Adipose tissue derived mesenchymal stem cells are better respondents to TGFß1 for in vitro generation of cardiomyocyte-like cells.

Mesenchymal stem cells (MSCs) are multipotent cells which hold immense potential in translational research as a novel treatment modality. In recent years, MSCs isolated from various tissues have been used in several clinical trials for the treatment of cardiac injury caused by permanent myocardial loss. However, a better MSCs source and an optimum inducer for in vitro cardiac differentiation are still far reaching and unexplored. The aim of the study was to compare the ability and efficiency of differentiation of MSCs isolated from bone marrow (BM-MSCs) and adipose tissue (ADSC) into cardiomyocyte-like cells to aid translational research. To fulfill this aim, freshly isolated BM-MSCs and ADSCs were differentiated into cardiomyocytes using 5-Azacytidine (6 µM) and TGF-ß1 (25 ng/ml). These two differentiation protocols were compared on the basis of morphological, transcriptional, translational and functionality analysis. Both tissue specific MSCs, ADSCs and BM-MSCs, have similar surface marker profile and population doubling time. In both the treatment regimes, BM-MSCs and ADSCs showed morphological changes like flattening of cells and myotube formation in concurrence with structure and multinucleation, with early sign of differentiation in ADSCs. Further, the expression of cardiac specific markers including myosin light chain-2v (Mlc-2v), cardiac troponin I (cTnI), and sarco/endoplasmic reticulum Ca2+-ATPase (SerCa2) were higher in AD-TGFß1 group, both at transcriptional and translational level. During functionality analysis by KCl stimulation, increased intracellular calcium fluorescence was observed in AD- TGFß1 group as compared to others. Thus, ADSCs proved to be a better choice for stem cell therapy in cardiovascular diseases when induced with TGF-ß1.

Silencing growth hormone receptor inhibits estrogen receptor negative breast cancer through ATP-binding cassette sub-family G member 2.

Growth hormone receptor (GHR) plays a vital role in breast cancer chemoresistance and metastasis but the mechanism is not fully understood. We determined if GHR could be a potential therapeutic target for estrogen receptor negative (ER-ve) breast cancer, which are highly chemoresistant and metastatic. GHR was stably knocked down in ER-ve breast cancer cells and its effect on cell proliferation, metastatic behavior, and chemosensitivity to docetaxel (DT) was assessed. Microarray analysis was performed to identify potential GHR downstream targets involved in chemoresistance. GHR and ATP-binding cassette sub-family G member 2 (ABCG2) overexpression and knockdown studies were performed to investigate the mechanism of GHR-induced chemoresistance. Patient-derived xenografts was used to study the effect of GHR and ABCG2. Immunohistochemical data was used to determine the correlation between GHR, pAKT, pmTOR, and ABCG2 expressions. GHR silencing drastically reduced the chemoresistant and metastatic behavior of ER-ve breast cancer cells and also inhibited AKT/mTOR pathway. In contrast, activation, or overexpression of GHR increased chemoresistance and metastasis by increasing the expression and promoter activity, of ABCG2. Inhibition of JAK2/STAT5 signaling repressed GHR-induced ABCG2 promoter activity and expression. Further, ABCG2 knockdown significantly increased the chemosensitivity. Finally, patient-derived xenograft studies revealed the role of GHR in chemoresistance. Overall, these findings demonstrate that targeting GHR could be a novel therapeutic approach to overcome chemoresistance and associated metastasis in aggressive ER-ve breast cancers.

Iron oxide labeling does not affect differentiation potential of human bone marrow mesenchymal stem cells exhibited by their differentiation into cardiac and neuronal cells.

