NSD2 is a requisite subunit of the AR/FOXA1 neo-enhanceosome in promoting prostate tumorigenesis

The androgen receptor (AR) is a ligand-responsive transcription factor that binds at enhancers to drive terminal differentiation of the prostatic luminal epithelia. By contrast, in tumors originating from these cells, AR chromatin occupancy is extensively reprogrammed to drive hyper-proliferative, metastatic, or therapy-resistant phenotypes, the molecular mechanisms of which remain poorly understood. Here, we show that the tumor-specific enhancer circuitry of AR is critically reliant on the activity of Nuclear Receptor Binding SET Domain Protein 2 (NSD2), a histone 3 lysine 36 di-methyltransferase. NSD2 expression is abnormally gained in prostate cancer cells and its functional inhibition impairs AR trans-activation potential through partial off-loading from over 40,000 genomic sites, which is greater than 65% of the AR tumor cistrome. The NSD2-dependent AR sites distinctly harbor a chimeric AR-half motif juxtaposed to a FOXA1 element. Similar chimeric motifs of AR are absent at the NSD2-independent AR enhancers and instead contain the canonical palindromic motifs. Meta-analyses of AR cistromes from patient tumors uncovered chimeric AR motifs to exclusively participate in tumor-specific enhancer circuitries, with a minimal role in the physiological activity of AR. Accordingly, NSD2 inactivation attenuated hallmark cancer phenotypes that were fully reinstated upon exogenous NSD2 re-expression. Inactivation of NSD2 also engendered increased dependency on its paralog NSD1, which independently maintained AR and MYC hyper-transcriptional programs in cancer cells. Concordantly, a dual NSD1/2 PROTAC degrader, called LLC0150, was preferentially cytotoxic in AR-dependent prostate cancer as well as NSD2-altered hematologic malignancies. Altogether, we identify NSD2 as a novel subunit of the AR neo-enhanceosome that wires prostate cancer gene expression programs, positioning NSD1/2 as viable paralog co-targets in advanced prostate cancer.

Loss of LCMT1 and biased protein phosphatase 2A heterotrimerization drive prostate cancer progression and therapy resistance

Loss of the tumor suppressive activity of the protein phosphatase 2A (PP2A) is associated with cancer, but the underlying molecular mechanisms are unclear. PP2A holoenzyme comprises a heterodimeric core, a scaffolding A subunit and a catalytic C subunit, and one of over 20 distinct substrate-directing regulatory B subunits. Methylation of the C subunit regulates PP2A heterotrimerization, affecting B subunit binding and substrate specificity. Here, we report that the leucine carboxy methyltransferase (LCMT1), which methylates the L309 residue of the C subunit, acts as a suppressor of androgen receptor (AR) addicted prostate cancer (PCa). Decreased methyl-PP2A-C levels in prostate tumors is associated with biochemical recurrence and metastasis. Silencing LCMT1 increases AR activity and promotes castration-resistant prostate cancer growth. LCMT1-dependent methyl-sensitive AB56αCme heterotrimers target AR and its critical coactivator MED1 for dephosphorylation, resulting in the eviction of the AR-MED1 complex from chromatin and loss of target gene expression. Mechanistically, LCMT1 is regulated by S6K1-mediated phosphorylation-induced degradation requiring the β-TRCP, leading to acquired resistance to anti-androgens. Finally, feedforward stabilization of LCMT1 by small molecule activator of phosphatase (SMAP) results in attenuation of AR-signaling and tumor growth inhibition in anti-androgen refractory PCa. These findings highlight methyl-PP2A-C as a prognostic marker and that the loss of LCMT1 is a major determinant in AR-addicted PCa, suggesting therapeutic potential for AR degraders or PP2A modulators in prostate cancer treatment.

Capra cartilage-derived peptide delivery via carbon nano-dots for cartilage regeneration

Targeted delivery of site-specific therapeutic agents is an effective strategy for osteoarthritis treatment. The lack of blood vessels in cartilage makes it difficult to deliver therapeutic agents like peptides to the defect area. Therefore, nucleus-targeting zwitterionic carbon nano-dots (CDs) have immense potential as a delivery vehicle for effective peptide delivery to the cytoplasm as well as nucleus. In the present study, nucleus-targeting zwitterionic CDs have been synthesized as delivery vehicle for peptides while also working as nano-agents towards optical monitoring of cartilage healing. The functional groups of zwitterion CDs were introduced by a single-step microwave assisted oxidation procedure followed by COL II peptide conjugation derived from Capra auricular cartilage through NHS/EDC coupling. The peptide-conjugated CDs (PCDs) allows cytoplasmic uptake within a short period of time (∼30 m) followed by translocation to nucleus after ∼24 h. Moreover, multicolor fluorescence of PCDs improves (blue, green, and read channel) its sensitivity as an optical code providing a compelling solution towards enhanced non-invasive tracking system with multifunctional properties. The PCDs-based delivery system developed in this study has exhibited superior ability to induce ex-vivo chondrogenic differentiation of ADMSCs as compared to bare CDs. For assessment of cartilage regeneration potential, pluronic F-127 based PCDs hydrogel was injected to rabbit auricular cartilage defects and potential healing was observed after 60 days. Therefore, the results confirm that PCDs could be an ideal alternate for multimodal therapeutic agents.

