Roles of EGFR and KRAS and their downstream signaling pathways in pancreatic cancer and pancreatic cancer stem cells

Unraveling the interplay: exploring signaling pathways in pancreatic cancer in the context of pancreatic embryogenesis

Pancreatic cancer continues to be a deadly disease because of its delayed diagnosis and aggressive tumor biology. Oncogenes and risk factors are being reported to influence the signaling pathways involved in pancreatic embryogenesis leading to pancreatic cancer genesis. Although studies using rodent models have yielded insightful information, the scarcity of human pancreatic tissue has made it difficult to comprehend how the human pancreas develops. Transcription factors like IPF1/PDX1, HLXB9, PBX1, MEIS, Islet-1, and signaling pathways, including Hedgehog, TGF-β, and Notch, are directing pancreatic organogenesis. Any derangements in the above pathways may lead to pancreatic cancer. TP53: and CDKN2A are tumor suppressor genes, and the mutations in TP53 and somatic loss of CDKN2A are the drivers of pancreatic cancer. This review clarifies the complex signaling mechanism involved in pancreatic cancer, the same signaling pathways in pancreas development, the current therapeutic approach targeting signaling molecules, and the mechanism of action of risk factors in promoting pancreatic cancer.

Integrative transcriptome analysis reveals the molecular events underlying impaired T-cell responses in EGFR-mutant lung cancer

EGFR mutations are critical oncogenic drivers in lung adenocarcinoma (LUAD). However, the mechanisms by which they impact the tumor microenvironment (TME) and tumor immunity are unclear. Furthermore, the reasons underlying the poor response of EGFR-mutant (EGFR-MU) LUADs to immunotherapy with PD-1/PD-L1 inhibitors are unknown. Utilizing single-cell RNA (sc-RNA) and bulk RNA sequencing datasets, we conducted high-dimensional weighted gene coexpression network analysis to identify key genes and immune-related pathways contributing to the immunosuppressive TME. EGFR-MU cancer cells downregulated MHC class I genes to evade CD8+ cytotoxic T cells, expressed substantial levels of MHC class II molecules, and engaged with CD4+ regulatory T cells (Tregs). EGFR-MU tumors may recruit Tregs primarily through the CCL17/CCL22/CCR4 axis, leading to a Treg-enriched TME. High levels of MHC class II-positive cancer-associated fibroblasts and tumor endothelial cells were found within EGFR-MU tumors. Owing to the absence of costimulatory factors, they may inhibit rather than activate the tumor antigen-specific CD4+ T-cell response, contributing further to immune suppression. Multiplex immunohistochemistry analyses in a LUAD cohort confirmed increased expression of MHC class II molecules in cancer cells and fibroblasts in EGFR-MU tumors. Our research elucidates the highly immunosuppressive TME in EGFR-MU LUAD and suggests potential targets for effective immunotherapy.

Advancements and perspectives of RBX2 as a molecular hallmark in cancer

Cancer is a challenging issue for human health. One of the key methods to address this issue is by comprehending the molecular causes of tumors and creating medications that target those causes. RBX2 (RING box protein 2), also known as ROC2 (Regulator of Cullins 2), RNF7 (RING Finger Protein 7), or SAG (Sensitive to Apoptosis Gene) is a key component of the Cullin-RING-type E3 ubiquitin ligases (CRLs) and overexpressed in various human cancers. RBX2 is a potential drug target, the expression of which correlates with tumor staging, grading, and prognosis analysis. Through a synergistically biological interaction with Kras mutation in preclinical models, RBX2 accelerated the progression of skin cancer, pancreatic cancer, and lung cancer. In accordance, the aberrant expression of RBX2 will lead to dysregulation of many signaling pathways, which is crucial for tumor initiation and growth. However, the impact of RBX2 on tumors also intriguingly demonstrates a spatial reliance manner. In this review, we summarized the current understanding of RBX2 in multiple cancer types and suggested a significant potential of RBX2 as a therapeutic target.

Deoxyribonucleic acid methylation driven aberrations in pancreatic cancer-related pathways

Pancreatic cancer (PanCa) presents a catastrophic disease with poor overall survival at advanced stages, with immediate requirement of new and effective treatment options. Besides genetic mutations, epigenetic dysregulation of signaling pathway-associated enriched genes are considered as novel therapeutic target. Mechanisms beneath the deoxyribonucleic acid methylation and its utility in developing of epi-drugs in PanCa are under trails. Combinations of epigenetic medicines with conventional cytotoxic treatments or targeted therapy are promising options to improving the dismal response and survival rate of PanCa patients. Recent studies have identified potentially valid pathways that support the prediction that future PanCa clinical trials will include vigorous testing of epigenomic therapies. Epigenetics thus promises to generate a significant amount of new knowledge of biological and medical importance. Our review could identify various components of epigenetic mechanisms known to be involved in the initiation and development of pancreatic ductal adenocarcinoma and related precancerous lesions, and novel pharmacological strategies that target these components could potentially lead to breakthroughs. We aim to highlight the possibilities that exist and the potential therapeutic interventions.

Molecular Mechanisms of Tumor Cell Stemness Modulation during Formation of Spheroids

Cancer stem cells (CSCs), their properties and interaction with microenvironment are of interest in modern medicine and biology. There are many studies on the emergence of CSCs and their involvement in tumor pathogenesis. The most important property inherent to CSCs is their stemness. Stemness combines ability of the cell to maintain its pluripotency, give rise to differentiated cells, and interact with environment to maintain a balance between dormancy, proliferation, and regeneration. While adult stem cells exhibit these properties by participating in tissue homeostasis, CSCs behave as their malignant equivalents. High tumor resistance to therapy, ability to differentiate, activate angiogenesis and metastasis arise precisely due to the stemness of CSCs. These cells can be used as a target for therapy of different types of cancer. Laboratory models are needed to study cancer biology and find new therapeutic strategies. A promising direction is three-dimensional tumor models or spheroids. Such models exhibit properties resembling stemness in a natural tumor. By modifying spheroids, it becomes possible to investigate the effect of therapy on CSCs, thus contributing to the development of anti-tumor drug test systems. The review examines the niche of CSCs, the possibility of their study using three-dimensional spheroids, and existing markers for assessing stemness of CSCs.

Plumbagin binds to epidermal growth factor receptor and mitigate the effects of epidermal growth factor micro-environment in PANC-1 cells

A sustained increase in the mortality of pancreatic cancer (PC) and sudden metastasis-related mortality is a cause for concern. Aberrant expression of epidermal growth factor (EGF) receptor (EGFR) is noted in several cases of PC metastasis. The present study is aimed at analyzing the expression of EGFR in PC and its relevance to the progression of PC. Despite the number of studies that have shown the benefits of plumbagin on PC cells, its role on cancer stem cells remains largely unknown. To this end, the study used an EGF micro-environment to make cancer stem cells in vitro and ascertained the role of plumbagin in mitigating the actions of EGF. The kaplan-meier (KM) plot indicated reduced overall survival (OS) analysis in PC patients with high EGFR than low EGFR expression. Plumbagin pre-treatment significantly prevented EGF-induced survival, epithelial-to-mesenchymal transition (EMT), clonogenesis, migration, matrix metalloproteinase -2 (MMP-2) gene expression and its secretion, and matrix protein hyaluron production in PANC-1 cells. The computational studies indicate the greater affinity of plumbagin with different domains of EGFR than gefitinib. Several hallmarks of resistance and migration due to EGF are effectively attenuated by plumbagin. Collectively, these results warrant investigating the actions of plumbagin in a pre-clinical study to substantiate these findings.