Mesenchymal stem cells (MSCs) have shown promising outcomes in cardiac and neuronal diseases. Efficient and noninvasive tracking of MSCs is essential to harness their therapeutic potential. Iron oxide nanoparticles (IONPs) have emerged as effective means to label stem cells and visualize them using magnetic resonance imaging (MRI). It is known that IONPs do not affect viability and cell proliferation of stem cells. However, very few studies have demonstrated differentiation potential of iron oxide-labeled MSCs and their differentiation into specific lineages that can contribute to cellular therapies. The differentiation of IONP-labeled human bone marrow mesenchymal stem cells (hBM-MSCs) into cardiac and neuronal lineages has never been studied. In this study, we have shown that IONP-labeled hBM-MSCs retain their differentiation potential to cardiac and neuronal cell lineages. We also confirmed that labeling hBM-MSCs with IONP does not affect their characteristic properties such as viability, cellular proliferation rate, surface marker profiling, and trilineage differentiation capacity. This study shows that IONP can be efficiently tracked, and its labeling does not alter stemness and differentiation potential of hBM-MSCs. Thus, the labeled hBM-MSCs can be used in clinical therapies and regenerative medicine.

Cancer Stem Cells and Metastasis.

Decades of cancer research have led to substantial progress in the treatment of primary breast cancers. Despite of the advancement in this field, treating a metastatic disease has remained a mammoth task. One of the possible theories explaining metastatic disease involves the cancer stem cells (CSCs). CSCs have been shown to be an integral part of solid tumors. The process of metastasis involves the fine orchestration between CSCs and other microenvironmental factors. This chapter will provide an overview about the process of metastasis and the interactive role of CSCs with the components of the microenvironment in each phase of the metastatic cascade.

Glucose insult elicits hyperactivation of cancer stem cells through miR-424-cdc42-prdm14 signalling axis.

BACKGROUND: Meta-analysis shows that women with diabetes have a 20% increased risk of breast cancer and also an increased risk for distant metastasis and mortality. The molecular mechanisms for distant metastasis and mortality in breast cancer patients with diabetes are not very well understood. METHODS: We compared the effect of physiological (5 mM) and diabetic (10 mM) levels of glucose on malignant breast epithelial cell invasion and stemness capabilities. We performed microRNA array to determine the dysregulated microRNAs in hyperglycaemic conditions and performed functional and molecular analysis of the gene targets. RESULTS: Hyperglycaemia leads to hyperactivation of cancer stem cell pool and enhances invasive ability of breast cancer cells. MiR-424 seems to be a key regulator of cancer cell stemness and invasion. Knockdown of miR-424 in cancer cells under euglycaemic conditions leads to enhanced invasion and stem cell activity, whereas ectopic expression of miR-424 in cancer cells under hyperglycaemic conditions results in suppressed invasion and stem cell activity. Cdc42, a target of miR-424, influences cancer stem cell activity by positively regulating prdm14 through activation of pak1 (p-21-activated kinase 1) and stat5. CONCLUSIONS: Our findings establish miR-424→︀cdc42→︀prdm14 axis as a key molecular signalling cascade that might influence breast cancer progression in diabetic patients through hyperactivation of cancer stem cells.

Role of Growth Hormone in Breast Cancer.

Breast cancer is one of the most common cancers diagnosed in women. Approximately two-thirds of all breast cancers diagnosed are classified as hormone dependent, which indicates that hormones are the key factors that drive the growth of these breast cancers. Ovarian and pituitary hormones play a major role in the growth and development of normal mammary glands and breast cancer. In particular, the effect of the ovarian hormone estrogen has received much attention in regard to breast cancer. Pituitary hormones prolactin and growth hormone have also been associated with breast cancer. Although the role of these pituitary hormones in breast cancers has been studied, it has not been investigated extensively. In this review, we attempt to compile basic information from most of the currently available literature to understand and demonstrate the significance of growth hormone in breast cancer. Based on the available literature, it is clear that growth hormone plays a significant role in the development, progression, and metastasis of breast cancer by influencing tumor angiogenesis, stemness, and chemoresistance.

Gedunin inhibits pancreatic cancer by altering sonic hedgehog signaling pathway.