Magnolol induces cytotoxic autophagy in glioma by inhibiting PI3K/AKT/mTOR signaling

Glioma is difficult-to-treat because of its infiltrative nature and the presence of the blood-brain barrier. Temozolomide is the only FDA-approved drug for its management. Therefore, finding a novel chemotherapeutic agent for glioma is of utmost importance. Magnolol, a neolignan, has been known for its apoptotic role in glioma. In this work, we have explored a novel anti-glioma mechanism of Magnolol associated with its role in autophagy modulation. We found increased expression levels of Beclin-1, Atg5-Atg12, and LC3-II and lower p62 expression in Magnolol-treated glioma cells. PI3K/AKT/mTOR pathway proteins were also downregulated in Magnolol-treated glioma cells. Next, we treated the glioma cells with Insulin, a stimulator of PI3K/AKT/mTOR signaling, to confirm that Magnolol induced autophagy by inhibiting this pathway. Insulin reversed the effect on Magnolol-mediated autophagy induction. We also established the same in in vivo glioma model where Magnolol showed an anti-glioma effect by inducing autophagy. To confirm the cytotoxic effect of Magnolol-induced autophagy, we used Chloroquine, a late-stage autophagy inhibitor. Chloroquine efficiently reversed the anti-glioma effects of Magnolol both in vitro and in vivo. Our study revealed the cytotoxic effect of Magnolol-induced autophagy in glioma, which was not previously reported. Additionally, Magnolol showed no toxicity in non-cancerous cell lines as well as rat organs. Thus, we concluded that Magnolol is an excellent candidate for developing new therapeutic strategies for glioma management.

Oncofusion-driven de novo enhancer assembly promotes malignancy in Ewing sarcoma via aberrant expression of the stereociliary protein LOXHD1

Ewing sarcoma (EwS) is a highly aggressive tumor of bone and soft tissues that mostly affects children and adolescents. The pathognomonic oncofusion EWSR1::FLI1 transcription factor drives EwS by orchestrating an oncogenic transcription program through de novo enhancers. By integrative analysis of thousands of transcriptomes representing pan-cancer cell lines, primary cancers, metastasis, and normal tissues, we identify a 32-gene signature (ESS32 [Ewing Sarcoma Specific 32]) that stratifies EwS from pan-cancer. Among the ESS32, LOXHD1, encoding a stereociliary protein, is the most highly expressed gene through an alternative transcription start site. Deletion or silencing of EWSR1::FLI1 bound upstream de novo enhancer results in loss of the LOXHD1 short isoform, altering EWSR1::FLI1 and HIF1α pathway genes and resulting in decreased proliferation/invasion of EwS cells. These observations implicate LOXHD1 as a biomarker and a determinant of EwS metastasis and suggest new avenues for developing LOXHD1-targeted drugs or cellular therapies for this deadly disease.

TGF-β1 induced autophagy in cancer associated fibroblasts during hypoxia contributes EMT and glycolysis via MCT4 upregulation

The Transforming growth factor-β1(TGF- β1) in the tumor microenvironment(TME) is the major cytokine that acts as a mediator of tumor-stroma crosstalk, which in fact has a dual role in either promoting or suppressing tumor development. The cancer-associated fibroblasts (CAFs) are the major cell types in the TME, and the interaction with most of the epithelial cancers is the prime reason for cancer survival. However, the molecular mechanisms, associated with the TGF- β1 induced tumor promotion through tumor-CAF crosstalk are not well understood. In the Reverse Warburg effect, CAFs feed the adjacent cancer cells by lactate produced during the aerobic glycolysis. We hypothesized that the monocarboxylate transporter, MCT4 which is implicated in lactate efflux from the CAFs, must be overexpressed in the CAFs. Contextually, to explore the role of TGF- β1 in the hypoxia-induced autophagy in CAFs, we treated CoCl₂ and external TGF- β1 to the human dermal fibroblasts and L929 murine fibroblasts. We demonstrated that hypoxia accelerated the TGF- β1 signaling and subsequent transformation of normal fibroblasts to CAFs. Moreover, we elucidated that synergistic induction of autophagy by hypoxia and TGF- β1 upregulate the aerobic glycolysis and MCT4 expression in CAFs. Furthermore, we showed a positive correlation between glucose consumption and MCT4 expression in the CAFs. Autophagy was also found to be involved in the EMT in hypoxic CAFs. Collectively, these findings reveal the unappreciated role of autophagy in TME, which enhances the CAF transformation and that promotes tumor migration and metastasis via the reverse Warburg effect.

Screening of the Prime bioactive compounds from Aloe vera as potential anti-proliferative agents targeting DNA

BACKGROUND

Aloe vera extract and its bioactive compounds possess anti-proliferative properties against cancer cells. However, no detailed molecular mechanism of action studies has been reported. We have now employed a computational approach to scrutinize the molecular mechanism of lead bioactive compounds from Aloe vera that potentially inhibit DNA synthesis.

METHODS

Initially, the anti-proliferative activity of Aloe vera extract was examined in human breast cancer cells (in vitro/in vivo). Later on, computational screening of bioactive compounds from Aloe vera targeting DNA was performed by molecular docking and molecular dynamics simulation.

RESULTS

In-vitro and in-vivo studies confirm that Aloe vera extract effectively suppresses the growth of breast cancer cells without significant cytotoxicity towards non-cancerous normal immortal cells. Computational screening predicts that growth suppression may be due to the presence of DNA intercalating bioactive compounds (riboflavin, daidzin, aloin, etc.) contained in Aloe vera. MM/PBSA calculation showed that riboflavin has a higher binding affinity at the DNA binding sites compared to standard drug daunorubicin.

CONCLUSIONS

These observations support the hypothesis that riboflavin may be exploited as an anti-proliferative DNA intercalating agent to prevent cancer and is worthy of testing for the management of cancer by performing more extensive pre-clinical and if validated clinical trials.

Natural products based nanoformulations for cancer treatment: Current evolution in Indian research

The use of medicinal plants is as ancient as human civilization. The development of phytochemistry and pharmacology facilitates the identification of natural bioactive compounds and their mechanisms of action, including against cancer. The efficacy and the safety of a bioactive compound depend on its optimal delivery to the target site. Most natural bioactive compounds (phenols, flavonoids, tannins, etc.) are unable to reach their target sites due to their low water solubility, less cellular absorption, and high molecular weight, leading to their failure into clinical translation. Therefore, many scientific studies are going on to overcome the drawbacks of natural products for clinical applications. Several studies in India, as well as worldwide, have proposed the development of natural products-based nanoformulations to increase their efficacy and safety profile for cancer therapy by improving the delivery of natural bioactive compounds to their target site. Therefore, we are trying to discuss the development of natural products-based nanoformulations in India to improve the efficacy and safety of natural bioactive compounds against cancer.