Role of long non-coding RNAs in pancreatic cancer pathogenesis and treatment resistance- A review

Pancreatic cancer (PC) is one of the deadliest cancers associated with poor prognosis. The lack of reliable means of early cancer detection contributes to this disease's dismal prognosis. Long non-coding RNAs (LncRNAs) are protein-free RNAs produced by genome transcription; they play critical roles in gene expression regulation, epigenetic modification, cell proliferation, differentiation, and reproduction. Recent research has shown that lncRNAs play important regulatory roles in PC behaviors, in addition to their recently found functions. Several in-depth investigations have shown that lncRNAs are strongly linked to PC development and progression. Here, we discuss how lncRNAs, which are often overlooked, play many roles as regulators in the molecular mechanism underlying PC. This review also discusses the involved LncRNAs in PC pathogenesis and treatment resistance.

Clinical and Molecular Attributes and Evaluation of Pancreatic Cystic Neoplasm

Intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) are all considered "Pancreatic cystic neoplasms (PCNs)" and show a varying risk of developing into pancreatic ductal adenocarcinoma (PDAC). These lesions display different molecular characteristics, mutations, and clinical manifestations. A lack of detailed understanding of PCN subtype characteristics and their molecular mechanisms limits the development of efficient diagnostic tools and therapeutic strategies for these lesions. Proper in vivo mouse models that mimic human PCNs are also needed to study the molecular mechanisms and for therapeutic testing. A comprehensive understanding of the current status of PCN biology, mechanisms, current diagnostic methods, and therapies will help in the early detection and proper management of patients with these lesions and PDAC. This review aims to describe all these aspects of PCNs, specifically IPMNs, by describing the future perspectives.

Glycogen Synthase Kinase 3β: A True Foe in Pancreatic Cancer

Glycogen synthase kinase 3 beta (GSK-3β) is a serine/threonine protein kinase involved in multiple normal and pathological cell functions, including cell signalling and metabolism. GSK-3β is highly expressed in the onset and progression of multiple cancers with strong involvement in the regulation of proliferation, apoptosis, and chemoresistance. Multiple studies showed pro- and anti-cancer roles of GSK-3β creating confusion about the benefit of targeting GSK-3β for treating cancer. In this mini-review, we focus on the role of GSK-3β in pancreatic cancer. We demonstrate that the proposed anti-cancer roles of GSK-3β are not relevant to pancreatic cancer, and we argue why GSK-3β is, indeed, a very promising therapeutic target in pancreatic cancer.

The Role of Genomics and Proteomics in Lung Cancer Early Detection and Treatment

Lung cancer is the leading cause of cancer-related death worldwide, with non-small-cell lung cancer (NSCLC) being the primary type. Unfortunately, it is often diagnosed at advanced stages, when therapy leaves patients with a dismal prognosis. Despite the advances in genomics and proteomics in the past decade, leading to progress in developing tools for early diagnosis, targeted therapies have shown promising results; however, the 5-year survival of NSCLC patients is only about 15%. Low-dose computed tomography or chest X-ray are the main types of screening tools. Lung cancer patients without specific, actionable mutations are currently treated with conventional therapies, such as platinum-based chemotherapy; however, resistances and relapses often occur in these patients. More noninvasive, inexpensive, and safer diagnostic methods based on novel biomarkers for NSCLC are of paramount importance. In the current review, we summarize genomic and proteomic biomarkers utilized for the early detection and treatment of NSCLC. We further discuss future opportunities to improve biomarkers for early detection and the effective treatment of NSCLC.

Decrypting a path based approach for identifying the interplay between PI3K and GSK3 signaling cascade from the perspective of cancer

Cancer is one of those leading diseases worldwide, which takes millions of lives every year. Researchers are continuously looking for specific approaches to eradicate the deadly disease, ensuring minimal adverse effects along with more therapeutic significance. Targeting of different aberrantly regulated signaling pathways, involved in cancer, is surely one of the revolutionary chemotherapeutic approach. In this instance, GSK3 and PI3K signaling cascades are considered as important role player for both the oncogenic activation and inactivation which further leads to cancer proliferation and metastasis. In this review, we have discussed the potential role of GSK3 and PI3K signaling in cancer, and we further established the crosstalk between PI3K and GSK3 signaling, through showcasing their cross activation, cross inhibition and convergence pathways in association with cancer. We also exhibited the effect of GSK3 on the efficacy of PI3K inhibitors to overcome the drug resistance and preventing the cell proliferation, metastasis in a combinatorial way with GSK3 inhibitors for a better treatment strategy in clinical settings.

Cancer Stem Cells: From an Insight into the Basics to Recent Advances and Therapeutic Targeting

Cancer is characterized by an abnormal growth of the cells in an uncontrolled manner. These cells have the potential to invade and can eventually turn into malignancy, leading to highly fatal forms of tumor. Small subpopulations of cancer cells that are long-lived with the potential of excessive self-renewal and tumor formation are called cancer stem cells (CSCs) or cancer-initiating cells or tumor stem cells. CSCs can be found in tissues, such as breast, brain, lung, liver, ovary, and testis; however, their origin is still a matter of debate. These cells can differentiate and possess self-renewal capacity maintained by numerous intracellular signal transduction pathways, such as the Wnt/β-catenin signaling, Notch signaling, transforming growth factor-β signaling, and Hedgehog signaling. They can also contribute to numerous malignancies and are an important reason for tumor recurrence and metastasis because they are resistant to the known therapeutic strategies that mainly target the bulk of the tumor cells. This review contains collected and compiled information after analyzing published works of the last three decades. The goal was to gather information of recent breakthroughs related to CSCs, strategies to target CSCs' niche (e.g., nanotechnology with tumor biology), and their signaling pathways for cancer therapy. Moreover, the role of metformin, an antidiabetic drug, acting as a chemotherapeutic agent on CSCs by inhibiting cellular transformation and its selective killing is also addressed.

Sesquiterpene Lactones as Promising Candidates for Cancer Therapy: Focus on Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease which confers to patients a poor prognosis at short term. PDAC is the fourth leading cause of death among cancers in the Western world. The rate of new cases of pancreatic cancer (incidence) is 10 per 100,000 but present a 5-year survival of less than 10%, highlighting the poor prognosis of this pathology. Furthermore, 90% of advanced PDAC tumor present KRAS mutations impacting in several oncogenic signaling pathways, many of them associated with cell proliferation and tumor progression. Different combinations of chemotherapeutic agents have been tested over the years without an improvement of significance in its treatment. PDAC remains as one the more challenging biomedical topics thus far. The lack of a proper early diagnosis, the notable mortality statistics and the poor outcome with the available therapies urge the entire scientific community to find novel approaches against PDAC with real improvements in patients' survival and life quality. Natural compounds have played an important role in the process of discovery and development of new drugs. Among them, terpenoids, such as sesquiterpene lactones, stand out due to their biological activities and pharmacological potential as antitumor agents. In this review, we will describe the sesquiterpene lactones with in vitro and in vivo activity against pancreatic tumor cells. We will also discuss the mechanism of action of the compounds as well as the signaling pathways associated with their activity.

Overcoming Immunotherapeutic Resistance in PDAC: SIRPα-CD47 blockade

A daily increase in the number of new cases of pancreatic ductal adenocarcinoma remains an issue of contention in cancer research. The data revealed that a global cumulated case of about 500, 000 have been reported. This has made PDAC the fourteenth most occurring tumor case in cancer research. Furthermore, PDAC is responsible for about 466,003 deaths annually, representing the seventh prevalent type of cancer mortality. PDAC has no salient symptoms in its early stages. This has exasperated several attempts to produce a perfect therapeutic agent against PDAC. Recently, immunotherapeutic research has shifted focus to the blockade of checkpoint proteins in the management and of some cancers. Investigations have centrally focused on developing therapeutic agents that could at least to a significant extent block the SIRPα-CD47 signaling cascade (a cascade which prevent phagocytosis of tumors by dendritic cells, via the deactivation of innate immunity and subsequently resulting in tumor regression) with minimal side effects. The concept on the blockade of this interaction as a possible mechanism for inhibiting the progression of PDAC is currently being debated. This review examined the structure--function activity of SIRPα-CD47 interaction while discussing in detail the mechanism of tumor resistance in PDAC. Further, this review details how the blockade of SIRPα-CD47 interaction serve as a therapeutic option in the management of PDAC.