INTRODUCTION: The lack of efficient treatment options for pancreatic cancer highlights the critical need for the development of novel and effective chemotherapeutic agents. The medicinal properties found in plants have been used to treat many different illnesses including cancers. This study focuses on the anticancer effects of gedunin, a natural compound isolated from Azadirachta indica. METHODS: Anti-proliferative effect of gedunin on pancreatic cancer cells was assessed using MTS assay. We used matrigel invasion assay, scratch assay, and soft agar colony formation assay to measure the anti-metastatic potential of gedunin. Immunoblotting was performed to analyze the effect of gedunin on the expression of key proteins involved in pancreatic cancer growth and metastasis. Gedunin induced apoptosis was measured using flow cytometric analysis. To further validate, xenograft studies with HPAC cells were performed. RESULTS: Gedunin treatment is highly effective in inducing death of pancreatic cancer cells via intrinsic and extrinsic mediated apoptosis. Our data further indicates that gedunin inhibited metastasis of pancreatic cancer cells by decreasing their EMT, invasive, migratory and colony formation capabilities. Gedunin treatment also inhibited sonic hedgehog signaling pathways. Further, experiments with recombinant sonic hedgehog protein and Gli inhibitor (Gant-61) demonstrated that gedunin induces its anti-metastatic effect through inhibition of sonic hedgehog signaling. The anti-cancer effect of gedunin was further validated using xenograft mouse model. CONCLUSION: Overall, our data suggests that gedunin could serve as a potent anticancer agent against pancreatic cancers.

The serum protein profile of early parity which induces protection against breast cancer.

Early parity reduces the risk of breast cancer in women while nulliparity and late parity increase the risk of breast cancer. In order to translate this protection to women where early pregnancy is not feasible, much work has focused on understanding how parity confers protection against breast cancer, the molecular mechanisms by which this occurs is still not well understood. Healthy parous and nulliparous women were recruited for this study. We assessed serum protein profiles of early parous, late parous, and nulliparous women using the Phospho Explorer antibody array. Significantly altered proteins identified were validated by Western blot analysis. In silico analysis was performed with the data obtained. Our findings indicate increased phosphorylation levels of CDK1, AKT1 and Epo-R increased cell cycle and cell proliferation in late/nulliparous women. Increased levels of LIMK1, paxillin, caveolin-1, and tyrosine hydroxylase in late/nulliparous women demonstrate enhanced cell stress while decreased activity of p-p53 and pRAD51 in late/nulliparous women indicates decreased apoptosis and increased genomic instability. Further, increased levels of pFAK, pCD3zeta, pSTAT5B, MAP3K8 in early parous women favor enhanced innate/adaptive immunity. Overall, we have identified a unique protein signature that is responsible for the decreased risk of breast cancer and these proteins can also serve as biomarkers to predict the risk of breast cancer.

Hair & skin derived progenitor cells: In search of a candidate cell for regenerative medicine.

BACKGROUND & OBJECTIVES: Skin is an established tissue source for cell based therapy. The hair follicle has been introduced later as a tissue source for cell based therapy. The ease of tissue harvest and multipotent nature of the resident stem cells in skin and hair follicle has promoted basic and clinical research in this area. This study was conducted to evaluate skin stem cells (SSCs) and hair follicle stem cells (HFSCs) as candidate cells appropriate for neuronal and melanocyte lineage differentiation. METHODS: In this study, SSCs and hair follicle stem cells (HFSCs) were expanded in vitro by explant culture method and were compared in terms of proliferative potential and stemness; differentiation potential into melanocytes and neuronal lineage. RESULTS: SSCs were found to be more proliferative in comparison to HFSCs, however, telomerase activity was more in HFSCs in comparison to SSCs. Capacity to differentiate into two lineages of ectoderm origin (neuronal and melanocyte) was found to be different. HFSCs cells showed more propensities towards melanocyte lineage, whereas SSCs were more inclined towards neuronal lineage. INTERPRETATION & CONCLUSIONS: The study showed that SSCs had differential advantage over the HFSCs for neuronal cell differentiation, whereas, the HFSCs were better source for melanocytic differentiation.

Nimbolide inhibits pancreatic cancer growth and metastasis through ROS-mediated apoptosis and inhibition of epithelial-to-mesenchymal transition.