Paracrine TGF-β1 from breast cancer contributes to chemoresistance in cancer associated fibroblasts via upregulation of the p44/42 MAPK signaling pathway

Conventionally, Cancer-associated fibroblasts (CAFs) are considered as an inducer of chemoresistance in cancer cells. However, the underlying mechanism by which carcinomas induce chemoresistance in CAFs through tumor-stroma cross-talk is largely unknown. Henceforth, we uncovered a network of paracrine signals between carcinoma and CAFs that drives chemoresistance in CAFs. Acquired tamoxifen and 5-Fu resistant cell lines MCF-7 and MDA-MB-468 respectively showed higher apoptotic resistance compared to the parental cell. Besides, chemoresistant breast cancer cells showed overexpression of TGF-β1 and have the higher potential to induce CAF phenotype in the normal dermal fibroblasts in a paracrine manner through the TGF-β1 cytokine, compared to their parental cell. Moreover, the chemoresistant cancer cells augmented the EMT markers with a reduction of E-cadherin in the CAFs. Importantly we found out that the TGF- β1 enriched conditioned media from both of the resistant cells triggered chemoresistance in the CAFs by p44/42 MAPK signaling axis. Mechanistically, pharmacological and genetic blockade of TGF-β1 inhibits p44/42 MAPK activation with the subsequent restoration of chemosensitivity in the CAFs. Altogether we ascertained that chemoresistant cancer cells have tremendous potential to modulate the CAFs compared to the parental counterpart. Targeting TGF-β1 and p44/42 MAPK signaling in the future may help to abrogate the chemoresistance in the CAFs.

Cancer associated fibroblast mediated chemoresistance: A paradigm shift in understanding the mechanism of tumor progression

One of the undeniable issues with cancer eradication is the evolution of chemoresistance in due course of treatment, and the mechanisms of chemoresistance have been the subject of extensive research for several years. The efficacy of chemotherapy is hindered by cancer epithelium, mostly in a cell-autonomous mechanism. However, recently the valid experimental evidence showed that the surrounding tumor microenvironment (TME) is equivalently responsible for the induction of chemoresistance. Of the verities of cells in the tumor microenvironment, cancer-associated fibroblasts (CAFs) are the major cellular component of TME and act as a key regulator in the acquisition of cancer chemoresistance by providing a protective niche to the cancer cells against the anti-cancer drugs. Moreover, the symbiotic relationship between the tumor and CAFs to obtain key resources such as growth factors and nutrients for optimal tumor growth and proliferation favors the chemoresistance phenotype. Here, in this review, we provide an up-to-date overview of our knowledge of the role of the CAFs in inducing chemoresistance and tumor progression. We also further delineated the emerging events leading to the CAF origins and activation of normal fibroblasts to CAFs. Along with this, we also discuss the novel area of research confined to the CAF targeted therapies of cancer. The identification of CAF-specific markers may allow unveiling new targets and avenues for blunting or reverting the detrimental pro-tumorigenic potential of CAFs in the foreseeable future.

Pro-survival autophagy: An emerging candidate of tumor progression through maintaining hallmarks of cancer

Autophagy is an evolutionary conserved catabolic process that regulates the cellular homeostasis by targeting damaged cellular contents and organelles for lysosomal degradation and sustains genomic integrity, cellular metabolism, and cell survival during diverse stress and adverse conditions. Recently, the role of autophagy is extremely debated in the regulation of cancer initiation and progression. Although autophagy has a dichotomous role in the regulation of cancer, growing numbers of studies largely indicate the pro-survival role of autophagy in cancer progression and metastasis. In this review, we discuss the detailed mechanisms of autophagy, the role of pro-survival autophagy that positively drives several classical as well as emerging hallmarks of cancer for tumorigenic progression, and also we address various autophagy inhibitors that could be harnessed against pro-survival autophagy for effective cancer therapeutics. Finally, we highlight some outstanding problems that need to be deciphered extensively in the future to unravel the role of autophagy in tumor progression.

Abstract 120: Paracrine TGF-β1 induces tamoxifen resistance in cancer-associated fibroblsts by activation of p44/42 MAPK signaling pathway

Introduction: Biochemical crosstalk between tumor and stroma by several secretory factors has evolved as a significant contributor for the development of therapeutic resistance in breast cancer, where cancer-associated fibroblasts (CAFs) in the tumor stroma play a critical role. However, the role of secretory factors of cancer cells in assisting CAF chemoresistance is least apparent. TGF-β is the major cytokine secreted by the cancer cells to the tumor stroma that further imparts resistance in CAFs to the chemotherapy. Here, we hypothesize that tamoxifen-resistant breast cancer cells stimulate surrounding CAFs towards chemoresistant phenotype through TGF-β1 activated p44/42 MAPK signaling pathway.

Methodology: The tamoxifen-resistant (TAM-R) clones of parental MCF-7 cell line were established by treating with sub-lethal doses over several cycles and characterized by MTT assay. Western blot (WB) was performed to quantify the TGF-β1 expression in the parental MCF-7 and the resistant MCF-7 (MCF-7/TAM-R) cells. ELISA was carried out to quantify TGF-β1 in the conditioned media (CM) from MCF-7 and MCF-7/TAM-R. CM from both the MCF-7 and MCF-7/TAM-R was collected and treated to the fibroblasts in dose and time-dependent manner. Initial screening for the expression of CAF markers α-SMA and caveolin-1 was carried out by qPCR and confirmed by WB. Cell cycle analysis was performed by flow cytometry and WB. Scratch assay was performed to evaluate migration and proliferation activity of CAFs. Downstream signaling pathway analysis was carried out by WB. Expression of TGF-β1 and p44/42 was downregulated by appropriate inhibitors.