Wild type and gain of function mutant TP53 can regulate the sensitivity of pancreatic cancer cells to chemotherapeutic drugs, EGFR/Ras/Raf/MEK, and PI3K/mTORC1/GSK-3 pathway inhibitors, nutraceuticals and alter metabolic properties

TP53 is a master regulator of many signaling and apoptotic pathways involved in: aging, cell cycle progression, gene regulation, growth, apoptosis, cellular senescence, DNA repair, drug resistance, malignant transformation, metastasis, and metabolism. Most pancreatic cancers are classified as pancreatic ductal adenocarcinomas (PDAC). The tumor suppressor gene TP53 is mutated frequently (50-75%) in PDAC. Different types of TP53 mutations have been observed including gain of function (GOF) point mutations and various deletions of the TP53 gene resulting in lack of the protein expression. Most PDACs have point mutations at the KRAS gene which result in constitutive activation of KRas and multiple downstream signaling pathways. It has been difficult to develop specific KRas inhibitors and/or methods that result in recovery of functional TP53 activity. To further elucidate the roles of TP53 in drug-resistance of pancreatic cancer cells, we introduced wild-type (WT) TP53 or a control vector into two different PDAC cell lines. Introduction of WT-TP53 increased the sensitivity of the cells to multiple chemotherapeutic drugs, signal transduction inhibitors, drugs and nutraceuticals and influenced key metabolic properties of the cells. Therefore, TP53 is a key molecule which is critical in drug sensitivity and metabolism of PDAC.

Intrinsic and Extrinsic Factors Impacting Cancer Stemness and Tumor Progression

Tumor heterogeneity represents an important limitation to the development of effective cancer therapies. The presence of cancer stem cells (CSCs) and their differentiation hierarchies contribute to cancer complexity and confer tumors the ability to grow, resist treatment, survive unfavorable conditions, and invade neighboring and distant tissues. A large body of research is currently focusing on understanding the properties of CSCs, including their cellular and molecular origin, as well as their biological behavior in different tumor types. In turn, this knowledge informs strategies for targeting these tumor initiating cells and related cancer stemness. Cancer stemness is modulated by the tumor microenvironment, which influences CSC function and survival. Several advanced in vitro models are currently being developed to study cancer stemness in order to advance new knowledge of the key molecular pathways involved in CSC self-renewal and dormancy, as well as to mimic the complexity of patients' tumors in pre-clinical drug testing. In this review, we discuss CSCs and the modulation of cancer stemness by the tumor microenvironment, stemness factors and signaling pathways. In addition, we introduce current models that allow the study of CSCs for the development of new targeted therapies.

E-cigarette and food flavoring diacetyl alters airway cell morphology, inflammatory and antiviral response, and susceptibility to SARS-CoV-2

Diacetyl (DA) is an α-diketone that is used to flavor microwave popcorn, coffee, and e-cigarettes. Occupational exposure to high levels of DA causes impaired lung function and obstructive airway disease. Additionally, lower levels of DA exposure dampen host defenses in vitro. Understanding DA’s impact on lung epithelium is important for delineating exposure risk on lung health. In this study, we assessed the impact of DA on normal human bronchial epithelial cell (NHBEC) morphology, transcriptional profiles, and susceptibility to SARS-CoV-2 infection. Transcriptomic analysis demonstrated cilia dysregulation, an increase in hypoxia and sterile inflammation associated pathways, and decreased expression of interferon-stimulated genes after DA exposure. Additionally, DA exposure resulted in cilia loss and increased hyaluronan production. After SARS-CoV-2 infection, both genomic and subgenomic SARS-CoV-2 RNA were increased in DA vapor- compared to vehicle-exposed NHBECs. This work suggests that transcriptomic and physiologic changes induced by DA vapor exposure damage cilia and increase host susceptibility to SARS-CoV-2.

Moving Towards Dawn: KRas Signaling and Treatment in Pancreatic Ductal Adenocarcinoma

"Pancreatic ductal adenocarcinoma (PDAC)" is robust, nearly clueless, and all-around deadly among all tumors. Below 10 %, the general 5-year endurance period has remained adamantly unaltered in the last 30 years, regardless of enormous clinical and therapeutic endeavors. The yearly number of deaths is more than the number of recently analyzed cases. Not a classic one, but "Carbohydrate Antigen CA19- 9" remains the prevailing tool for diagnosis. MicroRNAs and non-invasive techniques are now incorporated for the effective prognosis of PDAC than just CA19-9. Mutated "Rat sarcoma virus Ras" conformation "V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog KRas" is 95 % accountable for PDAC, and its active (GTP-bound) formation activates signaling cascade comprising "Rapidly accelerated fibrosarcoma Raf"/"Mitogen-activated protein kinase MEK"/ "Extracellular signal-regulated kinase ERK" with "Phosphoinositide 3-kinase PI3K"/ "protein kinase B Akt"/ "mammalian target of rapamycin mTOR" pathways. KRas has acquired the label of 'undruggable' since the crosstalk in the nexus of pathways compensates for Raf and PI3K signaling cascade blocking. It is arduous to totally regulate KRascoordinated PDAC with traditional medicaments like "gemcitabine GEM" plus nabpaclitaxel/ FOLFIRINOX. For long-haul accomplishments aiming at KRas, future endeavors should be directed to combinatorial methodologies to adequately block KRas pathways at different standpoints. Currently they are contributing to healing PDAC. In this review article, we outline the function of KRas in carcinogenesis in PDAC, its signaling cascade, former techniques utilized in hindering Kras, current and future possibilities for targeting Kras.

Phospho-Aspirin (MDC-22) inhibits pancreatic cancer growth in patient-derived tumor xenografts and KPC mice by targeting EGFR: Enhanced efficacy in combination with irinotecan

Novel therapeutic strategies are needed in the fight against pancreatic cancer. We have previously documented the chemopreventive effect of MDC-22 in preclinical models of pancreatic cancer. In the present work, we examined the therapeutic effects of MDC-22 in patient-derived tumor xenografts (PDTXs) and in LSL-Kras^G12D/+, LSL-Trp53^R172H/+, Pdx1-Cre (KPC) genetically engineered mice, two complementary and clinically relevant animal models of pancreatic cancer. In addition, we evaluated whether MDC-22 could synergize with current chemotherapeutic drugs used in the clinic. MDC-22 reduced the growth of various human pancreatic cancer cell lines in a concentration-dependent manner. In vivo, MDC-22 strongly reduced patient-derived pancreatic tumor xenograft growth by 50%, and extended survival of LSL-Kras^G12D/+; LSL-Trp53^R172H/+; Pdx1-Cre (KPC) mice by over a month (5.3 months versus 7.0 months). In both models, MDC-22 inhibited EGFR activation and its downstream signals, including ERK and FAK phosphorylation. In human pancreatic cancer cell lines, MDC-22 enhanced the growth inhibitory effect of irinotecan, and to a lesser degree those of gemcitabine and nab-paclitaxel. Normal human pancreatic epithelial cells were more resistant to the cytotoxic effects of, both, MDC-22 alone or in combination with irinotecan, indicating selectivity. Furthermore, MDC-22 enhanced irinotecan's effect on cell migration, in part, by inhibiting EGFR/FAK signaling. Collectively, our results indicate that MDC-22 is an effective anticancer drug in preclinical models of pancreatic cancer, and suggest that MDC-22 plus irinotecan as drug combination strategy for pancreatic cancer treatment, which warrants further evaluation.