The mortality and morbidity rates of pancreatic cancer are high because of its extremely invasive and metastatic nature. Its lack of symptoms, late diagnosis and chemo-resistance and the ineffective treatment modalities warrant the development of new chemo-therapeutic agents for pancreatic cancer. Agents from medicinal plants have demonstrated therapeutic benefits in various human cancers. Nimbolide, an active molecule isolated from Azadirachta indica, has been reported to exhibit several medicinal properties. This study assessed the anticancer properties of nimbolide against pancreatic cancer. Our data reveal that nimbolide induces excessive generation of reactive oxygen species (ROS), thereby regulating both apoptosis and autophagy in pancreatic cancer cells. Experiments with the autophagy inhibitors 3-methyladenine and chloroquine diphosphate salt and the apoptosis inhibitor z-VAD-fmk demonstrated that nimbolide-mediated ROS generation inhibited proliferation (through reduced PI3K/AKT/mTOR and ERK signaling) and metastasis (through decreased EMT, invasion, migration and colony forming abilities) via mitochondrial-mediated apoptotic cell death but not via autophagy. In vivo experiments also demonstrated that nimbolide was effective in inhibiting pancreatic cancer growth and metastasis. Overall, our data suggest that nimbolide can serve as a potential chemo-therapeutic agent for pancreatic cancer.

Desacetyl nimbinene inhibits breast cancer growth and metastasis through reactive oxygen species mediated mechanisms.

Accumulation of reactive oxygen species (ROS) has been implicated in induction of apoptosis and regulation of key signaling molecules in cancer cells. Phytochemicals are potent source of anticancer drugs as wells as potential inducers of ROS. Neem (Azadirachta indica) is a medicinal plant used for the treatment of various diseases. The main objective of this study is to investigate the anticancer effect of desacetyl nimbinene (DAN; an active ingredient of neem) against breast cancer. Normal and breast cancer cell lines were used for the study. The effect of DAN on cell proliferation, apoptosis, ROS generation, migration, and invasion was analyzed. Antioxidant enzymes superoxide dismutase (SOD)1 and SOD2 were overexpressed to test the effect of DAN-induced ROS generation on breast cancer growth. Key survival and apoptotic protein markers were analyzed to validate the anticancer effect of DAN. Our data demonstrated that DAN inhibited the growth of breast cancer cells by inducing ROS generation. Further investigations revealed that DAN treatment lead to the loss of mitochondrial membrane potential resulting in mitochondria-dependent apoptotic cell death. Increased phosphorylation of c-Jun-N-terminal kinase (JNK) and reduced phosphorylation of p38 were also observed in response to DAN treatment. Inhibition of ROS production by overexpressing antioxidant enzymes SOD1 and SOD2 reduced the DAN-induced cytotoxicity. Additionally, DAN significantly inhibited migration and invasion of MDA-MB-231 breast cancer cells. Overall, our data suggest that DAN exerts its anticancer effect on breast cancer by induction of mitochondria-mediated apoptosis mediated by ROS accumulation.

A Breast Tissue Protein Expression Profile Contributing to Early Parity-Induced Protection Against Breast Cancer.

BACKGROUND/AIMS: Early parity reduces breast cancer risk, whereas, late parity and nulliparity increase breast cancer risk. Despite substantial efforts to understand the protective effects of early parity, the precise molecular circuitry responsible for these changes is not yet fully defined. METHODS: Here, we have conducted the first study assessing protein expression profiles in normal breast tissue of healthy early parous, late parous, and nulliparous women. Breast tissue biopsies were obtained from 132 healthy parous and nulliparous volunteers. These samples were subjected to global protein expression profiling and immunohistochemistry. GeneSpring and MetaCore bioinformatics analysis software were used to identify protein expression profiles associated with early parity (low risk) versus late/nulliparity (high risk). RESULTS: Early parity reduces expression of key proteins involved in mitogenic signaling pathways in breast tissue through down regulation of EGFR1/3, ESR1, AKT1, ATF, Fos, and SRC. Early parity is also characterized by greater genomic stability and reduced tissue inflammation based on differential expression of aurora kinases, p53, RAD52, BRCA1, MAPKAPK-2, ATF-1, ICAM1, and NF-kappaB compared to late and nulli parity. CONCLUSIONS: Early parity reduces basal cell proliferation in breast tissue, which translates to enhanced genomic stability, reduced cellular stress/inflammation, and thus reduced breast cancer risk.

