Molecular insights to therapeutic in cancer: role of exosomes in tumor microenvironment, metastatic progression and drug resistance.

Exosomes play a pivotal part in cancer progression and metastasis by transferring various biomolecules. Recent research highlights their involvement in tumor microenvironment remodeling, mediating metastasis, tumor heterogeneity and drug resistance. The unique cargo carried by exosomes garners the interest of researchers owing to its potential as a stage-specific biomarker for early cancer detection and its role in monitoring personalized treatment. However, unanswered questions hinder a comprehensive understanding of exosomes and their cargo in this context. This review discusses recent advancements and proposes novel ideas for exploring exosomes in cancer progression, aiming to deepen our understanding and improve treatment approaches.

Evodiamine potentiates cisplatin-induced cell death and overcomes cisplatin resistance in non-small-cell lung cancer by targeting SOX9-ß-catenin axis.

BACKGROUND: In recent decades, phytotherapy has remained as a key therapeutic option for the treatment of various cancers. Evodiamine, an excellent phytocompound from Evodia fructus, exerts anticancer activity in several cancers by modulating drug resistance. However, the role of evodiamine in cisplatin-resistant NSCLC cells is not clear till now. Therefore, we have used evodiamine as a chemosensitizer to overcome cisplatin resistance in NSCLC. METHODS: Here, we looked into SOX9 expression and how it affects the cisplatin sensitivity of cisplatin-resistant NSCLC cells. MTT and clonogenic assays were performed to check the cell proliferation. AO/EtBr and DAPI staining, ROS measurement assay, transfection, Western blot analysis, RT-PCR, Scratch & invasion, and comet assay were done to check the role of evodiamine in cisplatin-resistant NSCLC cells. RESULTS: SOX9 levels were observed to be higher in cisplatin-resistant A549 (A549CR) and NCI-H522 (NCI-H522CR) compared to parental A549 and NCI-H522. It was found that SOX9 promotes cisplatin resistance by regulating ß-catenin. Depletion of SOX9 restores cisplatin sensitivity by decreasing cell proliferation and cell migration and inducing apoptosis in A549CR and NCI-H522CR. After evodiamine treatment, it was revealed that evodiamine increases cisplatin-induced cytotoxicity in A549CR and NCI-H522CR cells through increasing intracellular ROS generation. The combination of both drugs also significantly inhibited cell migration by inhibiting epithelial to mesenchymal transition (EMT). Mechanistic investigation revealed that evodiamine resensitizes cisplatin-resistant cells toward cisplatin by decreasing the expression of SOX9 and ß-catenin. CONCLUSION: The combination of evodiamine and cisplatin may be a novel strategy for combating cisplatin resistance in NSCLC.

Enigmatic exosomal connection in lung cancer drug resistance.

Lung cancer remains a significant global health concern with limited treatment options and poor prognosis, particularly in advanced stages. Small extracellular vesicles such as exosomes, secreted by cancer cells, play a pivotal role in mediating drug resistance in lung cancer. Exosomes have been found to facilitate intercellular communication by transferring various biomolecules between cancer cells and their microenvironment. Additionally, exosomes can transport signaling molecules promoting cancer cell survival and proliferation conferring resistance to chemotherapy. Moreover, exosomes can modulate the tumor microenvironment by inducing phenotypic changes hindering drug response. Understanding the role of exosomes in mediating drug resistance in lung cancer is crucial for developing novel therapeutic strategies and biomarkers to overcome treatment limitations. In this review, we summarize the current knowledge on conventional and emerging drug resistance mechanisms and the involvement of exosomes as well as exosome-mediated factors mediating drug resistance in lung cancer.

Transforming native exosomes to engineered drug vehicles: A smart solution to modern cancer theranostics.