Mechanisms of Cancer Cell Death: Therapeutic Implications for Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a type of cancer that is strongly associated with poor prognosis and short median survival times. In stark contrast to the progress seen in other cancer types in recent decades, discoveries of new treatments in PDAC have been few and far between and there has been little improvement in overall survival (OS). The difficulty in treating this disease is multifactorial, contributed to by late presentation, difficult access to primary tumour sites, an 'immunologically cold' phenotype, and a strong tendency of recurrence likely driven by cancer stem cell (CSC) populations. Furthermore, apparently contrasting roles of tumour components (such as fibrotic stroma) and intracellular pathways (such as autophagy and TGFβ) have made it difficult to distinguish beneficial from detrimental drug targets. Despite this, progress has been made in the field, including the determination of mFOLFIRINOX as the standard-of-care adjuvant therapy and the discovery of KRASG12C mutant inhibitors. Moreover, new research, as outlined in this review, has highlighted promising new approaches including the targeting of the tumour microenvironment, enhancement of immunotherapies, epigenetic modulation, and destruction of CSCs.

The Oncogenic Signaling Disruptor, NDRG1: Molecular and Cellular Mechanisms of Activity

NDRG1 is an oncogenic signaling disruptor that plays a key role in multiple cancers, including aggressive pancreatic tumors. Recent studies have indicated a role for NDRG1 in the inhibition of multiple tyrosine kinases, including EGFR, c-Met, HER2 and HER3, etc. The mechanism of activity of NDRG1 remains unclear, but to impart some of its functions, NDRG1 binds directly to key effector molecules that play roles in tumor suppression, e.g., MIG6. More recent studies indicate that NDRG1s-inducing drugs, such as novel di-2-pyridylketone thiosemicarbazones, not only inhibit tumor growth and metastasis but also fibrous desmoplasia, which leads to chemotherapeutic resistance. The Casitas B-lineage lymphoma (c-Cbl) protein may be regulated by NDRG1, and is a crucial E3 ligase that regulates various protein tyrosine and receptor tyrosine kinases, primarily via ubiquitination. The c-Cbl protein can act as a tumor suppressor by promoting the degradation of receptor tyrosine kinases. In contrast, c-Cbl can also promote tumor development by acting as a docking protein to mediate the oncogenic c-Met/Crk/JNK and PI3K/AKT pathways. This review hypothesizes that NDRG1 could inhibit the oncogenic function of c-Cbl, which may be another mechanism of its tumor-suppressive effects.

Regulatory mechanisms of heme regulatory protein BACH1: a potential therapeutic target for cancer

A limited number of overexpressed transcription factors are associated with cancer progression in many types of cancer. BTB and CNC homology 1 (BACH1) is the first mammalian heme-binding transcription factor that belongs to the basic region leucine zipper (bZIP) family and a member of CNC (cap 'n' collar). It forms heterodimers with the small musculoaponeurotic fibrosarcoma (MAF) proteins and stimulates or suppresses the expression of target genes under a very low intracellular heme concentration. It possesses a significant regulatory role in heme homeostasis, oxidative stress, cell cycle, apoptosis, angiogenesis, and cancer metastasis progression. This review discusses the current knowledge about how BACH1 regulates cancer metastasis in various types of cancer and other carcinogenic associated factors such as oxidative stress, cell cycle regulation, apoptosis, and angiogenesis. Overall, from the reported studies and outcomes, it could be realized that BACH1 is a potential pharmacological target for discovering new therapeutic anticancer drugs.

Cell-free DNA TAPS provides multimodal information for early cancer detection

Multimodal, genome-wide characterization of epigenetic and genetic information in circulating cell-free DNA (cfDNA) could enable more sensitive early cancer detection, but it is technologically challenging. Recently, we developed TET-assisted pyridine borane sequencing (TAPS), which is a mild, bisulfite-free method for base-resolution direct DNA methylation sequencing. Here, we optimized TAPS for cfDNA (cfTAPS) to provide high-quality and high-depth whole-genome cell-free methylomes. We applied cfTAPS to 85 cfDNA samples from patients with hepatocellular carcinoma (HCC) or pancreatic ductal adenocarcinoma (PDAC) and noncancer controls. From only 10 ng of cfDNA (1 to 3 ml of plasma), we generated the most comprehensive cfDNA methylome to date. We demonstrated that cfTAPS provides multimodal information about cfDNA characteristics, including DNA methylation, tissue of origin, and DNA fragmentation. Integrated analysis of these epigenetic and genetic features enables accurate identification of early HCC and PDAC.

GSK3β as a novel promising target to overcome chemoresistance in pancreatic cancer

Pancreatic cancer is an aggressive malignancy with increasing incidence and poor prognosis due to its late diagnosis and intrinsic chemoresistance. Most pancreatic cancer patients present with locally advanced or metastatic disease characterized by inherent resistance to chemotherapy. These features pose a series of therapeutic challenges and new targets are urgently needed. Glycogen synthase kinase 3 beta (GSK3β) is a conserved serine/threonine kinase, which regulates key cellular processes including cell proliferation, DNA repair, cell cycle progression, signaling and metabolic pathways. GSK3β is implicated in non-malignant and malignant diseases including inflammation, neurodegenerative diseases, diabetes and cancer. GSK3β recently emerged among the key factors involved in the onset and progression of pancreatic cancer, as well as in the acquisition of chemoresistance. Intensive research has been conducted on key oncogenic functions of GSK3β and its potential as a druggable target; currently developed GSK3β inhibitors display promising results in preclinical models of distinct tumor types, including pancreatic cancer. Here, we review the latest findings about GSK-3β biology and its role in the development and progression of pancreatic cancer. Moreover, we discuss therapeutic agents targeting GSK3β that could be administered as monotherapy or in combination with other drugs to surmount chemoresistance. Several studies are also defining potential gene signatures to identify patients who might benefit from GSK3β-based therapeutic intervention. This detailed overview emphasizes the urgent need of additional molecular studies on the impact of GSK3β inhibition as well as structural analysis of novel compounds and omics studies of predictive biomarkers.

Targeting of promising transmembrane proteins for diagnosis and treatment of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal types of cancer due to the relatively late diagnosis and the limited therapeutic options. Current treatment regimens mainly comprise the cytotoxic agents gemcitabine and FOLFIRINOX. These compounds have shown limited efficacy and severe side effects, highlighting the necessity for earlier detection and the development of more effective, and better-tolerated treatments. Although targeted therapies are promising for the treatment of several types of cancer, identification of suitable targets for early diagnosis and targeted therapy of PDAC is challenging. Interestingly, several transmembrane proteins are overexpressed in PDAC cells that show low expression in healthy pancreas and may therefore serve as potential targets for treatment and/or diagnostic purposes. In this review we describe the 11 most promising transmembrane proteins, carefully selected after a thorough literature search. Favorable features and potential applications of each target, as well as the results of the preclinical and clinical studies conducted in the past ten years, are discussed in detail.

Type 2 Diabetes Mellitus Intersects With Pancreatic Cancer Diagnosis and Development

The relationship between type 2 diabetes mellitus (T2DM) and pancreatic cancer (PC) is complex. Diabetes is a known risk factor for PC, and new-onset diabetes (NOD) could be an early manifestation of PC that may be facilitate the early diagnosis of PC. Metformin offers a clear benefit of inhibiting PC, whereas insulin therapy may increase the risk of PC development. No evidence has shown that novel hypoglycemic drugs help or prevent PC. In this review, the effects of T2DM on PC development are summarized, and novel strategies for the prevention and treatment of T2DM and PC are discussed.

