recombination (HR) DNA repair pathway. Interestingly, recent studies revealed that HR repair could be pharmacologically impaired by the inhibition of histone lysine demethylases (KDM). Thus, we investigated whether KDM inhibitors could sensitize head and neck cancer cells, which are usually HR proficient, to PARP inhibition or cisplatin. Therefore, we explored the effects of double combinations of KDM4-6 inhibitors (ML324, CPI-455, GSK-J4, and JIB-04) with olaparib or cisplatin, or their triple combinations with both drugs, on the level of DNA damage and apoptosis. FaDu and SCC-040 cells were treated with individual compounds and their combinations, and cell viability, apoptosis, DNA damage, and gene expression were assessed using the resazurin assay, Annexin V staining, H2A.X activation, and qPCR, respectively. Combinations of KDM inhibitors with cisplatin enhanced cytotoxic effects, unlike combinations with olaparib. Triple combinations of KDM inhibitors with cisplatin and olaparib exhibited the best cytotoxic activity, which was associated with DNA damage accumulation and altered expression of genes associated with apoptosis induction and cell cycle arrest. In conclusion, triple combinations of KDM inhibitors (especially GSK-J4 and JIB-04) with cisplatin and olaparib represent a promising strategy for head and neck cancer treatment.

Curcumin and its Analogues in Oral Squamous Cell Carcinoma: State-of-the-art and Therapeutic Potential.

Oral Squamous Cell Carcinoma (OSCC) is the most common cancer arising from squamous epithelium in the oral cavity and is characterized by high aggressiveness and metastatic potential, which together with a late diagnosis results in a 5-year survival rate of only 50% of patients. The therapeutic options for OSCC management are limited and largely influenced by the cancer stage. While radical surgery can be curative in early stage of disease, most cases require adjuvant therapies, including chemotherapy and radiotherapy which, however, often achieve poor curative rates and are associated with important negative effects. Therefore, there is an urgent need to discover new alternative treatment strategies to improve patients' outcomes. Several medicinal herbs are being studied for their preventive or therapeutic effect in several diseases, including cancer. In particular, the Indian spice curcumin, largely used in oriental countries, has been studied as a chemopreventive or adjuvant agent for different malignancies. Indeed, curcumin is characterized by important biological properties, including antioxidant, anti-inflammatory, and anticancer effects, which could also be exploited in OSCC. However, due to its limited bioavailability and poor aqueous solubility, this review is focused on studies designing new synthetic analogues and developing novel types of curcumin delivery systems to improve its pharmacokinetic and biological properties. Thus, this review analyses the potential therapeutic role of curcumin in OSCC by providing an overview of current in vitro and in vivo studies demonstrating the beneficial effects of curcumin and its analogues in OSCC.

New Avenues and Major Achievements in Phytocompounds Research for Glioblastoma Therapy.

Phytocompounds have been evaluated for their anti-glioblastoma actions for decades, with promising results from preclinical studies but only limited translation into clinics. Indeed, by targeting multiple signaling pathways deregulated in cancer, they often show high efficacy in the in vitro studies, but their poor bioavailability, low tumor accumulation, and rapid clearance compromise their efficacy in vivo. Here, we present the new avenues in phytocompound research for the improvement of glioblastoma therapy, including the ways to enhance the response to temozolomide using phytochemicals, the current focus on phytocompound-based immunotherapy, or the use of phytocompounds as photosensitizers in photodynamic therapy. Moreover, we present new, intensively evaluated approaches, such as chemical modifications of phytochemicals or encapsulation into numerous types of nanoformulations, to improve their bioavailability and delivery to the brain. Finally, we present the clinical trials evaluating the role of phytocompounds or phytocompound-derived drugs in glioblastoma therapy and the less studied phytocompounds or plant extracts that have only recently been found to possess promising anti-glioblastoma properties. Overall, recent advancements in phytocompound research are encouraging; however, only with more 3D glioblastoma models, in vivo studies, and clinical trials it is possible to upgrade the role of phytocompounds in glioblastoma treatment to a satisfactory level.

A Monocarbonyl Curcuminoid Derivative Inhibits the Activity of Human Glutathione Transferase A4-4 and Chemosensitizes Glioblastoma Cells to Temozolomide.

