Poor Survival Of Pancreatic Cancer Patients Research Articles

Abstract C018: Spatial profiling of tumor associated cells expressing endoplasmic reticulum stress proteins predicts poor outcomes in pancreatic cancer patients

Abstract The crosstalk between pancreatic cancer (PC) cells and cells of the tumor microenvironment (TME), such as immune cells and cancer associated fibroblasts (CAFs), has important implications for tumor progression. It is evident that the expression of endoplasmic reticulum (ER) stress proteins (e.g., BiP or CHOP) in tumor cells has survival implications for patients. For example, high BiP expression in tumor cells is correlated with poor survival in PC patients. However, the effect of these proteins in TME cells is currently unknown. We have employed quantitative multiplex immunofluorescence on a tumor microarray cohort of 259 treatment naive pancreatic cancer patient samples and 41 normal pancreas samples. We investigated the impact of expression of ER stress proteins BiP or CHOP in CAFS (α-SMA+), immune cells (CD45+), endothelial cells (CD31+) and tumor cells (PanCK+). HALO AI (Indica Labs) was used to conduct cell/tissue classifications and spatial proximity analysis. Notably, the proportion of CAFs and endothelial cells expressing BiP or CHOP was significantly (p<0.01-0.0001) increased in tumor sections compared to non-tumor sections. When considering the tumor sections, increased BiP expression in CAFs and endothelial cells was found to be correlated with vascular invasion (p=0.0388 and p=0.0318 respectively). Interestingly, there was also a positive correlation between the percent of total CAFs and the percent of BiP positive cells (p=0.0037, r=0.293) or CHOP positive cells (p=0.0001, r=0.235), suggesting that ER stress could be associated with activation of CAFs. Spatial analysis was next utilized to explore the distribution of cells expressing BiP or CHOP within the TME. Remarkably, when examining the average distance in a 500 μm radius, our findings showed that immune cells expressing BiP or CHOP were located significantly (p<0.0001) closer to tumor cells compared to non-expressing immune cells. Interestingly, increased distance of CHOP expressing immune cells to tumor cells was negatively correlated (p=0.037, r=-0.137) with tumor size. We next examined these cells within a 20 μm radius of tumor cells, as it represents a physiologically feasible distance for direct cell-cell contact. Increased numbers of CHOP CD45 cells within the 20 μm radius was correlated with poorer overall survival (p=0.0062) and event free survival (p=0.046). Similarly, in CAFS, BiP expressing cells were found on average closer to tumor cells (p<0.0001), although this was not associated with patient survival. The observed correlation between elevated ER stress in TME cells with adverse patient outcomes indicates the importance of BiP or CHOP as potential therapeutic targets. Furthermore, the spatial analysis results provide insights into the organization of TME cells, shedding light on the significance of ER stress in the TME. These findings contribute to our understanding of the complex interplay between ER stress, tumor biology, and patient outcomes in PC. Citation Format: Georgia M. Porter, Murray Norris, Minoti Apte, Angelica Merlot. Spatial profiling of tumor associated cells expressing endoplasmic reticulum stress proteins predicts poor outcomes in pancreatic cancer patients [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C018.

Adipose Tissue Wasting as a Determinant of Pancreatic Cancer-Related Cachexia.

Simple SummaryPancreatic cancer (PC) is one of the deadliest cancers in the US. The poor prognosis of PC is related to diagnostic delay and the presence of unintended weight loss (cachexia) that commonly presents in PC patients even before diagnosis. However, the current understanding of how PC mediates cachexia is limited, and there are few treatments clinically available for cachexia. Based on the current literature, we demonstrate that PC-related cachexia primarily results from the wasting of adipose tissue, once thought to be merely a storage depot but now appreciated as an instrumental metabolic organ in the body. In addition, poor survival in PC patients was found to be associated with adipose tissue loss at diagnosis and during treatment. Therefore, identifying potential mediators and molecular mechanisms underlying adipose tissue loss would promise to pave the way for the development of effective interventions for PC-related cachexiaPancreatic cancer (PC) is the third leading cause of cancer-related death in the US, and its 5-year survival rate is approximately 10%. The low survival rates largely stem from diagnostic delay and the presence of significant adipose tissue and muscle wasting, commonly referred to as cachexia. Cachexia is present in nearly 80% of PC patients and is a key cause of poor response to treatment and about 20% of death in PC patients. However, there are few clinical interventions proven to be effective against PC-related cachexia. Different cancer types feature distinct secretome profiles and functional characteristics which would lead to cachexia development differently. Therefore, here we discuss affected tissues and potential mechanisms leading to cachexia in PC. We postulate that the most affected tissue during the development of PC-related cachexia is adipose tissue, historically and still thought to be just an inert repository for excess energy in relation to cancer-related cachexia. Adipose tissue loss is considerably greater than muscle loss in quantity and shows a correlation with poor survival in PC patients. Moreover, we suggest that PC mediates adipose atrophy by accelerating adipocyte lipid turnover and fibroblast infiltration.

