Project description:Pancreatic ductal adenocarcinoma (PDAC) is one of the most intractable malignancies and systematic chemotherapies are the most commonly-used standard treatment for PDAC patients diagonosed at advanced stages. However, drug resistance may arise as early as several weeks after chemotherapy initiation, thus limiting the therapeutic efficacy of chemotherapy reagents. Accumulating evidence has demonstrated that acquired tolerance to apoptotic cell death induced by cytotoxic drugs is one of the critical reasons for the failure of chemotherapy. Ferroptosis was originally identified as a unique form of programmed cell death, which is characterized by shrunk mitochondria accompanied with condensed membranes and decreased crista, in drug screens searching for small molecules that can selectively kill RAS-expressing cancer cells. Unlike apoptosis, ferroptosis is driven by iron-catalyzed excessive lipid peroxidation, ultimately leading to the rupture of plasma membrane and cell death. Recent studies indicated that ferroptosis induction can be a promising therapeutic strategy in cancer treatment since it not only can kill tumor cells directly but also can synergize with chemotherapy ,radiotherapy,targeted therapy and immunotherapy. However, transformed malignant cells can acquired resistance to ferroptosis through adaptative changes in their epigenome, genome, transcriptome, translatome or proteome. Multiple mechanisms, such as decreased coenzyme Q10 production mediated by the upregulation of apoptosis-inducing factor mitochondria-associated 2 (AIFM2/FSP1) and elevated expression of cytoprotective genes as a result of the activation of antioxidant transcription factor NFE2L2/NRF2 (nuclear factor erythroid 2-like 2), have been demonstrated to confer ferroptosis resistance. However, transformed malignant cells can acquired resistance to ferroptosis through adaptative changes in their epigenome, genome, transcriptome, translatome or proteome. Multiple mechanisms, such as decreased coenzyme Q10 production mediated by the upregulation of apoptosis-inducing factor mitochondria-associated 2 (AIFM2/FSP1) and elevated expression of cytoprotective genes as a result of the activation of antioxidant transcription factor NFE2L2/NRF2 (nuclear factor erythroid 2-like 2), have been demonstrated to confer ferroptosis resistance.
Project description:Pancreatic ductal adenocarcinoma (PDAC) is one of the most intractable malignancies and systematic chemotherapies are the most commonly-used standard treatment for PDAC patients diagonosed at advanced stages. However, drug resistance may arise as early as several weeks after chemotherapy initiation, thus limiting the therapeutic efficacy of chemotherapy reagents. Accumulating evidence has demonstrated that acquired tolerance to apoptotic cell death induced by cytotoxic drugs is one of the critical reasons for the failure of chemotherapy. Ferroptosis was originally identified as a unique form of programmed cell death, which is characterized by shrunk mitochondria accompanied with condensed membranes and decreased crista, in drug screens searching for small molecules that can selectively kill RAS-expressing cancer cells. Unlike apoptosis, ferroptosis is driven by iron-catalyzed excessive lipid peroxidation, ultimately leading to the rupture of plasma membrane and cell death. Recent studies indicated that ferroptosis induction can be a promising therapeutic strategy in cancer treatment since it not only can kill tumor cells directly but also can synergize with chemotherapy ,radiotherapy,targeted therapy and immunotherapy. However, transformed malignant cells can acquired resistance to ferroptosis through adaptative changes in their epigenome, genome, transcriptome, translatome or proteome. Multiple mechanisms, such as decreased coenzyme Q10 production mediated by the upregulation of apoptosis-inducing factor mitochondria-associated 2 (AIFM2/FSP1) and elevated expression of cytoprotective genes as a result of the activation of antioxidant transcription factor NFE2L2/NRF2 (nuclear factor erythroid 2-like 2), have been demonstrated to confer ferroptosis resistance. However, transformed malignant cells can acquired resistance to ferroptosis through adaptative changes in their epigenome, genome, transcriptome, translatome or proteome. Multiple mechanisms, such as decreased coenzyme Q10 production mediated by the upregulation of apoptosis-inducing factor mitochondria-associated 2 (AIFM2/FSP1) and elevated expression of cytoprotective genes as a result of the activation of antioxidant transcription factor NFE2L2/NRF2 (nuclear factor erythroid 2-like 2), have been demonstrated to confer ferroptosis resistance. Therefore, unravelling the underlying mechanisms responsible for reduced sensitivity to ferroptosis inducers, such as erastin or RSL3, may pave the way for designing effective therapeutic regimens for PDAC patients.