Results: Tamoxifen treatment to the MCF-7 cells showed a marked increase in TGF- β1 expression both in time and dose-dependent manner. α-SMA was upregulated, and Caveolin-1 was downregulated in CAFs after treatment of CM from MCF-7/ TAM-R cells. MTT result showed a higher IC50 value of TAM in CAFs treated with CM compared to untreated one. WB analysis confirmed the elevated anti-apoptotic and reduced pro-apoptotic protein expressions in CAFs post-treatment. Flow cytometry analysis depicts less number of cells in the sub G0/G1 phage after TAM treatment in CM treated CAFs compared to untreated one. WB results showed increased cyclin D1, and cyclin E in CM treated CAFs. Further, inhibiting TGF- β1 in MCF-7/TAM-R cells and p44/42 MAPK signaling cascade in CM treated CAFs found a strong correlation between the elevated expressions of TGF- β1 in MCF-7/TAM-R cells and p44/42 signaling pathway in CM treated CAFs.

Conclusion: Here we report that chemoresistant breast cancer cells with increased TGF- β1 expression exhibit a greater potential in inducing TAM resistance in CAFs compared to parental cells, with an up-regulated p44/42 MAPK signaling cascade. The mechanism underscores the p44/42 MAPK signaling pathway as an important therapeutic target in tumor stroma.

Note: This abstract was not presented at the meeting.

Citation Format: Bikash Chandra Jena, Chandan Kanta Das, Deblina Bharadwaj, Subhayan Das, Indranil Banerjee, Santosh Gupta, Mahitosh Mandal. Paracrine TGF-β1 induces tamoxifen resistance in cancer-associated fibroblsts by activation of p44/42 MAPK signaling pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 120.

Abstract 3638: Combination of metformin and metronomic liposomal doxorubicin exerts a robust anticancer effect in triple negative breast cancer by inhibiting breast cancer stem cells & the Wnt/beta-catenin pathway

Introduction: The high death rate due to breast cancer is often attributed to aggressive triple negative breast cancer (TNBC). We used the combination of metronomic pegylated liposomal doxorubicin (PLD), and metformin {selectively inhibits cancer stem cells (CSCs)} for effective management of TNBC xenografts generated in mice. Down-regulation of β-catenin is responsible for the efficacy of the combination of metronomic PLD and metformin in treating aggressive TNBC.

Methodology: PLD was prepared using the ammonium sulfate gradient method. Morphology, particle size, zeta potential measurement, drug entrapment efficiency, and drug release studies were performed to characterize the prepared liposomal formulation. Cell culture studies were performed on MDA-MB-231 and MDA-MB-468 cell lines (i.e., TNBC cells). MTT assays, mammosphere assays, apoptosis assays, quantitative real-time polymerase chain reactions (qPCR), western blotting experiments were performed. In vivo anticancer efficacy of the combination therapy {antidiabetic dosing of metformin: 150 mg/kg body weight every day, and metronomic dosing of PLD: 1 mg/kg body weight with respect to doxorubicin (Dox) every other day for 3 weeks} was verified in an MDA-MB-231 xenograft model.

Results: Monodisperse PLD having dimensions less than 100 nm was successfully prepared (confirmed by AFM, TEM, and DLS). Zeta potential measurement showed that PLD was negatively charged (- 12.1 ± 2.3 mV, n = 3). Encapsulation efficiency and drug release were found to be satisfactory. IC50 (i.e., 50 % inhibitory concentration) of PLD was found to be in nanomolar range with respect to Dox in TNBC cell lines. However, a combination of metformin (500 µM) and PLD resulted in a leftward shift of the concentration-response curve such that the IC50 value of PLD was further reduced in the nanomolar range with respect to Dox. A similar trend was seen in the apoptosis assay. Metformin works together with PLD to reduce non-stem cancer cells, CSCs, and stem cell markers as indicated by the reduction in the number of mammospheres, qPCR results, and western blotting experiments. We also found attenuation of β-catenin in TNBC cells by the combination treatment regimen, as suggested by qPCR and western blotting. Some of the in vitro observations were also confirmed in the MDA-MB-231 xenograft model.

Conclusion: Our experiments demonstrate that down-regulation of β-catenin is responsible for the strong anticancer effects of the combination of metformin and PLD in vitro and in vivo. Further studies are warranted with this combination regimen in different cancer types as metformin is an approved anti-diabetic drug with an acceptable safety profile, and metronomic chemotherapy is gaining popularity in treating different cancer types.

Citation Format: Indranil Banerjee, Subhayan Das, Chandan Kanta Das, Bikash Ch. Jena, Deblina Bharadwaj, Anjan K. Pradhan, Swadesh K. Das, Paul B. Fisher, Mahitosh Mandal. Combination of metformin and metronomic liposomal doxorubicin exerts a robust anticancer effect in triple negative breast cancer by inhibiting breast cancer stem cells & the Wnt/beta-catenin pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3638.

Lactate dehydrogenase A regulates autophagy and tamoxifen resistance in breast cancer

Estrogen receptor (ER) antagonist, tamoxifen has been universally used for the treatment of the ER-positive breast cancer; however, the inevitable emergence of resistance to tamoxifen obstructs the successful treatment of this cancer. So, there is an immediate requirement for the search of a novel therapeutic target for treatment of this cancer. Acquired tamoxifen-resistant breast cancer cell lines MCF-7 (MCF-7/TAM-R) and T47D (T47D/TAM-R) showed higher apoptotic resistance accompanied by induction of pro-survival autophagy compared to their parental cells. Besides, tamoxifen resistance was associated with reduced production of ATP and with overexpression of glycolytic pathways, leading to induced autophagy to meet the energy demand. Further, our study revealed that LDHA; one of the key molecules of glycolysis in association with Beclin-1 induced pro-survival autophagy in tamoxifen-resistant breast cancer. Mechanistically, pharmacological and genetic inhibition of LDHA reduced the pro-survival autophagy, with the restoration of apoptosis and reverting back the EMT like phenomena noticed in tamoxifen-resistant breast cancer. In total, targeting LDHA opened a novel strategy to interrupt autophagy and tamoxifen resistance in breast cancer.