Hedgehog/GLI Signaling Pathway: Transduction, Regulation, and Implications for Disease

Simple Summary

The Hedgehog/GLI (Hh/GLI) pathway plays a major role during development and it is commonly dysregulated in many diseases, including cancer. This highly concerted series of ligands, receptors, cytoplasmic signaling molecules, transcription factors, and co-regulators is involved in regulating the biological functions controlled by this pathway. Activation of Hh/GLI in cancer is most often through a non-canonical method of activation, independent of ligand binding. This review is intended to summarize our current understanding of the Hh/GLI signaling, non-canonical mechanisms of pathway activation, its implication in disease, and the current therapeutic strategies targeting this cascade.

Abstract

The Hh/GLI signaling pathway was originally discovered in Drosophila as a major regulator of segment patterning in development. This pathway consists of a series of ligands (Shh, Ihh, and Dhh), transmembrane receptors (Ptch1 and Ptch2), transcription factors (GLI1–3), and signaling regulators (SMO, HHIP, SUFU, PKA, CK1, GSK3β, etc.) that work in concert to repress (Ptch1, Ptch2, SUFU, PKA, CK1, GSK3β) or activate (Shh, Ihh, Dhh, SMO, GLI1–3) the signaling cascade. Not long after the initial discovery, dysregulation of the Hh/GLI signaling pathway was implicated in human disease. Activation of this signaling pathway is observed in many types of cancer, including basal cell carcinoma, medulloblastoma, colorectal, prostate, pancreatic, and many more. Most often, the activation of the Hh/GLI pathway in cancer occurs through a ligand-independent mechanism. However, in benign disease, this activation is mostly ligand-dependent. The upstream signaling component of the receptor complex, SMO, is bypassed, and the GLI family of transcription factors can be activated regardless of ligand binding. Additional mechanisms of pathway activation exist whereby the entirety of the downstream signaling pathway is bypassed, and PTCH1 promotes cell cycle progression and prevents caspase-mediated apoptosis. Throughout this review, we summarize each component of the signaling cascade, non-canonical modes of pathway activation, and the implications in human disease, including cancer.

Evaluation of Somatic Mutations in Solid Metastatic Pan-Cancer Patients

Metastasis continues to be the primary cause of all cancer-related deaths despite the recent advancements in cancer treatments. To evaluate the role of mutations in overall survival (OS) and treatment outcomes, we analyzed 957 metastatic patients with seven major cancer types who had available molecular testing results with a FoundationOne CDx® panel. The most prevalent genes with somatic mutations were TP53, KRAS, APC, and LRP1B. In this analysis, these genes had mutation frequencies higher than in publicly available datasets. We identified that the somatic mutations were seven mutually exclusive gene pairs and an additional fifty-two co-occurring gene pairs. Mutations in the mutually exclusive gene pair APC and CDKN2A showed an opposite effect on the overall survival. However, patients with CDKN2A mutations showed significantly shorter OS (HR: 1.72, 95% CI: 1.34-2.21, p < 0.001) after adjusting for cancer type, age at diagnosis, and sex. Five-year post metastatic diagnosis survival analysis showed a significant improvement in OS (median survival 28 and 43 months in pre-2015 and post-2015 metastatic diagnosis, respectively, p = 0.00021) based on the year of metastatic diagnosis. Although the use of targeted therapies after metastatic diagnosis prolonged OS, the benefit was not statistically significant. However, longer five-year progression-free survival (PFS) was significantly associated with targeted therapy use (median 10.9 months (CI: 9.7-11.9 months) compared to 9.1 months (CI: 8.1-10.1 months) for non-targeted therapy, respectively, p = 0.0029). Our results provide a clinically relevant overview of the complex molecular landscape and survival mechanisms in metastatic solid cancers.

Identification of a lncRNA prognostic signature-related to stem cell index and its significance in colorectal cancer

Background: The relationship between long noncoding RNAs (lncRNAs) and the mRNA stemness index (mRNAsi) in colorectal cancer (CRC) is still unclear. Materials & methods: The mRNAsi, mRNAsi-related lncRNAs and their clinical significance were analyzed by bioinformatic approaches in The Cancer Genome Atlas (TCGA)-COREAD dataset. Results: mRNAsi was negatively related to pathological features but positively related to overall survival and recurrence-free survival in CRC. A five mRNAsi-related lncRNAs prognostic signature was further developed and showed independent prognostic factors related to overall survival in CRC patients, due to the five mRNAsi-related lncRNAs involved in several pathways of the cancer stem cells and malignant cancer cell phenotypes. Conclusion: The present study highlights the potential roles of mRNAsi-related lncRNAs as alternative prognostic markers.

Role of the TRP Channels in Pancreatic Ductal Adenocarcinoma Development and Progression

The transient receptor potential channels (TRPs) have been related to several different physiologies that range from a role in sensory physiology (including thermo- and osmosensation) to a role in some pathologies like cancer. The great diversity of functions performed by these channels is represented by nine sub-families that constitute the TRP channel superfamily. From the mid-2000s, several reports have shown the potential role of the TRP channels in cancers of multiple origin. The pancreatic cancer is one of the deadliest cancers worldwide. Its prevalence is predicted to rise further. Disappointingly, the treatments currently used are ineffective. There is an urgency to find new ways to counter this disease and one of the answers may lie in the ion channels belonging to the superfamily of TRP channels. In this review, we analyse the existing knowledge on the role of TRP channels in the development and progression of pancreatic ductal adenocarcinoma (PDAC). The functions of these channels in other cancers are also considered. This might be of interest for an extrapolation to the pancreatic cancer in an attempt to identify potential therapeutic interventions.

Nanomedicine to Overcome Multidrug Resistance Mechanisms in Colon and Pancreatic Cancer: Recent Progress

The development of drug resistance is one of the main causes of cancer treatment failure. This phenomenon occurs very frequently in different types of cancer, including colon and pancreatic cancers. However, the underlying molecular mechanisms are not fully understood. In recent years, nanomedicine has improved the delivery and efficacy of drugs, and has decreased their side effects. In addition, it has allowed to design drugs capable of avoiding certain resistance mechanisms of tumors. In this article, we review the main resistance mechanisms in colon and pancreatic cancers, along with the most relevant strategies offered by nanodrugs to overcome this obstacle. These strategies include the inhibition of efflux pumps, the use of specific targets, the development of nanomedicines affecting the environment of cancer-specific tissues, the modulation of DNA repair mechanisms or RNA (miRNA), and specific approaches to damage cancer stem cells, among others. This review aims to illustrate how advanced nanoformulations, including polymeric conjugates, micelles, dendrimers, liposomes, metallic and carbon-based nanoparticles, are allowing to overcome one of the main limitations in the treatment of colon and pancreatic cancers. The future development of nanomedicine opens new horizons for cancer treatment.

Identification of Vinyl Sulfone Derivatives as EGFR Tyrosine Kinase Inhibitor: In Vitro and In Silico Studies

Epidermal growth factor receptor (EGFR), overexpressed in many types of cancer, has been proved as a high potential target for targeted cancer therapy due to its role in regulating proliferation and survival of cancer cells. In the present study, a series of designed vinyl sulfone derivatives was screened against EGFR tyrosine kinase (EGFR-TK) using in silico and in vitro studies. The molecular docking results suggested that, among 78 vinyl sulfones, there were eight compounds that could interact well with the EGFR-TK at the ATP-binding site. Afterwards, these screened compounds were tested for the inhibitory activity towards EGFR-TK using ADP-Glo™ kinase assay, and we found that only VF16 compound exhibited promising inhibitory activity against EGFR-TK with the IC₅₀ value of 7.85 ± 0.88 nM. In addition, VF16 showed a high cytotoxicity with IC₅₀ values of 33.52 ± 2.57, 54.63 ± 0.09, and 30.38 ± 1.37 µM against the A431, A549, and H1975 cancer cell lines, respectively. From 500-ns MD simulation, the structural stability of VF16 in complex with EGFR-TK was quite stable, suggesting that this compound could be a novel small molecule inhibitor targeting EGFR-TK.