Hypoxic Tumor-Derived Exosomal Long Noncoding RNA UCA1 Promotes Angiogenesis via miR-96-5p/AMOTL2 in Pancreatic Cancer

The hypoxic microenvironment, an important feature of solid tumors, promotes tumor cells to release exosomes and enhances tumor angiogenesis. However, the detailed functions of hypoxic exosomes and the mechanisms underlying their effects in pancreatic cancer (PC) remain mysterious. Here, we observed that hypoxic exosomes derived from PC cells promoted cell migration and tube formation of human umbilical vein endothelial cells (HUVECs). The long noncoding RNA (lncRNA) UCA1, a key factor, was highly expressed in exosomes derived from hypoxic PC cells and could be transferred to HUVECs through the exosomes. In addition, the expression levels of UCA1 in exosomes derived from PC patients’ serum were higher than in healthy controls and were associated with poor survival of PC patients. Moreover, hypoxic exosomal UCA1 could promote angiogenesis and tumor growth both in vitro and in vivo. With respect to the functional mechanism, UCA1 acted as a sponge of microRNA (miR)-96-5p, relieving the repressive effects of miR-96-5p on the expression of its target gene AMOTL2. Collectively, these results indicate that hypoxic exosomal UCA1 could promote angiogenesis and tumor growth through the miR-96-5p/AMOTL2/ERK1/2 axis and therefore, serve as a novel target for PC treatment.

CD147 promotes DNA damage response and gemcitabine resistance via targeting ATM/ATR/p53 and affects prognosis in pancreatic cancer

The acquisition of chemoresistance is a major clinical challenge for pancreatic cancer (PC) treatment. Chemoresistance is largely attributed to aberrant DNA damage repair. However, the underlying mechanisms of chemoresistance in pancreatic cancer remain unclear. Here, we showed that CD147 was strongly correlated to DNA damage response (DDR) indices and poor prognosis in pancreatic ductal adenocarcinoma (PDAC) patients. CD147 knockdown or monoclonal antibodies improved the killing effects of gemcitabine in gemcitabine resistant cells, exhibiting reduced activation of ATM/p53.Moreover, we found the interaction of CD147 with ATM, ATR and p53, which was augmented in gemcitabine resistant cells. High CD147/p-ATM/p-ATR/p-p53 cytoplasmic expression associated with poor survival of PC patients. Our studies thus identify CD147 as a critical player in DDR programing that affects gemcitabine therapeutic outcomes of pancreatic cancer patients.

DRP1 upregulation promotes pancreatic cancer growth and metastasis through increased aerobic glycolysis.

Mitochondrial shape is dynamically changed by fusion and fission processes in cells, and dysfunction of this process has become one of the emerging hallmarks of cancer. However, the expression patterns and biological effects of mitochondrial fission and fusion proteins in pancreatic cancer (PC) are still unclear. The expressions of mitochondrial fission and fusion proteins were first evaluated by quantitative reverse transcription polymerase chain reaction and western blot analysis in both PC cell lines and tissue samples. In addition, the biologic functions of the differentially expressed proteins in PC cell growth and metastasis both in vitro and in vivo and their potential underlying mechanisms were systematically explored. We first found that DRP1 was substantially upregulated in PC cell lines and tissue samples mainly due to the downregulation of miR-29a, which contributed to the poor survival of PC patients. DRP1 promoted the growth and metastasis of PC cells both in vitro and in vivo by inducing G1-S cell cycle transition and matrix metalloproteinase 2 secretion. Mechanistic investigations revealed that increased DRP1 upregulation-mediated mitochondrial fission and subsequently enhanced aerobic glycolysis were involved in the promotion of growth and metastasis by DRP1 in PC cells. Our findings demonstrate that mitochondrial fusion protein DRP1 plays a critical oncogenic role in PC cells by enhancing aerobic glycolysis, which could serve as a novel therapeutic target for PC treatment.