Human glutathione transferase A4-4 (hGSTA4-4) displays high catalytic efficiency towards 4-hydroxyalkenals and other cytotoxic and mutagenic products of radical reactions and lipid peroxidation. Its role as a target for the chemosensitization of cancer cells has not been investigated so far. In this study, the inhibitory potency of twelve selected natural products and ten monocarbonyl curcumin derivatives against hGSTA4-4 was studied. Among natural products, ellagic acid turned out to be the strongest inhibitor with an IC50 value of 0.44 ± 0.01 µM. Kinetic analysis using glutathione (GSH) and 1-chloro-2,4-dinitrobenzene (CDNB) as variable substrates showed that ellagic acid behaved as a competitive inhibitor towards both GSH and CDNB, with Ki values of 0.39 ± 0.02 and 0.63 ± 0.03 µM, respectively. Among the curcumin derivatives studied, three proved to be the most potent inhibitors, in the order DM151 > DM101 > DM100, with IC50 values of 2.4 ± 0.1 µM, 12.7 ± 1.1 µΜ and 16.9 ± 0.4 µΜ, respectively. Further kinetic inhibition analysis of the most active derivative, DM151, demonstrated that this compound is a mixed inhibitor towards CDNB with inhibition constants of Ki = 4.1 ± 0.5 µM and Ki' = 0.536 ± 0.034 µM, while it is a competitive inhibitor towards GSH with a Ki = 0.98 ± 0.11 µM. Molecular docking studies were performed to interpret the differences in binding of ellagic acid and curcumin derivatives to hGSTA4-4. The in silico measured docking scores were consistent with the obtained experimental data. Hydrogen bonds appear to be the main contributors to the specific binding of monocarbonyl curcumin derivatives, while π-π stacking interactions play a key role in the enzyme-ellagic acid interaction. In vitro cytotoxicity assessment of the worst (DM148) and the best (DM151) inhibitors was performed against glioblastoma cell lines U-251 MG and U-87 MG. The results revealed that DM151 displays considerably higher cytotoxicity against both glioblastoma cell lines, while the glioblastoma cytotoxicity of DM148 was very limited. Furthermore, low and non-toxic doses of DM151 sensitized U-251 MG cells to the first-line glioblastoma chemotherapeutic temozolomide (TMZ), allowing us to propose for the first time that hGSTA4-4 inhibitors may be attractive therapeutic partners for TMZ to optimize its clinical effect in glioblastoma chemotherapy.

Epidermal growth factor receptor inhibition potentiates chemotherapeutics-mediated sensitization of metastatic breast cancer stem cells.

BACKGROUND: Metastasis has been a cause of the poor prognosis and cancer relapse of triple-negative breast cancer (TNBC) patients. The metastatic nature of TNBC is contributed by the breast cancer stem cells (CSCs) which have been implicated in tumorigenesis. Higher expression of epidermal growth factor receptor (EGFR) in breast CSCs has been used as a molecular target for breast cancer therapeutics. Thus, it necessitates the design and generation of efficacious EGFR inhibitors to target the downstream signaling associated with the cellular proliferation and tumorigenesis of breast cancer. AIM: To generate efficacious EGFR inhibitors that can potentiate the chemotherapeutic-mediated mitigation of breast cancer tumorigenesis. METHODS AND RESULTS: We identified small molecule EGFR inhibitors using molecular docking studies. In-vitro screening of the compounds was undertaken to identify the cytotoxicity profile of the small-molecule EGFR inhibitors followed by evaluation of the non-cytotoxic compounds in modulating the doxorubicin-induced migration, in-vitro tumorigenesis potential, and their effect on the pro-apoptotic genes' and protein markers' expression in TNBC cells. Compound 1e potentiated the doxorubicin-mediated inhibitory effect on proliferation, migration, in-vitro tumorigenesis capacity, and induction of apoptosis in MDA-MB-231 cells, and in the sorted CD24+-breast cancer cells and CD24-/CD44+-breast CSC populations. Orthotopic xenotransplantation of the breast CSCs-induced tumors in C57BL/6J mice was significantly inhibited by the low dose of Doxorubicin in the presence of compound 1e as depicted by molecular and immunohistochemical analysis. CONCLUSION: Thus, the study suggests that EGFR inhibition-mediated sensitization of the aggressive and metastatic breast CSCs in TNBCs toward chemotherapeutics may reduce the relapse of the disease.

Anti-proliferative, Pro-apoptotic, and Chemosensitizing Potential of 3-Acetyl-11-keto-ß-boswellic Acid (AKBA) Against Prostate Cancer Cells.