GSK-3β Can Regulate the Sensitivity of MIA-PaCa-2 Pancreatic and MCF-7 Breast Cancer Cells to Chemotherapeutic Drugs, Targeted Therapeutics and Nutraceuticals

Glycogen synthase kinase-3 (GSK-3) is a regulator of signaling pathways. KRas is frequently mutated in pancreatic cancers. The growth of certain pancreatic cancers is KRas-dependent and can be suppressed by GSK-3 inhibitors, documenting a link between KRas and GSK-3. To further elucidate the roles of GSK-3β in drug-resistance, we transfected KRas-dependent MIA-PaCa-2 pancreatic cells with wild-type (WT) and kinase-dead (KD) forms of GSK-3β. Transfection of MIA-PaCa-2 cells with WT-GSK-3β increased their resistance to various chemotherapeutic drugs and certain small molecule inhibitors. Transfection of cells with KD-GSK-3β often increased therapeutic sensitivity. An exception was observed with cells transfected with WT-GSK-3β and sensitivity to the BCL2/BCLXL ABT737 inhibitor. WT-GSK-3β reduced glycolytic capacity of the cells but did not affect the basal glycolysis and mitochondrial respiration. KD-GSK-3β decreased both basal glycolysis and glycolytic capacity and reduced mitochondrial respiration in MIA-PaCa-2 cells. As a comparison, the effects of GSK-3 on MCF-7 breast cancer cells, which have mutant PIK3CA, were examined. KD-GSK-3β increased the resistance of MCF-7 cells to chemotherapeutic drugs and certain signal transduction inhibitors. Thus, altering the levels of GSK-3β can have dramatic effects on sensitivity to drugs and signal transduction inhibitors which may be influenced by the background of the tumor.

Nobiletin Inhibits Cell Growth, Migration and Invasion, and Enhances the Anti-Cancer Effect of Gemcitabine on Pancreatic Cancer Cells

Natural products are very promising adjuvants with a variety of biological activities. Nobiletin, a citrus polymethoxyflavone, has been shown to exert an anticancer effect in various cell lines. In this study, we investigated the effects of nobiletin on cell viability, sphere formation, migration and invasion of pancreatic cancer cells, and the underlying mechanisms. Our results demonstrate that nobiletin significantly inhibited PANC-1 cell migration and invasion, and these effects were associated with downregulation of MMP-2. We also found that nobiletin, in a low concentration, exhibited a strong inhibitory effect on sphere formation. The potential molecular mechanisms were related to significant downregulation of p-mTOR and p-STAT3. Furthermore, we found that nobiletin combined with gemcitabine synergistically inhibited PANC-1 cell viability and sphere formation. The underlying mechanisms of the synergistic inhibition on growth were associated with decreases in p-STAT3 expression. Overall, our results suggest that nobiletin may be a promising candidate for pancreatic cancer adjuvant treatment.

Expression profile, molecular functions, and prognostic significance of miRNAs in primary colorectal cancer stem cells

MicroRNAs (miRNAs) are known to drive the pathogenesis of colorectal cancer (CRC) via the regulation of cancer stem cells (CSCs). We studied the miRNA expression profile of primary CSCs isolated from patients with CRC (pCRCSCs). Compared to pCRCSC-derived differentiated cells, 98 differentially expressed miRNAs were identified in pCRCSCs. Target genes encoding pCRCSC-related miRNAs were identified using a combination of miRNA target databases and miRNA-mRNA regulatory networks from the same patient. The pCRCSC-related miRNA target genes were associated with pathways contributing to malignant phenotypes, including I-kappa B kinase/NF-kappa B signaling, signal transduction by p53 class mediator, Ras signaling, and cGMP-PKG signaling. The pCRCSC-related miRNA expression signature was independently associated with poor overall survival in both the training and validation cohorts. We have thus identified several pCRCSC-related miRNAs with oncogenic potential that could serve as prognostic biomarkers for CRC.

Glycogen Synthase Kinase-3 Beta Expression Correlates With Worse Overall Survival in Non-Small Cell Lung Cancer-A Clinicopathological Series

Background

Glycogen Synthase Kinase-3 beta (GSK-3β) regulates diverse cell functions including metabolic activity, signaling and structural proteins. GSK-3β phosphorylates target pro-oncogenes and regulates programmed cell death-ligand 1 (PD-L1). This study investigated the correlation between GSK-3β expression and clinically relevant molecular features of lung adenocarcinoma (PDL1 score, PTEN expression and driver mutations).

Methods

We evaluated 95 lung cancer specimens from biopsies and surgical resections. Immunohistochemistry was performed to analyze the expression of GSK-3β, PTEN, and PDL1. Epidemiological data, molecular characteristics and staging were evaluated from medical records. The histologic classification was performed by an experienced pulmonary pathologist.

Results

Most patients were female (52.6%) and the majority had a positive smoking history. The median age was 68.3 years, with individuals over 60 years accounting for 82.1%. The predominant histological subtype was adenocarcinoma (69.5%), followed by squamous cell carcinoma (20.0%). GSK-3β expression in tumors was cytoplasmic with a dotted pattern and perinuclear concentration, with associated membranous staining. Seven (7.3%) tumors had associated nuclear expression localization. Seventy-seven patients (81.1%) had advanced clinical-stage tumors. GSK-3β was positive in 75 tumors (78%) and GSK3-positive tumors tended to be diagnosed at advanced stages. Among stage III/IV tumors, 84% showed GSK3 positivity (p= 0.007). We identified a statistically significant association between GSK-3β and PTEN in the qualitative analysis (p 0.021); and when comparing PTEN to GSK-3β intensity 2+ (p 0.001) or 3+ expression (> 50%) – p 0.013. GSK-3β positive tumors with a high histological score had a worse overall survival.

Conclusion

We identified the histological patterns of GSK-3β expression and evaluated its potential as marker for overall survival, establishing a simple histological score to measure the evaluated status in resected tissues. The use of GSK-3β expression as an immune response biomarker remains a challenge. Future studies will seek to explain the role of its interaction with PTEN.

Crosstalk between miRNAs and signaling pathways involved in pancreatic cancer and pancreatic ductal adenocarcinoma

Pancreatic cancer (PC) is the seventh leading cause of cancer-related deaths worldwide with 5-year survival rates below 8%. Most patients with PC and pancreatic ductal adenocarcinoma (PDAC) die after relapse and cancer progression as well as resistance to treatment. Pancreatic tumors contain a high desmoplastic stroma that forms a rigid mass and has a potential role in tumor growth and metastasis. PC initiates from intraepithelial neoplasia lesions leading to invasive cancer through various pathways. These lesions harbor particular changes in signaling pathways involved in the tumorigenesis process. These events affect both the epithelial cells, including the tumor and the surrounding stroma, and eventually lead to the formation of complex signaling networks. Genetic studies of PC have revealed common molecular features such as the presence of mutations in KRAS gene in more than 90% of patients, as well as the inactivation or deletion mutations of some tumor suppressor genes including TP53, CDKN2A, and SMAD4. In recent years, studies have also identified different roles of microRNAs in PC pathogenesis as well as their importance in PC diagnosis and treatment, and their involvement in various signaling pathways. In this study, we discussed the most common pathways involved in PC and PDAC as well as their role in tumorigenesis and progression. Furthermore, the miRNAs participating in the regulation of these signaling pathways in PC progression are summarized in this study. Therefore, understanding more about pathways involved in PC can help with the development of new and effective therapies in the future.