Emerging roles of microRNAs in pancreatic cancer diagnosis, therapy and prognosis (Review).

Pancreatic cancer is one of the leading causes of cancer related death. Increasing incidence and mortality indicates a lack of detection and post diagnostic management of this disease. Recent evidences suggest that, miRNAs are very attractive target molecules that can serve as biomarkers for predicting development and progression of pancreatic cancer. Furthermore, miRNAs are also promising therapeutic targets for pancreatic cancer. The objective of the present review is to discuss the significance of miRNA in pancreatic cancer development, diagnosis, therapy and prognosis. We extracted and compiled the useful information from PubMed database, which satisfied our criteria for analysis of miRNAs in pancreatic cancer diagnosis, therapy and prognosis. A summary of the most important miRNAs known to regulate pancreatic tumorigenesis is provided. The review also provides a collection of evidence that show miRNA profiles of biofluids hold much promise for use as biomarkers to predict and detect development of pancreatic cancer in its early stages. Identification of key miRNA networks in pancreatic cancer will provide long-awaited diagnostic/therapeutic/prognostic tools for early detection, better treatment options, and extended life expectancy and quality of life in PDAC patients.

MicroRNA-125a influences breast cancer stem cells by targeting leukemia inhibitory factor receptor which regulates the Hippo signaling pathway.

Cancer stem cells (CSC) are the main driving force behind cancer initiation and progression. The molecular mechanisms that regulate CSC properties are poorly understood. MicroRNAs (miRNAs) play a significant role in normal and cancer tissues. Here, we show that miRNA-125a indirectly regulates TAZ, an effector molecule in the Hippo pathway, through the leukemia inhibitory factor receptor (LIFR). The miR-125a→LIFR axis affected the homeostasis of nonmalignant and malignant breast epithelial stem cells through the Hippo signaling pathway. Inhibition of miR-125a in breast cancer cells led to a significant reduction in the CSC pool. In contrast, enhanced expression of miR-125a in nonmalignant breast epithelial cells resulted in significant expansion of the stem cell pool. Gain of function and loss of function of LIFR directly correlated with the inhibition and overexpression of miR-125a, respectively. Modulation of miR-125a led to a change in the activity of TAZ and its subcellular localization. We further demonstrated that miR-125a influenced stem cells by regulating Hippo signaling through LIFR in human primary breast cancer cells confirming the data obtained from established cell lines. We suggest that miR-125a could be a potential target against CSCs that maybe used along with the existing conventional therapies.

Recurrence and metastasis of breast cancer is influenced by ovarian hormone's effect on breast cancer stem cells.

Cancer stem cells (CSCs) have recently attracted great interest because of their emerging role in initiation, progression and metastasis, combined with their intrinsic resistance to chemotherapy and radiation therapy. CSCs and its interaction with hormones in breast cancer are currently being investigated with the aim of uncovering the molecular mechanisms by which they evade conventional treatment regimens. In this review, we discuss recent experimental data and new perspectives in the area of steroid hormones and their cross-talk with breast CSCs. We have covered literature associated with biomarkers, hormone receptors and hormone responsive signaling pathways in breast CSC. In addition, we also discuss the role of miRNAs in hormone mediated regulation of breast CSCs.

Growth hormone receptor inhibition decreases the growth and metastasis of pancreatic ductal adenocarcinoma.