Exosomes have been the hidden treasure of the cell in terms of cellular interactions, transportation and therapy. The native exosomes (NEx) secreted by the parent cells hold promising aspects in cancer diagnosis and therapy. NEx has low immunogenicity, high biocompatibility, low toxicity and high stability which enables them to be an ideal prognostic biomarker in cancer diagnosis. However, due to heterogeneity, NEx lacks specificity and accuracy to be used as therapeutic drug delivery vehicle in cancer therapy. Transforming these NEx with their innate structure and multiple receptors to engineered exosomes (EEx) can provide better opportunities in the field of cancer theranostics. The surface of the NEx exhibits numeric receptors which can be modified to pave the direction of its therapeutic drug delivery in cancer therapy. Through surface membrane, EEx can be modified with increased drug loading potentiality and higher target specificity to act as a therapeutic nanocarrier for drug delivery. This review provides insights into promising aspects of NEx as a prognostic biomarker and drug delivery tool along with its need for the transformation to EEx in cancer theranostics. We have also highlighted different methods associated with NEx transformations, their nano-bio interaction with recipient cells and major challenges of EEx for clinical application in cancer theranostics.

Exposure of piperlongumine attenuates stemness and epithelial to mesenchymal transition phenotype with more potent anti-metastatic activity in SOX9 deficient human lung cancer cells.

Phytocompounds have shown hopeful results in cancer therapy. Piperlongumine (PIP), a naturally derived bioactive alkaloid found in our dietary spice, exhibits promising pharmacological relevance including anticancer activity. This study reconnoitred the anti-lung cancer effect of PIP and the allied mechanisms, in vitro and ex vivo. The cytotoxic, anti-proliferative, and apoptotic effects of PIP on lung cancer cells (LCC) were checked via cell viability, colony formation, cell migration, invasion, comet assay, and various staining techniques. Further, multicellular spheroids assay explored the anti-lung cancer potential of PIP, ex vivo. Preliminary results explored that PIP exerts selective cytotoxic and anti-proliferative effects on LCC by DNA damage and cell cycle arrest. PIP remarkably escalated the cellular and mitochondrial reactive oxygen species (ROS) generation and promoted dissipation of mitochondrial membrane potential (MMP), which triggers activation of caspase-dependent apoptotic pathway in LCC. Mechanistically, PIP showed F-actin deformation mediated significant anti-migratory and anti-invasive activity against LCC. Herein, we also found that F-actin dis-organization modulates the expression of epithelial to mesenchymal transition (EMT) markers and inhibits the expression of stemness marker proteins, like SOX9, CD-133, and CD-44. Moreover, PIP effectively reduced the size of spheroids with strong apoptotic and cytotoxic effects, ex vivo. This has been the first study to discover the high expression of SOX9 supporting the survival of LCC, whereas its inhibition induces higher sensitivity to PIP treatment. This study concludes a newer therapeutic agent (PIP) with promising anticancer activity against LCC by escalating ROS and attenuating MMP, stemness, and EMT.

Tumour microenvironment and aberrant signaling pathways in cisplatin resistance and strategies to overcome in oral cancer.

OBJECTIVE: Oral cancer is the sixteenth most prevalent cancer in the world and the third-most in India. Despite of several treatment modalities, the cure rate of oral cancer is still low due to drug resistance mechanisms, which are caused by many reasons. It is necessary to improve the existing treatment strategies and discover neoteric therapy to kill cancer cells, which will give oral cancer's cure rate more success. So this review aims to delineate the molecular mechanisms behind cisplatin resistance, specifically the role of the tumor microenvironment, extracellular vesicles, and altered signaling pathways and its overcoming strategies in oral cancer. DESIGN: This review was designed by searching words like cancer, oral cancer, cisplatin-resistance, tumor microenvironment, aberrant signalings, and extracellular vesicles, overcoming strategies for cisplatin resistance in databases like PubMed, Google Scholar, web science, and Scopus. Data available in this review is from 2017 to 2021. RESULTS: After searching too much data, we found these 98 data appropriate for our review. From these data, we found that tumor microenvironment, extracellular vesicles, and altered signaling pathways like PI3K/AKT, EGFR, NOTCH, Ras, PTEN, Nf-κß, and Wnt signaling have a crucial role in resistance development towards cisplatin in oral cancer. CONCLUSIONS: Lastly, this review explores the alternative strategies to overcome cisplatin resistance likely, the combination therapy and targeted therapy by combining more than one chemotherapeutic drug or inhibitors of signaling pathways and also by using nanoparticle loaded drugs that will reduce the drug efflux, which gives new treatment strategies.

