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.

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.

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.

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.

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.

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.

Cell signaling and cancer: a mechanistic insight into drug resistance.

Drug resistance is a major setback for advanced therapeutics in multiple cancers. The increasing prevalence of this resistance is a growing concern and bitter headache for the researchers since a decade. Hence, it is essential to revalidate the existing strategies available for cancer treatment and to look after a novel therapeutic approach for target based killing of cancer cells at the genetic level. This review outlines the different mechanisms enabling resistance including drug efflux, drug target alternation, alternative splicing, the release of the extracellular vesicle, tumor heterogeneity, epithelial-mesenchymal transition, tumor microenvironment, the secondary mutation in the receptor, epigenetic alternation, heterodimerization of receptors, amplification of target and amplification of components rather than the target. Furthermore, existing evidence and the role of various signaling pathways like EGFR, Ras, PI3K/Akt, Wnt, Notch, TGF-ß, Integrin-ECM signaling in drug resistance are explained. Lastly, the prevention of this resistance by a contemporary therapeutic strategy, i.e., a combination of specific signaling pathway inhibitors and the cocktail of a cancer drug is summarized showing the new treatment strategies.

The potential of retinoids for combination therapy of lung cancer: Updates and future directions.

Lung cancer is the most common cancer-related death worldwide. Natural compounds have shown high biological and pharmaceutical relevance as anticancer agents. Retinoids are natural derivatives of vitamin A having many regulatory functions in the human body, including vision, cellular proliferation and differentiation, and activation of tumour suppressor genes. Retinoic acid (RA) is a highly active retinoid isoform with promising anti-lung cancer activity. The abnormal expression of retinoid receptors is associated with loss of anticancer activities and acquired resistance to RA in lung cancer. The preclinical promise has not translated to the general clinical utility of retinoids for lung cancer patients, especially those with a history of smoking. Newer retinoid nano-formulations and the combinatorial use of retinoids has been associated with lower toxicity and more favorably efficacy in both the preclinical and clinical settings. Here, we highlight epidemiological and clinical therapeutic studies involving retinoids and lung cancer. We also discuss the biological actions of retinoids in lung cancer, which include effects on cancer stem cell differentiation, angiogenesis, metastasis, and proliferative. We suggest that the use of retinoids in combination with conventional and targeted anticancer agents will broaden the utility of these potent anticancer compounds in the lung cancer clinic.

Emerging role of plumbagin: Cytotoxic potential and pharmaceutical relevance towards cancer therapy.

Plumbagin is a naphthoquinone derived yellow crystalline phytochemical. Plumbagin has a wide range of biological effects including cytotoxicity against cancer cells both in vitro and in vivo. Due to the pleiotropic nature of plumbagin, it shows the anticancer effect by targeting several molecular mechanisms including apoptosis and autophagic pathways, cell cycle arrest, anti-angiogenic pathways, anti-invasion and anti-metastasis pathways. Among many signaling pathways the key regulatory genes regulated by plumbagin are NF-kß, STAT3, and AKT, etc. Plumbagin is also a potent inducer of ROS, suppressor of cellular glutathione, and causes DNA strand break by oxidative DNA base damages. In vivo studies suggested that plumbagin significantly reduces the tumor weight and volume in dose-dependent manner without any side effects in tested model organisms. Another exciting aspect of plumbagin is the ability to re-sensitize the chemo and radioresistant cancer cells when used in combination or alone. Nano encapsulation of plumbagin overcomes the poor water solubility and bioavailability obstacles, enhancing the pharmaceutical relevance with better therapeutic efficacy. Moreover, plumbagin can be introduced as a future phytotherapeutic anticancer drug after fully satisfied preclinical and clinical trials.

Pterospermum acerifolium (L.) wild bark extract induces anticarcinogenic effect in human cancer cells through mitochondrial-mediated ROS generation.