Fucoxanthin extracted from Laminaria Japonica inhibits metastasis and enhances the sensitivity of lung cancer to Gefitinib

ETHNOPHARMACOLOGICAL RELEVANCE

Laminaria japonica, a brown seaweed, has been used in Traditional Chinese Medicine (TCM) to treat a variety of diseases including lung cancer.

AIM OF THE STUDY

To demonstrate the effects of Fucoxanthin (FX), a major active component extracted from Laminaria japonica on metastasis and Gefitinib (Gef) sensitivity in human lung cancer cells both in vitro and in vivo.

MATERIALS AND METHODS

Invasion and migration of lung cancer cells were detected using the wound healing assay and transwell assay. Epithelial-to-mesenchymal transition (EMT) factors and PI3K/AKT/NF-κB pathways were analyzed by western blotting. RNA interference (RNAi) technology was used to silence TIMP-2 gene expression in A549 cells. The anti-metastatic effect of FX was evaluated in vivo in an experimental lung metastatic tumor model. On the other hand, cell counting kit-8 assay was used to study the cell viability of human lung cancer PC9 cells and Gef resistant PC9 cells (PC9/G) after Gef, FX or FX combined with Gef treatment. PC9 xenograft model was established to explore the anti-tumor effect of FX or combined with Gef. Immunohistochemistry staining assay and immunofluorescence staining assay were used to reveal the effects of FX on lung cancer cell proliferation and apoptosis.

RESULTS

FX was able to significantly inhibit lung cancer cells migration and invasion in vitro. FX suppressed the expressions of Snail, Twist, Fibronectin, N-cadherin, MMP-2, PI3K, p-AKT and NF-κB, and increased the expression of TIMP-2. Furthermore, knockdown of TIMP-2 attenuated FX-mediated invasion inhibition. Additionally, we demonstrated that FX inhibited lung cancer cells metastasis in vivo. The anti-metastatic effects of FX on lung cancer cells might be attributed to inhibition of EMT and PI3K/AKT/NF-κB pathway. We further demonstrated that the anti-tumor activity of FX was not only limited to the drug sensitive cell lines, but also prominent on lung cancer cells with Gef resistant phenotype. Furthermore, in vivo xenograft assay confirmed that FX inhibited tumor growth and enhanced the sensitivity of lung cancer cells to Gef and this effect may be due to inhibition of tumor cell proliferation and activation of apoptosis.

CONCLUSION

Collectively, our findings suggested that FX suppresses metastasis of lung cancer cells and overcomes EGFR TKIs resistance. Thus, FX is worthy of further investigation as a drug candidate for the treatment of lung cancer.

Expression and prognostic analyses of SCAMPs in pancreatic adenocarcinoma

Due to the difficulties in early diagnosis of pancreatic adenocarcinoma (PAAD), many patients fail to receive optimal therapeutic regimens. The Secretory-Carrier-Membrane-Proteins (SCAMPs) are known to be dysregulated in a range of human diseases due to their characterized roles in mammalian cell exocytosis inferred from their functions as integral membrane proteins. However, the expression and prognostic value of SCAMPs in PAAD is poorly characterized. We compared cancer vs. healthy tissue and found that the expression of SCAMPs1-4 was upregulated in PAAD compared to normal tissue. In contrast, SCAMP5 expression was downregulated in PAAD. Moreover, the expression of SCAMPs1-4 was enhanced in PAAD cell lines according to Cancer Cell Line public database. Furthermore, the HPA, GEPIA databases and immunohistochemical analysis from 238 patients suggested that the loss of SCAMP1 led to improved overall survival (OS), whilst lower SCAMP5 levels led to a poorer OS. The univariate and multivariate analysis showed that SCAMP1 and SCAMP5 expression were independent prognostic factors of PAAD. In addition, the cBioPortal for Cancer Genomics, LinkedOmics datasets, and the GEPIA were used to identify the co-expression genes of SCAMP1,5 and the correlation between SCAMPs members. We conclude that SCAMPs 1 and 5 significantly represent promising diagnosis and prognostic biomarkers.

Sensitivity of pancreatic cancer cells to chemotherapeutic drugs, signal transduction inhibitors and nutraceuticals can be regulated by WT-TP53

Pancreatic ductal adenocarcinoma (PDAC) is a highly metastatic malignancy. Approximately 85% of pancreatic cancers are classified as PDACs. The survival of PDAC patients is very poor and only 5-10% of patients survive 5 years after diagnosis. Mutations at the KRAS and TP53 gene are frequently observed in PDAC patients. The PANC-28 cell line lacks wild-type (WT) TP53. In the following study, we have investigated the effects of restoration of WT TP53 activity on the sensitivity of PANC-28 pancreatic cancer cells to various drugs which are used to treat PDAC patients as well as other cancer patients. In addition, we have examined the effects of signal transduction inhibitors which target critical pathways frequently deregulated in cancer. The effects of the anti-diabetes drug metformin and the anti-malarial drug chloroquine were also examined as these drugs may be repurposed to treat other diseases. Finally, the effects of certain nutraceuticals which are used to treat various ailments were also examined. Introduction of WT-TP53 activity in PANC-28 PDAC cells, can increase their sensitivity to various drugs. Attempts are being made clinically to increase TP53 activity in various cancer types which will often inhibit cell growth by multiple mechanisms.

Selective inhibition of stemness through EGFR/FOXA2/SOX9 axis reduces pancreatic cancer metastasis

Pancreatic cancer (PC) is difficult to defeat due to mechanism (s) driving metastasis and drug resistance. Cancer stemness is a major challenging phenomenon associated with PC metastasis and limiting therapy efficacy. In this study, we evaluated the pre-clinical and clinical significance of eradicating pancreatic cancer stem cells (PCSC) and its components using a pan-EGFR inhibitor afatinib in combination with gemcitabine. Afatinib in combination with gemcitabine, significantly reduced Kras^G12D/+; Pdx-1 Cre (KC) (P<0.01) and Kras^G12D/+; p53^R172H/+; Pdx-1 Cre (KPC) (P<0.05) derived mouse tumoroids and KPC-derived murine syngeneic cell line growth compared to gemcitabine/afatinib alone treatment. The drug combination also reduced PC xenograft tumor burden (P<0.05) and the incidence of metastasis by affecting key stemness markers, as confirmed by co-localization studies. Moreover, the drug combination significantly decreases the growth of various PC patient-derived organoids (P<0.001). We found that SOX9 is significantly overexpressed in high-grade PC tumors (P<0.05) and in chemotherapy-treated patients compared to chemo-naïve patients (P<0.05). These results were further validated using publicly available datasets. Moreover, afatinib alone or in combination with gemcitabine decreased stemness and tumorspheres by reducing phosphorylation of EGFR family proteins, ERK, FAK, and CSC markers. Mechanistically, afatinib treatment decreased CSC markers by downregulating SOX9 via FOXA2. Indeed, EGFR and FOXA2 depletion reduced SOX9 expression in PCSCs. Taken together, pan EGFR inhibition by afatinib impedes PCSCs growth and metastasis via the EGFR/ERK/FOXA2/SOX9 axis. This novel mechanism of panEGFR inhibitor and its ability to eradicate CSC may serve as a tailor-made approach to enhance chemotherapeutic benefits in other cancer types.