Exosome as a Novel Shuttle for Delivery of Therapeutics across Biological Barriers

The effective delivery of target-specific siRNA to the brain by exploiting the exosomes derived from dendritic cells renders the paradigm shift for the prospective use of nanosized exosomes as a delivery system. Although the in vivo targeting strategies by other nanovesicles like liposomes exist, still this novel exosome-based delivery approach holds an inclusive dominance of in vivo security and reduced immunogenicity. Achieving promising exosome-based delivery strategies warrants more desirable exploration of their biology. Over the years, the invention of novel production, characterization, targeting strategies, and cargo loading techniques of exosome improved its ability to reach clinics. Essentially, exosome-based delivery of therapeutics assures to conquer the major hurdles, like delivery of cargos across impermeable biological barriers, like the blood-brain barrier, biocompatibility, increased solubility, metabolic stability, improved circulation time, target specific delivery, and pharmacokinetics, and thereby enhanced the efficacy of loaded therapeutic agents. In this article, we cover the current status of exosome as a delivery vehicle for therapeutics and the challenges that need to be overcome, and we also discuss future perspectives of this exciting field of research to transform it from bench to clinical reality.

Prevalence of Generalized Anxiety Disorder and its effect on Daily Living in the Rural Community of Rajshahi

This cross-sectional type of descriptive study was conducted in three villages of Puthia Upazila under Rajshahi district to find out the prevalence of Generalized Anxiety Disorder (GAD) and its effect on their daily living. A total of 876 adult people of aged 18 years and above, were selected purposively. Data were collected by face to face interview with the help of a semi-structured questionnaire which contained Hamilton’s 7-point anxiety scale. Out of 876 respondents, 80% had GAD, where mild, moderate and severe GAD being 42.5%, 31.8% and 5.7% respectively. GAD was found to be more frequently associated in the 3rd and 5th decades of life, which constituted 27% and 12.9% respectively (p < 0.001). Having GAD, females have more ability to cope with daily living than males, though GAD was not found to be associated with sex (p >0.05). Illiterate and primary level educated respondents were more often associated with GAD (40.4 and 25% respectively) than the SSC and higher level educated people (p < 0.001). Businessmen were found to be significantly associated with GAD (29.7%) than the other occupations (p < 0.001). Poor people tend to be associated with GAD significantly more than the middle class and the rich (p < 0.01). Widow(er) and married and living together were likely to have GAD than the single or divorced or separated (p < 0.001). Activities of daily living gradually becoming more difficult when intensity of anxiety status increased which is statistically significant (p<0.001).The association between sex and problem facing in everyday life shows that over 40% of the females did not have any difficulty in dealing with problem situation as compared to only 25.8% of the males, while nearly half (48.6%) of males had quite difficulty in dealing with a problem as compared to 37.3% in females (p < 0.001). The present study concluded that majority rural adult people (4 in every five) suffer from generalized anxiety disorder (GAD). The ability of coping with a problem is higher in females than the males. This study might be the basis for further in depth study in this regard.TAJ 2014; 27(1): 14-23

Abstract 1348: Parkin-mediated mitophagy regulates 5-fluorouracil-induced chemoresistance in breast cancer

Introduction Resistance to therapeutics is one of the major concerns for treatment failure in breast cancer. The use of antimetabolite, 5 Fluorouracil (5-FU) based combinational therapies have been an ideal treatment blueprint for different types of solid tumors including breast cancer. However, the efficacy of 5-FU based treatment is limited due to development of resistance. Recently mitophagy has evolved as an important cell survival mechanisms in response to different stress stimuli associated with cancer treatments. Mitophagy is the selective form of autophagy that removes damaged mitochondria. Although mitophagy has dual role in context to cell survival and cell death, still a large number of evidences suggests their prosurvival role with respect to chemoresistance. Here we investigated the role of mitophagy in 5-FU induced breast cancer chemoresistance.

Methodology Chemoresistant cell lines were established by continuous exposure to increasing concentration of 5-FU to breast cancer cell lines (MDA-MB-231 and MDA-MB-468). Chemoresistant cells were characterized by MTT assay, caspase assay and western blot. Induction of autophagy was confirmed by GFP LC3 transfection and western blot. Further prosurvival autophagy was asserted through FACS by using autophagy inhibitor chloroquine (CQ) and stable ATG5 lentiviral knockdown. Mitophagy was confirmed using MTDR (detects mitochondrial mass) and TMRM (detects mitochondrial membrane potential) through FACS. Further immunofluorescence and western blot were used to confirm key mitophagy markers (TOM20 and Porin) with CQ treatments. Involvement of parkin mediated mitophagy was later confirmed by cytosolic/mitochondrial fractionation assay and by siRNA knockdown.

Results Characterization study reveals chemoresistant cells were more apoptosis resistant compared to their parental counterparts.The levels of the autophagy markers LC3-II, p62, ATG5 and Beclin-1 were elevated in chemoresistant cells while mitochondrial mass and mitochondrial membrane potential were reduced. Treatment of CQ and ATG5 knockdown significantly augment 5-FU sensitivity in chemoresistant cells. Simultaneously CQ treatment increased TOM20 and porin expression revealing induction of mitophagy in chemoresistant cells. Further cell fractionation assay and siRNA knockdown of Parkin confirm its mitochondrial localization and prosurvival function in 5-FU resistant breast cancer respectively. some important in vitro findings were also confirmed in xenograft breast cancer model.

Conclusion Here we noticed that chemoresistant breast cancer cells exhibit greater apoptosis resistance to 5-FU compared to parental cells along with enhanced cytoprotective mitophagy, also underscoring the involvement of parkin mediated induction of mitophagy in chemoresistant breast cancer.