USP39, a direct target of microRNA-133a, promotes progression of pancreatic cancer via the AKT pathway

Ubiquitin specific protease 39 (USP39) is one of the deubiquitinating enzymes without ubiquitin protease activity, which has been implicated in the progression of several cancers. However, the role of USP39 in pancreatic cancer (PC) is largely unknown. In present study, we found that USP39 expression was elevated in PC tissues than adjacent non-tumor tissues. Importantly, we demonstrated that overexpression of USP39 is closely correlated with tumor progression and poor survival in PC patients. Furthermore, high USP39 expression was observed in PC cell lines and ectopic expression of USP39 significantly enhanced in vitro cell proliferation and promoted in vivo tumor growth, whereas silencing USP39 suppressed growth of PC cells. Besides, our experimental data revealed that knockdown of USP39 induced cell apoptosis through inhibition of AKT signaling pathway in PC cells. Moreover, USP39 was a direct target of miR-133a, a microRNA that has been reported to be involved in progression of PC. Taken together, our data provide a novel PC regulatory axis that is miR-133a/USP39, the dysfunction of which drives diverse aspects of the progression of PC.

Long non-coding RNA NEAT1 facilitates pancreatic cancer progression through negative modulation of miR-506-3p

Recently, long non-coding RNAs (lncRNAs) have been shown to have critical regulatory roles in tumourigenesis. Increasing evidence has suggested that lncRNA NEAT1 has been implicated in various types of human cancer. However, the potential biological roles and regulatory mechanisms of NEAT1 in pancreatic cancer (PC) remains unclear. Here, we found that the expression level of NEAT1 was higher in PC tissues compared to the corresponding non-tumor tissues. Besides, our findings indicate that high NEAT1 expression level is closely correlated with tumor progression and poor survival in PC patients. Furthermore, we also found that knockdown of NEAT1 remarkably suppressed cell proliferation by inducing cell cycle arrest and apoptosis promotion in PC cells. Moreover, bioinformatics analysis and luciferase reporter assay revealed that NEAT1 directly bound to the miR-506-3p, which has been reported to act as a tumor suppressor in diverse cancers. Additionally, our results confirmed that the tumor-promoting effects of NEAT1 in PC cells is at least partly through negative modulation of miR-506-3p. Overall, our results suggested that NEAT1 functions as an oncogenic lncRNA in PC, which could be a novel diagnostic and therapeutic target for PC.

Up-Regulation of MBD1 Promotes Pancreatic Cancer Cell Epithelial-Mesenchymal Transition and Invasion by Epigenetic Down-Regulation of E-Cadherin

Methyl-CpG binding domain protein 1 (MBD1) has been implicated in transcriptional regulation, heterochromatin formation, genomic stability, cell-cycle progression and development. It is also predicted that MBD1 might be involved in tumor development and progression. However, whether and how MBD1 is involved in tumorigenesis, especially in pancreatic cancer (PC), is currently unknown. We found that MBD1 was significantly up-regulated in PC tissues compared with the surrounding normal tissues according to RT-PCR data. Tissue microarray (TMA) based immunohistochemical study from 58 surgically resected PC specimens indicated that higher MBD1 expression correlated with lymph node metastasis and poor survival in PC patients. Gain- and loss-of-function studies in vitro validated MBD1 as a potent oncogene promoting PC cell invasion as well as epithelial-mesenchymal transition (EMT). Mechanistically, MBD1 is associated with Twist and NAD-dependent deacetylase sirtuin-1 (SIRT1), thereby forming the Twist-MBD1-SIRT1 complex on the CDH1 promoter, which resulted in reduced E-cadherin transcription activity and increased cell EMT ability. Significantly, targeting MBD1 reversed the EMT phenotype of PC and restored sensitivity to chemotherapy. Taken together, the results of our study revealed a novel function of MBD1 in PC invasion and metastasis by providing a molecular mechanism underlying MBD1-promoted EMT. Thus MBD1 may serve as a potential therapeutic target for PC.