Evodiamine as an anticancer agent: a comprehensive review on its therapeutic application, pharmacokinetic, toxicity, and metabolism in various cancers.

Evodiamine is a major alkaloid component found in the fruit of Evodia rutaecarpa. It shows the anti-proliferative potential against a wide range of cancers by suppressing cell growth, invasion, and metastasis and inducing apoptosis both in vitro and in vivo. Evodiamine shows its anticancer potential by modulating aberrant signaling pathways. Additionally, the review focuses on several therapeutic implications of evodiamine, such as epigenetic modification, cancer stem cells, and epithelial to mesenchymal transition. Moreover, combinatory drug therapeutics along with evodiamine enhances the anticancer efficacy of chemotherapeutic drugs in various cancers by overcoming the chemo resistance and radio resistance shown by cancer cells. It has been widely used in preclinical trials in animal models, exhibiting very negligible side effects against normal cells and effective against cancer cells. The pharmacokinetic and pharmacodynamics-based collaborations of evodiamine are also included. Due to its poor bioavailability, synthetic analogs of evodiamine and its nano capsule have been formulated to enhance its bioavailability and reduce toxicity. In addition, this review summarizes the ongoing research on the mechanisms behind the antitumor potential of evodiamine, which proposes an exciting future for such interests in cancer biology.

Synthesis of First Coumarin Fluorescent Dye for Actin Visualization.

Selective fluorescence imaging of actin protein hugely depends on the fluorescently labeled actin-binding domain (ABD). Thus, it is always a challenging task to image the actin protein (in vivo or in vitro) directly with an ABD-free system. To overcome the limitations of actin imaging without an ABD, we have designed a facile and cost-effective red fluorescent coumarin dye 7-hydroxy-4-methyl-8-(4-(2-oxo-2H-chromen-3-yl)thiazol-2-ylimino)methyl-2H-chromen-2-one (CTC) for actin binding. The selective binding of the dye was investigated using the gut and eye of the model organism Drosophila melanogaster and C2C12 and SCC-9 cell lines. Our result suggests two major advantages of CTC over the dyes presently used for imaging actin proteins. First, the dye can bind to actin efficiently without any secondary intermediate. Second, it is much more stable at room temperature and exhibits excellent photostability. To the best of our knowledge, this is the first fluorescent dye that can bind to the actin protein without employing any secondary intermediate/actin-binding domain. These findings could pave the way for many biologists and physicists to successfully employ the CTC dye for imaging and tracking actin proteins by fluorescence microscopy in various in vivo and in vitro systems.

Evodiamine inhibits stemness and metastasis by altering the SOX9-ß-catenin axis in non-small-cell lung cancer.

Evodiamine (EVO), a natural dietary alkaloid extracted from the roots of the Evodia rutaecarpa, has shown anticancer activities. Here, we have investigated EVO's role in inhibiting cell proliferation and migration in A549 and NCI-H522 lung cancer cells. EVO decreased the cell viability in A549 and NCI-H522 cells in a dose- and time-dependent manner. It also induced apoptosis by downregulating the expression of antiapoptotic Bcl-2 and upregulating the expression of cleaved caspase-3 and PARP. In addition, the treatment of EVO elevated the level of reactive oxygen species (ROS) generation inside the cells to induce the cell death pathways. In contrast, the pretreatment of ROS scavenger, N-acetyl cysteine, reverses the effect of EVO and attenuates cell death. Moreover, excess ROS generation in response to EVO resulted in the depletion of mitochondrial membrane potential. Furthermore, it induced DNA damage and arrested the cell cycle at the G2/M phase in A549 and NCI-H522 cells. Our study also investigated that EVO significantly suppressed tumorigenicity by inhibiting colony formation and tumorsphere formation. However, the treatment of EVO downregulated the cancer stem cell markers CD44 and CD133 in non-small-cell lung cancer. The inhibitory effect of EVO on cell invasion was mediated by altering the expression of E-cadherin, ZO-1, N-cadherin, and Vimentin. Additionally, we have revealed that EVO treatment showed downregulation of SOX9, an upstream component of ß-catenin. Lastly, we have demonstrated that EVO targets the SOX9-ß-catenin axis by reducing SOX9 and ß-catenin expression. These findings suggested that EVO could be a promising agent for treating human lung cancer.