Project description:Pancreatic ductal adenocarcinoma (PDAC) has one of the worst survival rates of all cancers. ANO1 (TMEM16A) is a recently identified Ca(2+)-activated Cl(-) channel (CaCC) that is upregulated in several tumors. Although ANO1 was subject to extensive studies in the recent years, its pathophysiological function has only been poorly understood. The aim of the present study is to establish the significance of ANO1 in PDAC behavior and demarcate its roles in PDAC from those of the volume-regulated anion channel (VRAC). We performed qPCR and Western blot measurements on different PDAC cell lines (Panc-1, Mia PaCa 2, Capan-1, AsPC-1, BxPC-3) and compared the results to those obtained in a human pancreatic ductal epithelium (HPDE) cell line. All cancer cell lines showed an upregulation of ANO1 on mRNA and protein levels. Whole-cell patch-clamp recordings identified large Ca(2+) and voltage-dependent Cl(-) currents in PDAC cells. Using siRNA knockdown of ANO1 and three ANO1 inhibitors (T16Ainh-A01, CaCCinh-A01, and NS3728), we found that ANO1 is the main constituent of CaCC current in PDAC cells. We further characterized these three inhibitors and found that they had unspecific effects on the free intracellular calcium concentration. Functional studies on PDAC behavior showed that surprisingly inhibition of ANO1 did not influence cellular proliferation. On the other hand, we found ANO1 channel to be pivotal in PDAC cell migration as assessed in wound healing experiments.
Project description:Introduction: PDAC is a lethal malignancy with a clear unmet need; almost all patients fail 1st, 2nd, and 3rd line multi-agent cytotoxic chemotherapy. The mammalian target of rapamycin (mTOR) has been identified as a key signaling node enhancing tumor survival and drug resistance in PDAC; hence, it is considered a promising therapeutic target. Areas covered: We comprehensively reviewed the evidence from preclinical and phase I and II clinical trials, based on the authors'clinical experience and a PubMed, Cochrane library, Embase, and Google Scholar search everolimus + pancreatic cancer. Expert opinion: Everolimus has not demonstrated efficacy in PDAC; however, an mTOR inhibitor in combination with stroma-targeted therapies may be a promising area to explore in clinical trials.
Project description:Treating pancreatic ductal adenocarcinoma (PDAC) remains a major hurdle in the field of oncology. Less than half of patients respond to frontline chemotherapy and the pancreatic tumor microenvironment limits the efficacy of immunotherapeutic approaches. Targeted therapies could serve as effective treatments to enhance the clinical response rate. One potential therapeutic target is survivin, a protein that is normally expressed during embryonic and fetal development and has a critical impact on cell cycle control and apoptosis. In adulthood, survivin is not present in most normal adult cells, but is significantly re-expressed in tumor tissues. In PDAC, elevated survivin expression is correlated with treatment resistance and lower patient survival, although the underlying mechanisms of survivin's action in this type of cancer is poorly understood. Using patient derived xenografts of PDAC and their corresponding primary pancreatic cancer lines (PPCL-46 and PPCL-LM1) possessing increased expression of survivin, we aimed to evaluate the therapeutic response of a novel survivin inhibitor, UFSHR, with respect to survivin expression and the tumorigenic characteristics of PDAC. Cell viability and apoptosis analyses revealed that repressing survivin expression by UFSHR or YM155, a well-known inhibitor of survivin, in PPCLs effectively reduces cell proliferation by inducing apoptosis. Tumor cell migration was also hindered following treatment with YM155 and UFSHR. In addition, both survivin inhibitors, particularly UFSHR, effectively reduced progression of PPCL-46 and PPCL-LM1 tumors, when compared to the untreated cohort. Overall, this study provides solid evidence to support the critical role of survivin in PDAC progression and proposes a novel survivin inhibitor UFSHR that can become an alternative strategy for this type of cancer.
Project description:(1) Background: Perineural invasion (PNI) is a common characteristic of pancreatic ductal adenocarcinoma (PDAC) and is present in most resection margins. We hypothesized that curative pancreatic tumor resection with long-term survival could only be achieved in PNI-negative patients. (2) Material and Methods: A retrospective investigation of PDAC patients who underwent curative-intended surgery during the period 2008 to 2019 was performed at our institution. (3) Results: We identified 571 of 660 (86.5%) resected patients with well-annotated reports and complete datasets. Of those, 531 patients (93%) exhibited tumors with perineural invasion (Pn1), while 40 (7%) were negative for PNI (Pn0). The majority of patients in the Pn1 group presented advanced tumor stage and positive lymph node infiltration. Patients in the Pn0 group showed an improved disease-free and long-term survival compared to the Pn1 group (p < 0.001). Subgroup analysis of all R0-resected patients indicated improved long-term survival and disease-free survival of R0 Pn0 patients when compared to R0 Pn1 patients (p < 0.001). (4) Conclusion: Our study confirmed that Pn0 improves the long-term survival of PDAC-resected cancer patients. Furthermore, PNI significantly challenges the long-term survival of formally curative (R0) resected patients. We provide new insights into the dynamics of PNI in pancreatic cancer patients which are needed to define subgroups of patients for risk stratification and multimodal treatment strategies.