Plants have many medicinal properties including anticancer activity due to the presence of several secondary metabolites. Current cancer treatment policies are not much effective because of side effects and resistance development. Therefore, the discovery of new phytotherapeutics with no or fewer side effects is highly needed. Pterospermum acerifolium (L.) wild, an angiosperm has a broad application in traditional Indian medicinal system including cancer treatment. Despite, there is no study available on the cytotoxic and apoptotic effect of P. acerifolium in human cancer cells. Exploring the medicinal properties of P. acerifolium plant by its traditional use will be helpful towards developing novel cancer therapeutics. Hence, we decided to demonstrate the anti-carcinogenic property of P. acerifolium ethanolic bark extract against lung (A549) and pancreatic (PANC-1) cancer cells. The cytotoxicity was demonstrated by MTT assay, morphological changes, and scratch invasion assay. Flow cytometry, fluorescence staining techniques, and cell cycle analysis were confirmed the apoptotic property of P. acerifolium plant. The cell viability assay revealed that P. acerifolium ethanolic bark extract significantly reduced the viability of both A549 and PANC-1 cells. Moreover, PANC-1 cells showed more sensitivity towards P. acerifolium ethanolic bark extract than A549 at higher concentrations. Clear visualization of changes such as cytoplasmic condensation, cellular morphology, cell shrinkage, and augmented number of dead cells in both the cancer cells was observed after treatment. Scratch and invasion assay showed that cell migration and invasion rate of both the cancer cells were significantly reduced. Fluorescence microscopic studies using acridine orange/ethidium bromide and DAPI (4', 6-diamidino-2-phenylindole) staining showed early and late apoptotic symptoms after treatment with bark extract. Rhodamine-123 and DCFH-DA staining analysis by fluorescence and flow cytometry showed that bark extract depolarized the mitochondria membrane potential and induced reactive oxygen species (ROS) generation. Cell cycle analysis through flow cytometry using propidium iodide stain showed that P. acerifolium bark extract arrested A549 and PANC-1 cells in sub-G1 phase stated early apoptosis. These findings collectively point to the fact that P. acerifolium bark extract induced cell cytotoxicity in lung and pancreatic cancer cells by modulating mitochondrial-mediated ROS generation, and cell cycle checkpoints.

Augmented sensitivity to methotrexate by curcumin induced overexpression of folate receptor in KG-1 cells.

Folate receptors are targets of various strategies aimed at efficient delivery of anti-cancer drugs. Folate receptors also play a role in the uptake of antifolate drugs which are used for therapeutic intervention in leukemia. Therefore, it is important to identify compounds which regulate expression of folate receptors in leukemic cells. The present study examined if curcumin could modulate the uptake and cytotoxicity of the antifolate drug methotrexate, in KG-1 leukemic cells. This is the first report to show that curcumin (10-50 µM) causes a significant, dose-dependent, 2-3 fold increase in uptake of radiolabelled folic acid and methotrexate into KG-1 cells both at 24 h and 48 h of treatment. Interestingly, pre-treatment of KG-1 leukemic cells with curcumin (10 µM and 25 µM) also caused a statistically significant enhancement in the cytotoxicity of methotrexate. We performed Real Time Quantitative RT-PCR to confirm the upregulation of FRß mRNA in curcumin treated cells. Immunocytochemistry and Western blotting showed that curcumin caused increased expression of folate receptor ßin KG-1 cells. Our data show that the mechanism of curcumin action involves up-regulation of folate receptor ß mRNA and protein in KG-1 cells. Therefore, combination of non-toxic concentrations of curcumin and methotrexate, may be a viable strategy for therapeutic intervention for leukemias using a folate receptor-targeted drug delivery system.

Acute hypersensitivity of pluripotent testicular cancer-derived embryonal carcinoma to low-dose 5-aza deoxycytidine is associated with global DNA Damage-associated p53 activation, anti-pluripotency and DNA demethylation.