Citation Format: Chandan Kanta Das, Bikash Chandra Jena, Subhayan Das, Aditya Parekh, Goutam Dey, Rashmi Bharti, Deblina Bharadwaj, Sujit Kumar Bhutia, Donat Kögel, Mahitosh Mandal. Parkin-mediated mitophagy regulates 5-fluorouracil-induced chemoresistance in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1348.

Multi-nucleated cells use ROS to induce breast cancer chemo-resistance in vitro and in vivo

Although there is a strong correlation between multinucleated cells (MNCs) and cancer chemo-resistance in variety of cancers, our understanding of how multinucleated cells modulate the tumor micro-environment is limited. We captured multinucleated cells from triple-negative chemo-resistant breast cancers cells in a time frame, where they do not proliferate but rather significantly regulate their micro-environment. We show that oxidatively stressed MNCs induce chemo-resistance in vitro and in vivo by secreting VEGF and MIF. These factors act through the RAS/MAPK pathway to induce chemo-resistance by upregulating anti-apoptotic proteins. In MNCs, elevated reactive oxygen species (ROS) stabilizes HIF-1α contributing to increase production of VEGF and MIF. Together the data indicate, that the ROS-HIF-1α signaling axis is very crucial in regulation of chemo-resistance by MNCs. Targeting ROS-HIF-1α in future may help to abrogate drug resistance in breast cancer.

BAG3 Overexpression and Cytoprotective Autophagy Mediate Apoptosis Resistance in Chemoresistant Breast Cancer Cells

Target-specific treatment modalities are currently not available for triple-negative breast cancer (TNBC), and acquired chemotherapy resistance is a primary obstacle for the treatment of these tumors. Here we employed derivatives of BT-549 and MDA-MB-468 TNBC cell lines that were adapted to grow in the presence of either 5-Fluorouracil, Doxorubicin or Docetaxel in an aim to identify molecular pathways involved in the adaptation to drug-induced cell killing. All six drug-adapted BT-549 and MDA-MB-468 cell lines displayed cross resistance to chemotherapy and decreased apoptosis sensitivity. Expression of the anti-apoptotic co-chaperone BAG3 was notably enhanced in two thirds (4/6) of the six resistant lines simultaneously with higher expression of HSP70 in comparison to parental controls. Doxorubicin-resistant BT-549 (BT-549^rDOX²⁰) and 5-Fluorouracil-resistant MDA-MB-468 (MDA-MB-468^r5-FU²⁰⁰⁰) cells were chosen for further analysis with the autophagy inhibitor Bafilomycin A1 and lentiviral depletion of ATG5, indicating that enhanced cytoprotective autophagy partially contributes to increased drug resistance and cell survival. Stable lentiviral BAG3 depletion was associated with a robust down-regulation of Mcl-1, Bcl-2 and Bcl-xL, restoration of drug-induced apoptosis and reduced cell adhesion in these cells, and these death-sensitizing effects could be mimicked with the BAG3/Hsp70 interaction inhibitor YM-1 and by KRIBB11, a selective transcriptional inhibitor of HSF-1. Furthermore, BAG3 depletion was able to revert the EMT-like transcriptional changes observed in BT-549^rDOX²⁰ and MDA-MB-468^r5-FU²⁰⁰⁰ cells. In summary, genetic and pharmacological interference with BAG3 is capable to resensitize TNBC cells to treatment, underscoring its relevance for cell death resistance and as a target to overcome therapy resistance of breast cancer.

Autophagy regulates cisplatin-induced stemness and chemoresistance via the upregulation of CD44, ABCB1 and ADAM17 in oral squamous cell carcinoma

OBJECTIVE

We inspected the relevance of CD44, ABCB1 and ADAM17 in OSCC stemness and deciphered the role of autophagy/mitophagy in regulating stemness and chemoresistance.

MATERIAL AND METHODS

A retrospective analysis of CD44, ABCB1 and ADAM17 with respect to the various clinico-pathological factors and their correlation was analysed in sixty OSCC samples. Furthermore, the stemness and chemoresistance were studied in resistant oral cancer cells using sphere formation assay, flow cytometry and florescence microscopy. The role of autophagy/mitophagy was investigated by transient transfection of siATG14, GFP-LC3, tF-LC3, mKeima-Red-Mito7 and Western blot analysis of autophagic and mitochondrial proteins.

RESULTS

In OSCC, high CD44, ABCB1 and ADAM17 expressions were correlated with higher tumour grades and poor differentiation and show significant correlation in their co-expression. In vitro and OSCC tissue double labelling confirmed that CD44⁺ cells co-expresses ABCB1 and ADAM17. Further, cisplatin (CDDP)-resistant FaDu cells displayed stem-like features and higher CD44, ABCB1 and ADAM17 expression. Higher autophagic flux and mitophagy were observed in resistant FaDu cells as compared to parental cells, and inhibition of autophagy led to the decrease in stemness, restoration of mitochondrial proteins and reduced expression of CD44, ABCB1 and ADAM17.

CONCLUSION

The CD44⁺ /ABCB1⁺ /ADAM17⁺ expression in OSCC is associated with stemness and chemoresistance. Further, this study highlights the involvement of mitophagy in chemoresistance and autophagic regulation of stemness in OSCC.

Pre-clinical risk assessment and therapeutic potential of antitumor lipopeptide ‘Iturin A’ in an in vivo and in vitro model

Microbial lipopeptide “Iturin A” is a versatile bio-active molecule with potent antitumor action. Pre-clinical study of this lipopeptide showed very minimum toxicity in rodent model.