SOX9 as an emerging target for anticancer drugs and a prognostic biomarker for cancer drug resistance.

The dysregulated expression of the transcription factor (TF) Sry-related HMG box 9 (SOX9) has been extensively correlated with various biological effects, including the initiation and progression of cancer. Differential expression of SOX9 has been positively correlated with cancer cell growth, invasion, migration, metastasis, and therapy resistance. Studies showed that expression of SOX9 affects the expression of various miRNAs and vice versa, resulting in the development of cancer drug resistance. However, modulating the expression of SOX9 reverses drug resistance by modulating the expression of miRNAs. Therefore, in this review, we summarize current research focusing on SOX9 as a cancer therapeutic target and a prognostic biomarker of cancer drug resistance.

SOX9 promotes epidermal growth factor receptor-tyrosine kinase inhibitor resistance via targeting ß-catenin and epithelial to mesenchymal transition in lung cancer.

AIMS: The first-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), gefitinib, continues to be a primary treatment option for lung cancer patients. However, acquisition of resistance to gefitinib is a major obstacle in lung cancer treatment and its cause is poorly understood. The present study aimed to implicate the role of SOX9-ß-catenin in developed resistance to gefitinib through epithelial to mesenchymal transition (EMT) in lung cancer in vitro and ex vivo. MAIN METHODS: Expression effect of SOX9 on survivability of lung cancer patients was demonstrated through online available Kaplan-Meier Plotter data base. Then, cell viability assay, colony forming assay, cell migration and invasion assays, flow cytometry, drug efflux assay, qRT-PCR, and western blotting were conducted to confirmed the role of SOX9 in gefitinib resistance in lung cancer cells. Dual-luciferase assay established the regulatory relation between SOX9 and ß-catenin. Multicellular spheroid assay further explored that down regulation of SOX9 could reverse gefitinib resistance ex vivo. KEY FINDINGS: Kaplan-Meier method correlated the higher expression of SOX9 and ß-catenin with poor overall survival of lung cancer patients. Upregulation of SOX9 was associated gefitinib resistance with increased cell proliferation, migration and invasion, single-cell colony-forming ability, reduced apoptosis, and gefitinib intake in lung cancer cells. Moreover, upregulated SOX9 promoted EMT via targeting ß-catenin and knockdown of SOX9 reversed the resistance and EMT phenotype. Similarly, we found that multicellular spheroid of gefitinib resistant cells showed larger surface area with more dispersion and viability of cells, while SOX9 knockdown abolished these induced properties ex vivo. SIGNIFICANCE: SOX9 expression could provide an innovative perspective as biomarker to understand the EGFR-TKIs resistance in lung cancer.

Allosteric mutant-selective fourth-generation EGFR inhibitors as an efficient combination therapeutic in the treatment of non-small cell lung carcinoma.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) show most preferable treatment for non-small cell lung carcinoma (NSCLC) with EGFR activating mutations. Despite initial impressive response of first-, to third-generation EGFR-TKIs, these agents become ineffective because of rapid emergence of EGFR mutations (T790M or C797S) mediated resistance. Allosteric mutant-selective fourth-generation EGFR inhibitors appeared to be possible therapeutic option to overcome resistance. These EGFR inhibitors are less effective as a single agent but provide synergistic effect as a combinatorial drug with conventional chemo- or immunotherapeutic. Here, we aim to highlight the comprehensive overview on combined therapeutic efficacy of allosteric EGFR inhibitors for the treatment of EGFR mutant NSCLC.

SOX9: An emerging driving factor from cancer progression to drug resistance.