Pancreatic cancer is the only major cancer with very low survival rates (1%). It is the fourth leading cause of cancer-related death. Hyperactivated growth hormone receptor (GHR) levels have been shown to increase the risk of cancer in general and this pathway is a master regulator of key cellular functions like proliferation, apoptosis, differentiation, metastasis, etc. However, to date there is no available data on how GHR promotes pancreatic cancer pathogenesis. Here, we used an RNA interference approach targeted to GHR to determine whether targeting GHR is an effective method for controlling pancreatic cancer growth and metastasis. For this, we used an in vitro model system consisting of HPAC and PANC-1 pancreatic cancer cells lines. GHR is upregulated in both of these cell lines and silencing GHR significantly reduced cell proliferation and viability. Inhibition of GHR also reduced the metastatic potential of pancreatic cancer cells, which was aided through decreased colony-forming ability and reduced invasiveness. Flow cytometric and western blot analyses revealed the induction of apoptosis in GHR silenced cells. GHR silencing affected phosphatidylinositol 3 kinase/AKT, mitogen extracellular signal-regulated kinase/extracellular signal-regulated kinase, Janus kinase/signal transducers and activators of transcription and mammalian target of rapamycin signaling, as well as, epithelial to mesenchymal transition. Interestingly, silencing GHR also suppressed the expression of insulin receptor-ß and cyclo-oxygenease-2. Altogether, GHR silencing controls the growth and metastasis of pancreatic cancer and reveals its importance in pancreatic cancer pathogenesis.

Fibroblast Growth Factor-2 alone as an efficient inducer for differentiation of human bone marrow mesenchymal stem cells into dopaminergic neurons.

BACKGROUND: The reported efficiency of differentiation of human bone marrow derived Mesenchymal Stem Cells (hBM MSC) into dopaminergic neurons with different inducers is found to vary. Thus, in the current study we have investigated the response of hBM MSC to some of the neuronal inducers and their combinations. Neuronal differentiation inducing agents Fibroblastic Growth Factor 2 (FGF2), Sonic Hedge Hog (Shh), Fibroblastic Growth Factor 8 (FGF8) & All Trans Retinoic Acid (ATRA) were used either singly or in varied combinations. RESULTS: The differentiated and undifferentiated hBM MSC were characterized in terms of morphology, expression of cell markers at transcriptional and translational levels, amount of dopamine secreted by the cells in the media and changes in cell membrane potential by calcium ions imaging. Induced hBM MSC revealed neuron like morphology and expressed cellular markers suggesting neuronal differentiation with all the inducing agents. However, upon quantitative analysis through qPCR, cells induced with FGF2 were found to show maximum expression of tyrosine hydroxylase (TH) by 47.5 folds. Immunofluorescence analysis of differentiated and undifferentiated cells also revealed expression of nestin, neurofilament, microtubule associated protein- 2, beta tubulin III and TH in differentiated cells, at translational level. This data was supported by immunoblotting analysis. Further, ELISA study also supported the release of dopamine by cultures induced with FGF2. When the cells were depolarised with KCl solution, those induced with Shh & FGF8 showed maximum calcium ion trafficking, followed by the cells induced with FGF2 only. CONCLUSIONS: We conclude that hBM MSC can be coaxed to differentiate efficiently into dopaminergic neurons in the presence of a very simple media cocktail containing only one main inducer like FGF2 and thus contribute towards cellular therapy in Parkinson's and other related disorders. These dopaminergic neurons are also functionally active, as shown by calcium ion trafficking.

microRNA alterations in ALDH positive mammary epithelial cells: a crucial contributing factor towards breast cancer risk reduction in case of early pregnancy.