Poly(3-methylthiophene)/graphene composite: in-situ synthesis and its electrochemical characterization

Poly(3-methylthiophene)/Graphene composites (G-PMT) and poly(3-methylthiophene) (PMT) were synthesized by in-situ chemical oxidative polymerization and investigated as electrode material for supercapacitors. The interaction between graphene and polymer chains was characterized by Fourier Transform Infrared (FTIR) spectroscopy. The morphology of the nanocomposites was characterized by Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (TEM). The thermal stability of the composite and the polymer was studied by Thermogravimetric Analysis (TGA) which shows G-PMT has higher thermal stability than PMT. The electrochemical properties were investigated by Cyclic Voltammetry (CV), Cyclic Charging-discharging tests (CC) and Electrochemical Impedance Spectroscopy (EIS) in a three-electrode system. G-PMT resulted in higher specific capacitance of 240 F/g. The specific capacitance retention after 500 cycles on G-PMT was also higher compared with PMT. These results indicate that G-PMT has good electrochemical performance than PMT hence it is useful for the making of electrode in supercapacitor application.

Doping effect of polyaniline/MWCNT composites on capacitance and cyclic stability of supercapacitors

Polyaniline doped by Zn2+ ions was synthesized as nanocomposites with multiwalled carbon nanotubes (MWCNT) by in-situ oxidative polymerization and investigated as electrode material for supercapacitors. The uniform coating of polyaniline on MWCNT was characterized by field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). The effect of Zn2+ ions on nanocomposites were characterized by Fourier transform infrared (FTIR) spectroscopy. The electrochemical performances were investigated by cyclic voltammetry (CV), constant current charging/discharging cyclic test (CC) and electrochemical impedance spectroscopy (EIS) using a three-electrode system. The doped polyaniline composites show higher specific capacitance and better cyclic stability.

Effect of modified MWCNT and polyphosphazene elastomer on the properties of PES/LCP blend system

PES/LCP/MWCNT nanocomposites were prepared through melt blending and the effect of Polyphosphazene elastomer as a compatibilizer was investigated. Fourier Transform Infrared Spectra (FTIR) exhibited that Carbon nanotubes (CNT's) were linked with PES. Field Emission Scanning Electron Microscopy (FESEM) micrographs highlighted the dispersion of CNT throughout the matrix and formation of network structure. Rheological analysis revealed the extent of interfacial adhesion. Thermal properties were characterized by Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). A remarkable increase in the magnitude of storage modulus (E') with the addition of MWCNTs was observed through Dynamic mechanical Thermal analysis (DMTA). Crystallinity of the concerned composites was assessed through X-Ray Diffraction (XRD) study. Tensile strength was observed to increase with increasing CNT content, whereas, % of elongation at break was found to decrease. But, in case of polyphosphazene-aided nanocomposite, % of elongation at break was found to increase reflecting the flexible behaviour of the composite.

Preparation and characterization of poly(methyl methacrylate)/multi-walled carbon nanotube composites

This paper focuses on the preparation and characterization of Poly(methyl methacrylate)/multi-walled carbon nanotube composites through ex-situ and in-situ processes. The extent of dispersion and fracture morphology was studied by TEM, AFM, SEM and FESEM. The increase in conductivity at percolated loading of 2.91 wt% was more for in-situ prepared PMMA/MWNTs nanocomposite as compared to ex-situ prepared nanocomposites. The dielectric constant of pure PMMA was increased from 5 to 72 in the ex-situ prepared PMMA/MWNTs nanocomposites with 4.76 wt% of MWNTs loading. Moreover, for the ex-situ nanocomposites containing 2.91 wt% of MWNTs, the dielectric constant was 15, but in-situ prepared PMMA/MWNTs nanocomposite showed two times increase at same loading of 2.91 wt% of MWNTs. Dielectric constant of PMMA/MWNTs nanocomposites loaded with (< 4.76 wt%) of MWNTs remained almost constant with frequency. Dynamic mechanical analysis showed remarkable increase in storage modulus, especially at higher temperatures with 4.76 wt% loading of carbon nanotubes as compared to pure PMMA. The presence of additional peak before T(g) indicated that CNTs could be used to wake up secondary relaxations, which were inactive in pure PMMA. Thermogravimetric analysis (TGA) showed that thermal stability of PMMA/MWNTs nanocomposites increased by 45 degrees C (in N2) and 27 degrees C (in air) at 4.76 wt% of MWNTs as compared to the pure PMMA.

Multi-walled carbon nanotubes/polymer composites in absence and presence of acrylic elastomer (ACM)

Polyetherimide/Multiwall carbon nanotube (MWNTs) nanocomposites containing as-received and modified (COOH-MWNT) carbon nanotubes were prepared through melt process in extruder and then compression molded. Thermal properties of the composites were characterized by thermo-gravimetric analysis (TGA). Field emission scanning electron microscopy (FESEM) images showed that the MWNTs were well dispersed and formed an intimate contact with the polymer matrix without any agglomeration. However the incorporation of modified carbon nanotubes formed fascinating, highly crosslinked, and compact network structure throughout the polymer matrix. This showed the increased adhesion of PEI with modified MWNTs. Scanning electron microscopy (SEM) also showed high degree of dispersion of modified MWNTs along with broken ends. Dynamic mechanical analysis (DMA) results showed a marginal increase in storage modulus (E') and glass transition temperature (T(g)) with the addition of MWNTs. Increase in tensile strength and impact strength of composites confirmed the use the MWNTs as possible reinforcement agent. Both thermal and electrical conductivity of composites increased, but effect is more pronounced on modification due to formation of network of carbon nanotubes. Addition of acrylic elastomer to developed PEI/MWNTs (modified) nanocomposites resulted in the further increase in thermal and electrical properties due to the formation of additional bond between MWNTs and acrylic elastomers at the interface. All the results presented are well corroborated by SEM and FESEM studies.