Prostate cancer incidences are rising worldwide at an alarming rate. Drug resistance and relapse are two major challenges in the treatment of prostate cancer. Therefore, new multimodal, safe, and effective therapeutic agents are urgently required which could effectively mitigate the menace of tumor recurrence and chemo-resistance. Plant-derived products are increasingly being utilized due to their antioxidant, antibacterial, and anti-tumor potential. In the current study, 3-acetyl-11-keto-ß-boswellic acid, a triterpenoid isolated from plant Boswellia, was utilized to ascertain its chemotherapeutic potential against human prostate cancer cells. Various in vitro assays including cell viability, nuclear staining, mitochondria potential, reactive oxygen species (ROS) generation, and quantification of apoptosis, were performed for the evaluation of the cytotoxic potential of AKBA. We observed that AKBA (10-50 µM) dose-dependently suppressed cell proliferation and caused programmed cell death in PC3 cells via both intrinsic and extrinsic pathway. Intriguingly, AKBA was also found to chemosensitize PC3 cells in synergistic combination with doxorubicin. To the best of our knowledge, this is the first study to document the synergistic chemosensitizing impact of AKBA when combined with doxorubicin in prostate cancer cells.This showcases the potential of AKBA in combinatorial therapy or adjuvant therapy for the management of prostate cancer. In sum, our results suggested that AKBA is a promising drug-like molecule against prostate cancer. Our investigation introduces a novel perspective, elucidating a previously unexplored dimension, and uncovering a compelling chemosensitizing phenomenon along with a strong synergistic effect arising from the concurrent application of these two agents.

Synergistic effects of epoxyazadiradione (EAD) and paclitaxel against triple-negative breast cancer cells.

BACKGROUND: Triple-negative breast cancer (TNBC) is the most aggressive and chemo-resistant form of breast cancer subtype, and chemotherapy is a vital treatment option for that. Paclitaxel is an effective chemo drug for TNBC. However, in clinical settings, paclitaxel has adverse side effects. The synergistic combination is the most promising method for overcoming undesirable toxicity and achieving a beneficial therapeutic outcome. Previous reports, including our study, showed certain anticancer potential of epoxyazadiradione (EAD), the neem limonoid, in different types of cancer cells, including TNBC. OBJECTIVE: This study was designed to investigate the possible synergistic effects of EAD and paclitaxel against TNBC cells. METHODS: We examined the effects of EAD and paclitaxel alone and in combination in MDA-MB 231 cells, and the percentage cytotoxicity was used to calculate synergism. Characteristic apoptotic changes were observed by visualizing cellular morphology, nuclear fragmentation and membrane integrity. We further estimated anti-migratory potential of experimental compounds by wound healing assay. The reduction in inflammation during combinatorial treatment was evaluated by observing NF-κB translocation. RESULTS: The combined treatment with EAD (5 µM) and paclitaxel (5 nM), which were used at doses lower than their individual IC50 concentrations, showed a synergistic effect in MDA-MB-231 cells. This combination effectively induced apoptosis and antimigration and reduced the inflammatory reactions induced by the higher dose of paclitaxel. CONCLUSION: To conclude, EAD could be the drug of choice for combined treatment with paclitaxel in a chemotherapy regimen.

Therapeutic potential of tocotrienols as chemosensitizers in cancer therapy.

Chemoresistance is the adaptation of cancer cells against therapeutic agents. When exhibited by cancer cells, chemoresistance helps them to avoid apoptosis, cause relapse, and metastasize, making it challenging for chemotherapeutic agents to treat cancer. Various strategies like dosage modification of drugs, nanoparticle-based delivery of chemotherapeutics, antibody-drug conjugates, and so on are being used to target and reverse chemoresistance, one among such is combination therapy. It uses the combination of two or more therapeutic agents to reverse multidrug resistance and improve the effects of chemotherapy. Phytochemicals are known to exhibit chemosensitizing properties and are found to be effective against various cancers. Tocotrienols (T3) and tocopherols (T) are natural bioactive analogs of vitamin E, which exhibit important medicinal value and potential curative properties apart from serving as an antioxidant and nutrient supplement. Notably, T3 exhibits a variety of pharmacological activities like anticancer, anti-inflammatory, antiproliferative, and so on. The chemosensitizing property of tocotrienol is exhibited by modulating several signaling pathways and molecular targets involved in cancer cell survival, proliferation, invasion, migration, and metastasis like NF-κB, STATs, Akt/mTOR, Bax/Bcl-2, Wnt/ß-catenin, and many more. T3 sensitizes cancer cells to chemotherapeutic drugs including cisplatin, doxorubicin, and paclitaxel increasing drug concentration and cytotoxicity. Discussed herewith are the chemosensitizing properties of tocotrienols on various cancer cell types when combined with various drugs and biological molecules.