Human embryonal carcinoma (EC) cells are the stem cells of nonseminoma testicular germ cells tumors (TGCTs) and share remarkable similarities to human embryonic stem (ES) cells. In prior work we found that EC cells are hypersensitive to low nanomolar doses of 5-aza deoxycytidine (5-aza) and that this hypersensitivity partially depended on unusually high levels of the DNA methyltransferase, DNMT3B. We show here that low-dose 5-aza treatment results in DNA damage and induction of p53 in NT2/D1 cells. In addition, low-dose 5-aza results in global and gene specific promoter DNA hypomethylation. Low-dose 5-aza induces a p53 transcriptional signature distinct from that induced with cisplatin in NT2/D1 cells and also uniquely downregulates genes associated with pluripotency including NANOG, SOX2, GDF3 and Myc target genes. Changes in the p53 and pluripotency signatures with 5-aza were to a large extent dependent on high levels of DNMT3B. In contrast to the majority of p53 target genes upregulated by 5-aza that did not show DNA hypomethylation, several other genes induced with 5-aza had corresponding decreases in promoter methylation. These genes include RIN1, SOX15, GPER, and TLR4 and are novel candidate tumors suppressors in TGCTs. Our studies suggest that the hypersensitivity of NT2/D1 cells to low-dose 5-aza is multifactorial and involves the combined activation of p53 targets, repression of pluripotency genes, and activation of genes repressed by DNA methylation. Low-dose 5-aza therapy may be a general strategy to treat those tumors that are sustained by cells with embryonic stem-like properties.GEO NUMBER FOR THE MICROARRAY DATA: GSE42647.

Development of a targeted siRNA delivery system using FOL-PEG-PEI conjugate.

Receptor mediated delivery of siRNA enables silencing of target genes in specific tissues. Folate receptor (FR) is an attractive target for tumor-selective gene delivery. The focus of this study was to deliver the dihydrofolate reductase (DHFR) siRNA expressing plasmid and to silence the DHFR gene in FR positive KB cells, by complexing the plasmid with a folate-polyethylene glycol-polyethylenimine (FOL-PEG-PEI) conjugate, as a gene carrier. A DHFR siRNA sequence was cloned into a pSUPER-RNAi vector and complexed with the FOL-PEG-PEI conjugate. The complex was characterized by particle size analyzer, gel retardation and DNase protection assay. The FOL-PEG-PEI/pSUPER-siDHFR complex was transfected to FR overexpressing (KB) and FR negative (A549) cells. The transfection effiencies and gene inhibition were analyzed by fluorescence microscopy and RT-PCR. The pSUPER-siDHFR/PEI-PEG-FOL complex delivered the siRNA vector and inhibited DHFR gene in KB cells, while A549 cells were unaffected. Lipofectamine mediated transfection of pSUPER-siDHFR, delivered the vector and inhibited the DHFR gene in both KB and A549 cells. FR mediated delivery of siDHFR complexed with PEI-PEG-FOL conjugate inhibits the DHFR expression in FR positive cells alone. This strategy can be extended to deliver a wide range of drugs and post-transcriptional gene silencing therapeutics.

Tumor cell imaging using the intrinsic emission from PAMAM dendrimer: a case study with HeLa cells.

HeLa 229 cells were treated with methotrexate (MTX) and doxorubicin (DOX), utilizing fourth generation (G4), amine terminated poly(amidoamine) {PAMAM} dendrimer as the drug carrier. In vitro kinetic studies of the release of both MTX and DOX in presence and absence of G4, amine terminated PAMAM dendrimers suggest that controlled drug release can be achieved in presence of the dendrimers. The cytotoxicity studies indicated improved cell death by dendrimer-drug combination, compared to the control experiments with dendrimer or drug alone at identical experimental conditions. Furthermore, HeLa 229 cells were imaged for the first time utilizing the intrinsic emission from the PAMAM dendrimers and drugs, without incorporating any conventional fluorophores. Experimental results collectively suggest that the decreased rate of drug efflux in presence of relatively large sized PAMAM dendrimers generates high local concentration of the dendrimer-drug combination inside the cell, which renders an easy way to image cell lines utilizing the intrinsic emission properties of PAMAM dendrimer and encapsulated drug molecule.