Dysregulation of transcription factors is one of the common problems in the pathogenesis of human cancer. Among them, SOX9 is one of the critical transcription factors involved in various diseases, including cancer. The expression of SOX9 is regulated by microRNAs (miRNAs), methylation, phosphorylation, and acetylation. Interestingly, SOX9 acts as a proto-oncogene or tumor suppressor gene, relying upon kinds of cancer. Recent studies have reported the critical role of SOX9 in the regulation of the tumor microenvironment (TME). Additionally, activation of SOX9 signaling or SOX9 regulated signaling pathways play a crucial role in cancer development and progression. Accumulating evidence also suggests that SOX9 acquires stem cell features to induce epithelial-mesenchymal transition (EMT). Moreover, SOX9 has been broadly studied in the field of cancer stem cell (CSC) and EMT in the last decades. However, the link between SOX9 and cancer drug resistance has only recently been discovered. Furthermore, its differential expression could be a potential biomarker for tumor prognosis and progression. This review outlined the various biological implications of SOX9 in cancer progression and cancer drug resistance and elucidated its signaling network, which could be a potential target for designing novel anticancer drugs.

Electroformation of liposomes and phytosomes using copper electrode.

A novel method for electroformation of liposomes and phytosomes using copper electrode is described. Liposomes made at 2 V and 10 Hz AC field from L-α-egg-phosphatidylcholine (egg-PC), K. pneumoniae phosphatidylethanolamine, K. pneumoniae polar lipids and E. coli polar lipids on copper electrode were (777.9 ± 118.4), (370.2 ± 100.5), (825.3 ± 21.54), and (281.3 ± 42.3) nm in diameter, respectively. Giant vesicles were formed at 30 V and 10 Hz AC field from polar lipids of K. pneumoniae and E. coli were (106 ± 29.7) and (86 ± 24.3) µm in diameter, respectively. All liposomes were unilamellar as indicated by their unilamellar indices of 50 ± 2, had surface charge comparable to vesicles made from lipid(s) with similar composition and exhibited only 1-2 mol% of oxidized lipids. Cu concentration in the liposomal samples was <1.5 ppm for large unilamellar vesicles (LUVs) and ˂5 ppm for giant unilamellar vesicles (GUVs). The vesicles were stable for >15 d without loss of their size, charge, or unilamellarity. The method was successfully applied to prepare phytosomes from egg-PC and a phytochemical fraction of Dimorphocalyx glabellus, a medicinal plant with anti-diuretic properties. Phytosomes formed were 1000-1500 nm in diameter and exhibited altered fluorescence and absorbance properties compared to the unencapsulated phytochemical. Phytosomes with phytochemical: egg-PC ratio from 0.15 to 1.5 had encapsulation efficiency ranging 90-30%, respectively, and was stable for 1 month. Our method is easy, inexpensive and convenient that will prove to be useful for preparation of liposomes and phytosomes.

Recent updates on the resistance mechanisms to epidermal growth factor receptor tyrosine kinase inhibitors and resistance reversion strategies in lung cancer.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have led to a substantial improvement in the prognosis of lung cancer patients by explicitly targeting the activating mutations within the EGFR. Initially, patients harboring tumors with EGFR mutations show progression-free survival and improvement in the response rates toward all-generation EGFR-TKIs; however, these agents fail to deliver the intended results in the long-term due to drug resistance. Therefore, it is necessary to recognize specific cardinal mechanisms that regulate the resistance phenomenon. Understanding the intricate mechanisms underlying EGFR-TKIs resistance in lung cancer could provide cognizance for more advanced targeted therapeutics. The present review features insights into current updates on the discrete mechanisms, including secondary or tertiary mutations, parallel and downstream signaling pathways, acquiring an epithelial-to-mesenchymal transition (EMT) signature, microRNAs (miRNAs), and epigenetic alterations, which lead to intrinsic and acquired resistance against EGFR-TKIs in lung cancer. In addition, this paper also reviews current possible strategies to overcome this issue using combination treatment of recently developed MET inhibitors, allosteric inhibitors or immunotherapies, transformation of EMT, targeting miRNAs, and epigenetic alterations in intrinsic and acquired EGFR-TKIs resistant lung cancer. In conclusion, multiple factors are responsible for intrinsic and acquired resistance to EGFR-TKIs and understanding of the detailed molecular mechanisms, and recent advancements in pharmacological studies are needed to develop new strategies to overcome intrinsic and acquired EGFR-TKIs resistance in lung cancer.