Synergistic effect of nanoclay and EPR-g-MA on the properties of nylon6/EPR blends

The effect of EPR-g-MA, nanoclay and a combination of the two on phase morphology and properties of (70/30 w/w) nylon6/EPR blends prepared by melt processing technique has been studied. We found that the number average domain diameter (D(n)) of the dispersed EPR phase in the blend decreased in presence of EPR-g-MA, and clay. This observation indicated that nanoclay could be used as an effective compatibilizer in nylon6/EPR blend. X-ray diffraction study and TEM analysis of the blend/clay nanocomposites revealed the delaminated clay morphology and preferential location of the exfoliated clay platelets in nylon6 phase. Thus, selective dispersion of the clay platelets with delaminated morphology in the matrix phase acted as the barrier and thereby prevented the coalescence of dispersed EPR domains during melt processing. However, addition of nanoclay in the blend did not improve the impact property of the blend. Interestingly, the impact strength of the nylon6/EPR/EPR-g-MA/clay blend was much higher than the nylon6/EPR/EPR-g-MA and nylon6/EPR/clay blends at certain compositions with comparable D(n) values. This could be explained by assuming the presence of delaminated clay platelets at the interface, which were stiffer than the polymers. Hence, the bending energy of the interfaces was high.

Idiopathic hypertrophic cranial pachymeningitis

Idiopathic hypertrophic cranial pachymeningitis is a rare form of fibrosing chronic inflammatory process of unknown etiology, which causes thickening of the intracranial dura mater. We present four patients with hypertrophic cranial pachymeningitis who presented with chronic headache and cranial nerve palsies. The diagnosis of idiopathic hypertrophic cranial pachymeningitis was based on neuroimaging findings of thickened enhancing dura, exclusion of known causes and histopathologic findings compatible with nonspecific inflammation in the meningeal biopsies. Corticosteroid therapy was effective in all cases in inducing a complete or partial remission of the neurologic symptoms and signs. We describe the clinical, radiological and pathological features of idiopathic hypertrophic cranial pachymeningitis and discuss the relationship of this entity with other inflammatory fibrosclerotic disorders to explain the pathogenesis. A high index of suspicion, prompt confirmation of the diagnosis by meningeal biopsy, and early institution and long-term maintenance of steroid therapy may help to prevent irreversible neurologic sequelae, especially blindness.

Thioredoxin, a singlet oxygen quencher and hydroxyl radical scavenger: redox independent functions

Thioredoxin is a ubiquitous small protein known to protect cells and tissues against oxidative stress. However, its exact antioxidant nature has not been elucidated. In this report, we present evidence that human thioredoxin is a powerful singlet oxygen quencher and hydroxyl radical scavenger. Human thioredoxin at 3 microM caused 50% inhibition of TEMP-(1)O(2) (TEMPO) adduct formation in a photolysis EPR study. In contrast, Escherichia coli thioredoxin caused 50% inhibition of TEMPO formation at 80 microM. Both E. coli thioredoxin and human thioredoxin inhibited (*)OH dependent DMPO-OH formation as demonstrated by EPR spectrometry. The quenching of (1)O(2) or scavenging of (*)OH was not dependent upon the redox state of thioredoxin. Using a human thioredoxin in which the structural cysteines were mutated to alanine, Trx-C3A, we show that structural cysteines that do not take part in the catalytic functions of the protein are also important for its reactive oxygen scavenging properties. In addition, using a quadruple mutant Trx-C4A, where one of the catalytic cysteines, C35 was mutated to alanine in addition to the mutated structural cysteines, we demonstrated that catalytic cysteines are also required for the scavenging action of thioredoxin. Identification of thioredoxin as a (1)O(2) quencher and (*)OH scavenger may be of significant importance in explaining various redox-related antioxidant functions of thioredoxin.

Poisoning in children: Indian scenario

The retrospective data on childhood poisoning from eight regional hospitals in India has been reviewed. The demographic features and types of poisonings encountered have been compared. The analysis of the data indicated that pediatric poisonings constituted 0.23-3.3% of the total poisoning. The mortality ranged from 0.64-11.6% with highest being from Shimla. Accidental poisoning was common involving 50-90% of children below 5 years of age and males outnumbered the females. Suicidal poisoning was seen after 13 years of age and was due to drugs and household chemicals. One of the hospitals in Delhi recorded a very high incidence (66.6%) of drug poisoning in children. The drugs consumed belonged to phenothiazines, antiepileptics and antipyretics. Iron poisoning was seen in younger children. Kerosene was one of the causes of accidental poisoning at all hospitals except Shimla and rural Maharashtra were probably wood charcoal is widely used. Pesticide poisoning was more prevalent in Punjab and West Bengal whereas plant poisoning was very common in Shimla. Significant number of snake envenomation has been recorded from rural Maharashtra. Other less common accidental poisonings in children included alcohol, corrosives, heavy metals, rodenticides, detergents and disinfectants. Thus various regions in the country showed some variation in types and frequency of childhood poisoning which could be attributed to different geographical and socio-economic background.

Hemoglobin E disease in pregnancy

Abnormal hemoglobin patterns such as hemoglobin-E are rarely found in Western populations. The condition is fairly common in Southeast Asian countries such as Thailand, however. It is not commonly found in West Asian countries such as Saudi Arabia. A case report of hemoglobin E disease in pregnancy is made; its impact on pregnancy and labor is discussed.

Cardiac failure in pregnant Northern Nigerian women

Thirty-nine gravidae with congestive cardiac failure and ten pregnant patients with acute pulmonary edema treated at the Ahmadu Bello University Teaching Hospital in Kaduna, Nigeria, over a five-year period are presented. Congestive cardiac failure occurred more frequently in the postnatal period, and parity and socioeconomic class were not significantly related to cardiac failure. Maternal mortality was low in spite of all patients being in functional grades III and IV. Idiopathic cardiomegaly and chronic rheumatic heart disease were the most common underlying causes of heart failure in pregnancy. The dominant valvular lesions in the patients with rheumatic heart disease was mitral incompetence.

Mixed mesodermal tumour of the cervix uteri. Case report

A 44-year-old African female with a mixed mesodermal tumour of the cervix is described and the literature briefly reviewed.