Chemosensitization of non-small cell lung cancer to sorafenib via non-hydroxamate s-triazinedione-based MMP-9/10 inhibitors.

Non-small cell lung cancer (NSCLC) continues to be a leading cause of cancer death. Its fatality is associated with angiogenesis and metastasis. While VEGFR inhibitors are expected to be the central pillar for halting lung cancer, several clinical reports declared their subpar activities as monotherapy. These results directed combination studies of VEGFR inhibitors, especially sorafenib (Nexavar®), with various chemotherapeutic agents. Matrix metalloproteinase (MMP) inhibitors are seldom utilized in such combinations despite the expected complementary therapeutic outcome. This could be attributed to the clinical unsuitability of MMP inhibitors from the hydroxamate family. Herein, we report new non-hydroxamate s-triazinedione-based inhibitors of MMP-9 (6b; IC50 = 0.112 µM), and MMP-10 (6e; IC50 = 0.076 µM) surpassing the hydroxamate inhibitor NNGH for chemosensitization of NSCLC to sorafenib. MMPs inhibition profiling of the hits revealed MMP-9 over -2 and MMP-10 over -13 selectivity. 6b and 6e were potent (IC50 = 0.139 and 0.136 µM), safe (SI up to 6.77) and superior to sorafenib (IC50 = 0.506 µM, SI = 6.27) against A549 cells. When combined with sorafenib, the studied MMP inhibitors enhanced its cytotoxic efficacy up to 26 folds as confirmed by CI and DRI values for 6b (CI = 0.160 and DRI = 22.175) and 6e (CI = 0.096 and DRI = 29.060). 6b and 6e exerted anti-invasive activities in A549 cells as single agents (22.66 and 39.67 %) and in sorafenib combinations (29.96 and 91.83 %) compared to untreated control. Both compounds downregulated VEGF in A549 cells by approximately 70 % when combined with sorafenib, highlighting enhanced anti-angiogenic activities. Collectively, combinations of 6b and 6e with sorafenib demonstrated synergistic NSCLC cytotoxicity with pronounced anti-invasive and anti-angiogenic activities introducing a promising start point for preclinical studies.

Phytochemicals as Potential Lead Molecules against Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the most prevalent form of liver cancer, accounting for 85-90% of liver cancer cases and is a leading cause of cancer-related mortality worldwide. The major risk factors for HCC include hepatitis C and B viral infections, along with chronic liver diseases, such as cirrhosis, fibrosis, and non-alcoholic steatohepatitis associated with metabolic syndrome. Despite the advancements in modern medicine, there is a continuous rise in the annual global incidence rate of HCC, and it is estimated to reach >1 million cases by 2025. Emerging research in phytomedicine and chemotherapy has established the anti-cancer potential of phytochemicals, owing to their diverse biological activities. In this review, we report the major phytochemicals that have been explored in combating hepatocellular carcinoma and possess great potential to be used as an alternative or in conjunction with the existing HCC treatment modalities. An overview of the pre-clinical observations, mechanism of action and molecular targets of some of these phytochemicals is also incorporated.

SN-38, an active metabolite of irinotecan, inhibits transcription of nuclear factor erythroid 2-related factor 2 and enhances drug sensitivity of colorectal cancer cells.

Nuclear factor erythroid 2-related factor 2 (Nrf2) significantly contributes to drug resistance of cancer cells, and Nrf2 inhibitors have been vigorously pursued. Repurposing of existing drugs, especially anticancer drugs, is a straightforward and promising strategy to find clinically available Nrf2 inhibitors and effective drug combinations. Topoisomerase inhibitors SN-38 (an active metabolite of irinotecan), topotecan, mitoxantrone, and epirubicin were found to significantly suppress Nrf2 transcriptional activity in cancer cells. SN-38, the most potent one among them, significantly inhibited the transcription of Nrf2, as indicated by decreased mRNA level and binding of RNA polymerase II to NFE2L2 gene, while no impact on Nrf2 protein or mRNA degradation was observed. SN-38 synergized with Nrf2-sensitive anticancer drugs such as mitomycin C in killing colorectal cancer cells, and irinotecan and mitomycin C synergistically inhibited the growth of SW480 xenografts in nude mice. Our study identified SN-38 and three other topoisomerase inhibitors as Nrf2 inhibitors, revealed the Nrf2-inhibitory mechanism of SN-38, and indicate that clinically feasible drug combinations could be designed based on their interactions with Nrf2 signaling.