Plumbagin promotes mitochondrial mediated apoptosis in gefitinib sensitive and resistant A549 lung cancer cell line through enhancing reactive oxygen species generation.

Plumbagin (PL) is a natural naphthoquinone compound, isolated from Plumbago zeylanica that has cytotoxic and antimigratory potential in many cancer. However, the cytotoxic mechanism of plumbagin in drug resistant lung cancer is poorly understood. To reveal the mechanism, we studied the anticancer effect of plumbagin in both gefitinib-sensitive and resistant A549 lung cancer cells. The anticancer potential of PL was demonstrated by MTT assay and the result suggested that PL showed cytotoxicity in both gefitinib-sensitive (A549) and gefitinib-resistant (A549GR) lung cancer cells. IC50 values of PL in A549 and A549GR were 3.2 µM and 4.5 µM, respectively. Morphological changes were also observed after treatment with PL. Furthermore, PL decreased cell survival by inhibiting colony formation ability, and inhibited cell migration at very low concentrations. From Annexin V-FITC/PI, AO/EtBr, and DAPI staining, we found that increasing concentration of PL leads to increase in apoptosis of lung cancer cells. Furthermore, western blotting results suggested that Bax and Caspase 3 levels were upregulated after PL treatment. In addition, treatment of PL caused DNA damage in a dose-dependent manner. PL arrested the cell cycle at S-G2/M phase, and enhanced reactive oxygen species (ROS) generation. Excess ROS generated by PL disrupted mitochondrial membrane resulted in depletion of mitochondrial membrane potential (MMP). These results conclude that PL decreases lung cancer cell viability by arresting cells at S-G2/M phase, and induces apoptosis by activation of mitochondrial-mediated apoptotic pathway through excess ROS generation. Overall findings suggest that plumbagin shows cytotoxic and therapeutic potential against both A549 and A549GR cell lines.

Piperlongumine, a potent anticancer phytotherapeutic: Perspectives on contemporary status and future possibilities as an anticancer agent.

Piperlongumine, a white to beige biologically active alkaloid/amide phytochemical, has high pharmacological relevance as an anticancer agent. Piperlongumine has several biological activities, including selective cytotoxicity against multiple cancer cells of different origins at a preclinical level. Several preclinical studies have documented the anticancer potential of piperlongumine through its targeting of multiple molecular mechanisms, such as cell cycle arrest, anti-angiogenesis, anti- invasive and anti-metastasis pathways, autophagy pathways, and intrinsic apoptotic pathways in vitro and in vivo. Mechanistically, piperlongumine inhibits cancer growth by resulting in the accumulation of intracellular reactive oxygen species, decreasing glutathione and chromosomal damage, or modulating key regulatory proteins, including PI3K, AKT, mTOR, NF-kß, STATs, and cyclin D1. Furthermore, combined treatment with piperlongumine potentiates the anticancer activity of conventional chemotherapeutics and overcomes resistance to chemo- and radio- therapy. Nanoformulation of piperlongumine has been associated with increased aqueous solubility and bioavailability and lower toxicity, thus enhancing therapeutic efficacy in both preclinical and clinical settings. The current review highlights anticancer studies on the occurrence, chemical properties, chemopreventive mechanisms, toxicity, bioavailability, and pharmaceutical relevance of piperlongumine in vitro and in vivo.

Plumbagin engenders apoptosis in lung cancer cells via caspase-9 activation and targeting mitochondrial-mediated ROS induction.