BACKGROUND: microRNAs have recently succeeded in grabbing the center stage in cancer research for their potential to regulate vital cellular process like cell cycle, stem cell renewal and epithelial mesenchymal transition. Breast cancer is the second most leading cause of cancer related mortality in women. The main reason for mortality is chemoresistance and metastasis for which remnant stem cells are believed to be the cause. One of the natural ways to reduce the risk of breast cancer in women is early pregnancy. Unraveling the mechanism behind it would add to our knowledge and help in evolving newer paradigms for breast cancer prevention.The current study deals with investigating transcriptomic differences in putative stem cells in mammary epithelial cell population (MECs) in terms of genes and microRNAs. In silico tools were used to identify potential mechanisms. ALDH positive MECs represent a putative stem cell population in the mammary gland. METHODS: MECs were extracted from the mammary gland of virgin and parous (one time pregnant) rats. ALDH positive MECs were sorted and used for transcriptional and translational analysis for genes and microRNAs. In silico analysis for target prediction and networking was performed through online portals of Target Scan and Metacore. RESULTS: A total of 35 and 49 genes and microRNAs respectively were found to be differentially expressed within the two groups. Among the important genes were Lifr, Acvr1c, and Pparγ which were found to be targeted by microRNAs in our dataset like miR-143, miR-30, miR-140, miR-27b, miR-125a, miR-128ab, miR-342, miR-26ab, miR-181, miR-150, miR-23ab and miR-425. In silico data mining and networking also demonstrates that genes and microRNA interaction can have profound effects on stem cell renewal, cell cycle dynamics and EMT processes of the MEC population. CONCLUSIONS: Our data clearly shows that certain microRNAs play crucial role in the regulation of ALDH positive MECs and favor an anti-carcinogenic environment in the post-partum gland. Some of the potential interplaying mechanisms in the ALDH positive MEC population identified through this study are p21, Lifr and Pparγ mediated cell cycle regulation, regulation of metastasis and expansion of stem cell pool respectively.

Parity and short-term estradiol treatment utilizes similar cellular mechanisms to confer protection against breast cancer.

BACKGROUND: Protective effect of early pregnancy and short-term estrogen treatment (STET), against breast cancer is well established. The underlying mechanisms are not well understood. In this study, we compared the mammary gland cellular microenvironment influenced/induced by parity and STET alongside age-matched controls. METHODS: Parous, STET, and control rats were injected with N-methyl-N-nitrosourea at 15 weeks and monitored for the development of mammary cancer. A subset of 4 rats were killed five weeks post carcinogen treatment and mammary gland samples were isolated and subjected to molecular analysis. RESULTS: Our results demonstrated a reduction in cell survival, extracellular matrix associated proliferation, hormonal and growth factor receptor pathways in the experimental groups compared to control rats. Moreover, concomitant reductions in the EMT markers along with cell migration regulators were also observed in parous and STET groups. Hormonal receptor such as GHR, PR, ERα and growth factor receptors IGFR, EGFR and erbB2 were down regulated in the treatment groups. Further analysis revealed that parity and STET drastically reduced the expression, activation of JAK2 and nuclear localization of STATs. CONCLUSION: Parity and STET by targeting major cell signaling pathways involved in cell survival, cell migration and cell death reduces the mammary tumor promoting environment.

Targeting insulin-like growth factor 1 receptor inhibits pancreatic cancer growth and metastasis.

Pancreatic cancer is one of the most lethal cancers. Increasing incidence and mortality indicates that there is still much lacking in detection and management of the disease. This is partly due to a lack of specific symptoms during early stages of the disease. Several growth factor receptors have been associated with pancreatic cancer. Here, we have investigated if an RNA interference approach targeted to IGF-IR could be effective and efficient against pancreatic cancer growth and metastasis. For that, we evaluated the effects of IGF-1R inhibition using small interfering RNA (siRNAs) on tumor growth and metastasis in HPAC and PANC-1 pancreatic cancer cell lines. We found that silencing IGF-1R inhibits pancreatic cancer growth and metastasis by blocking key signaling pathways such AKT/PI3K, MAPK, JAK/STAT and EMT. Silencing IGF-1R resulted in an anti-proliferative effect in PANC-1 and HPAC pancreatic cancer cell lines. Matrigel invasion, transwell migration and wound healing assays also revealed a role for IGF-1R in metastatic properties of pancreatic cancer. These results were further confirmed using Western blotting analysis of key intermediates involved in proliferation, epithelial mesenchymal transition, migration, and invasion. In addition, soft agar assays showed that silencing IGF-1R also blocks the colony forming capabilities of pancreatic cancer cells in vitro. Western blots, as well as, flow cytometric analysis revealed the induction of apoptosis in IGF-1R silenced cells. Interestingly, silencing IGF-1R also suppressed the expression of insulin receptor ß. All these effects together significantly control pancreatic cancer cell growth and metastasis. To conclude, our results demonstrate the significance of IGF-1R in pancreatic cancer.