Plumbagin is a naturally-derived phytochemical which exhibits promising medicinal properties, including anticancer activities. In the present study, the anticancer potential of plumbagin has been demonstrated in lung cancer cells by targeting reactive oxygen species (ROS) and the intrinsic mitochondrial apoptotic pathway. Plumbagin showed impressive cytotoxic, anti-proliferative, and anti-migratory activities with IC50 3.10 ± 0.5 µM and 4.10 ± 0.5 µM in A549 and NCI-H522 cells, respectively. Plumbagin treatment significantly reduced the size of A549 tumor spheroids in a concentration-dependent manner. Plumbagin enhanced ROS production and arrested lung cancer cells in S and G2/M phase. Expression of antioxidant genes such as glutathione S-transferase P1 and superoxide dismutase-2 were found to be upregulated with plumbagin treatment in A549 cells. Plumbagin induced dissipation in mitochondrial membrane potential and affected the expression of intrinsic apoptotic pathway proteins. Increased expression of cytochrome c promotes the activation of pro-apoptotic protein Bax with decreased expression of anti-apoptotic protein Bcl-2. Further, plumbagin activated the mitochondrial downstream pathway protein caspase-9 and caspase-3 leading to apoptosis of A549 cells. Collectively, plumbagin could be a promising future phytotherapeutic candidate for lung cancer treatment via targeting intrinsic mitochondrial apoptotic pathway and ROS.

Prooxidative activity of plumbagin induces apoptosis in human pancreatic ductal adenocarcinoma cells via intrinsic apoptotic pathway.

Prognosis of pancreatic cancer patients remains extremely poor thus, the need for the development of new therapeutic options is crucial. Plumbagin, a naphthoquinone derivative from Plumbago indica has been found to possess various pharmacological properties including anticancer activity. The present study was designed to investigate the inhibitory potential of plumbagin and associated mechanisms in pancreatic cancer cells. Fluorescence and flow cytometric analysis exhibited an increased percentage of apoptotic cells in both monolayer culture and 3D tumor spheroids. Upon plumbagin treatment, reactive oxygen species content of the cancer cells escalated and prompted alleviation of the mitochondrial membrane potential, which triggers caspase-dependent apoptosis. Interestingly, N-acetylcysteine inhibited the plumbagin induced apoptosis. We also found that the expression of Bcl-2 protein decreased and the expression of Bax protein increased. Moreover, plumbagin treatment led to upregulation of cleaved caspase-3 and caspase-9. These results support the views that plumbagin induced stress signals by damaging mitochondria and induce ROS mediated apoptosis via intrinsic apoptotic signaling in pancreatic cancer cells. To summarize, our study suggests that plumbagin may be utilized as a future anti-cancer therapy agent against pancreatic cancer, which is a major threat owing to its stubborn intransigence towards current treatment regimens.

Metal-free semi-aromatic polyester as nanodrug carrier: A novel tumor targeting drug delivery vehicle for potential clinical application.

Polyester nanomaterials have been widely used in drug delivey application from a longer period of time. This study reports the synthesis of metal-free semi-aromatic polyester (SAP) nanomaterial for drug delivery and evaluate its in vivo acute and systemic toxicity for potential clinical application. The ring opening coplymerization of commercially available cyclohexene oxide (CHO) and phthalic anhydride (PA) monomers was carried out to synthesize fully alternating poly(CHO-co-PA) copolymer using metal-free activators. The obtained low Mn SAP was found to be biocompatible, hemocompataible and biodegradable nature. This copolymer was first-time used to fabricate curcumin (CUR) loaded nanoparticles (NPs). These NPs were physicochemically characterized by thermogravimetric analyzer (TGA), X-ray diffraction (XRD), and UV/visible spectrophotometer analysis. Further, these negatively charged core-shell spherical NPs exhibited slow sustained release behavior of CUR with anomalous transport and further displayed its higher intracellular uptake in SiHa cells at different time-periods compared to free CUR. In vitro anti-cancer therapeutic effects of free CUR and poly(CHO-alt-PA)-CUR NPs were evaluated on different cancer cells. We observed the increased cytotoxicity of CUR NPs with low IC50 values compared to free CUR. These results were further substantiated with ex vivo data where, a significant reduction was observed in CUR NPs treated tumor spheroid's size as compared to free CUR. Furthermore, the different doses of metal-free poly(CHO-alt-PA) nanomaterial were tested for its acute and systemic toxicity in BALB/c mice. We did not observe any significant toxicity of tested nanomaterial on vital organs, blood cells and the body weight of mice. Our study suggest that this metal-free SAP nanomaterial can be used for potential clinical application.