Molecular Therapeutics of Pancreatic Ductal Adenocarcinoma: Targeted Pathways and the Role of Cancer Stem Cells

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers in humans due to late detection and highly metastatic characteristics. PDAC cells vary in their tumorigenic capabilities with the presence of a subset of PDAC cells known as pancreatic cancer stem cells (CSCs), which are more resistant to currently used therapeutics. Here, we describe the role of CSCs and tumour stroma in developing therapeutic strategies for PDAC and suggest that developmental plasticity could be considered a hallmark of cancers. We provide an overview of the molecular targets in PDAC treatments, including targeted therapies of cellular processes such as proliferation, evasion of growth suppressors, activating metastasis, and metabolic effects. Since PDAC is an inflammation-driven cancer, we also revisit therapeutic strategies targeting inflammation and immunotherapy. Lastly, we suggest that targeting epigenetic mechanisms opens therapeutic routes for heterogeneous cancer cell populations, including CSCs.

Expression and role of nuclear receptor-interacting protein 1 (NRIP1) in stomach adenocarcinoma

Background

Nuclear receptor-interacting protein 1 (NRIP1), also named NR140, has been observed differentially express in multiple cancers, but the expression levels and the prognostic role of NRIP1 in stomach adenocarcinoma (STAD) remain unclear.

Methods

We used the Gene Expression Profiling Interactive Analysis (GEPIA) to analyze the NRIP1 expression levels in STAD, subgroups analysis of expression of NRIP1 via the UALCAN dataset. Further, cBioPortal was used to investigate the aberration type, co-mutations status, and located mutation of NRIP1. Correlated genes, and kinases, microRNA (miRNA), and transcription factor (TF) targets were identified using LinkedOmics. The Kaplan-Meier (K-M) plotter was used to analyze the prognosis of NRIP1 and the significantly correlated genes in STAD. Then, the tumor immune estimation resource (Timer) was used to explore the relation between NRIP1 and the immune cell infiltration, and the role of immune cells in STAD. The Human Protein Atlas (HPA) was used to confirm the NRIP1 protein express in STAD stomach tissue and normal stomach tissue.

Results

NRIP1 significantly overexpress in STAD, and the NRIP1 expression levels were impacted by clinical features. Overexpression of NRIP1 indicated the poor prognosis of STAD. Functional enrichment analysis showed the NRIP1 mainly enriched in immune response-regulating signaling pathway, cell-substrate adhesion, mRNA processing, and pathway in cancer. Overexpression USP25, SNYJ1 indicated the poor outcome of STAD, but the overexpression of BACH1 indicated protective biomarker. MIR-331 and MIR-132 have important role in STAD. Further, NRIP1 had a significant relation with immune infiltrates and other defined genes that significantly impact immune infiltrates. Immunohistochemical showed NRIP1 protein was higher in STAD than normal sample.

Conclusions

In this study, we revealed that overexpression of NRIP1 in the STAD sample compared to normal samples, NRIP1 significantly associated with macrophage. The high expression levels of NRIP1 and more macrophage infiltration led to poor prognosis of STAD.

Potential diagnostic and therapeutic roles of exosomes in pancreatic cancer

Pancreatic cancer (PaCa) is considered an aggressive but still asymptomatic malignancy. Due to the lack of effective diagnostic markers, PaCa is often diagnosed during late metastatic stages. Besides surgical resection, no other treatment appears to be effective during earlier stages of the disease. Exosomes are related to a class of nanovesicles coated by a bilayer lipid membrane and enriched in protein, nucleic acid, and lipid contents. They are widely present in human body fluids, including blood, saliva, and pancreatic duct fluid, with functions in signal transduction and material transport. A large number of studies have suggested for a crucial role for exosomes in PaCa, which may be utilized to improve its future diagnosis and treatment, but the underlying molecular mechanisms as well as their potential clinical applications are largely unknown. By collecting and analyzing the most up-to-date literature, here we summarize the current progress of the clinical applications related to exosomes in PaCa. Therefore, we presently provide some rationale for the potential value of exosomes in PaCa, thereby promoting putative applications in targeted PaCa treatment.

PSMD11, PTPRM and PTPRB as novel biomarkers of pancreatic cancer progression

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) has the lowest survival rate of all major cancers. Surgery is the only curative intent therapy, but the majority of patients experience disease relapse. Thus, patients who do not benefit from highly morbid surgical resection needs to be identified and offered palliative chemotherapy instead. In this pilot study, we aimed to identify differentially regulated proteins in plasma and plasma derived microparticles from PDAC patients with poor and good prognosis.

METHODS

Plasma and plasma derived microparticle samples were obtained before surgical resection from PDAC patients. Sequential Windowed Acquisition of all Theoretical fragment ion spectra - Mass Spectrometry (SWATH-MS) proteomic analysis was performed to identify and quantify proteins in these samples. Statistical analysis was performed to identify biomarkers for poor prognosis.

RESULTS

A total of 482 and 1024 proteins were identified from plasma and microparticle samples, respectively, by SWATH-MS analysis. Statistical analysis of the data further identified nine and six differentially (log₂ratio > 1, p < .05) expressed proteins in plasma and microparticles, respectively. Protein tyrosine phosphatases, PTPRM and PTPRB, were decreased in plasma of patients with poor PDAC prognosis, while proteasomal subunit PSMD11 was increased in microparticles of patients with poor prognosis.

CONCLUSION AND GENERAL SIGNIFICANCE

A novel blood-based biomarker signature for PDAC prognosis was identified.

Cytotoxicity study of the interleukin-12-expressing recombinant Newcastle disease virus strain, rAF-IL12, towards CT26 colon cancer cells in vitro and in vivo

Background

Oncolytic viruses have emerged as an alternative therapeutic modality for cancer as they can replicate specifically in tumour cells and induce toxic effects leading to apoptosis. Despite the great potentials and promising results shown in multiple studies, it appears that their efficacy is still moderate and deemed as not sufficient in clinical studies. In addressing this issue, genetic/molecular engineering approach has paved its way to improve the therapeutic efficacy as observed in the case of herpes simplex virus (HSV) expressing granulocyte–macrophage colony-stimulating factor (GM-CSF). This study aimed to explore the cytotoxicity effects of recombinant NDV strain AF2240-i expressing interleukin-12 (rAF-IL12) against CT26 colon cancer cells.

Methods

The cytotoxicity effect of rAF-IL12 against CT26 colon cancer cell line was determined by MTT assay. Based on the IC₅₀ value from the anti-proliferative assay, further downward assays such as Annexin V FITC and cell cycle progression were carried out and measured by flow cytometry. Then, the in vivo study was conducted where the rAF-IL12 viral injections were given at the intra-tumoral site of the CT26 tumour-burden mice. At the end of the experiment, serum biochemical, T cell immunophenotyping, serum cytokine, histopathology of tumour and organ section, TUNEL assay, and Nanostring gene expression analysis were performed.

Results

The rAF-IL12 induced apoptosis of CT26 colon cancer cells in vitro as revealed in the Annexin V FITC analysis and also arrested the cancer cells progression at G₁ phase of the cell cycle analysis. On the other hand, the rAF-IL12 significantly (p < 0.05) inhibited the growth of CT26 tumour in Balb/c mice and had regulated the immune system by increasing the level of CD4 + , CD8 + , IL-2, IL-12, and IFN-γ. Furthermore, the expression level of apoptosis-related genes (bax and p53) was up-regulated as a result of the rAF-IL12 treatment. Additionally, the rAF-IL12 had also down-regulated the expression level of KRAS, BRAF, MAPK1, Notch1, CCL2, and VEGF oncogenes. Besides, rAF-IL12 intra-tumoral delivery was considered safe and not hazardous to the host as evidenced in pathophysiology of the normal tissues and organs of the mice as well as from the serum biochemistry profile of liver and kidney.

Conclusions

These results indicated that rAF-IL12 had better anti-tumoral and cytotoxicity effects compared to its parental wild-type, AF2240-i in combatting the CT26 colon cancer model.

GSK-3 and miRs: Master regulators of therapeutic sensitivity of cancer cells

Glycogen synthetase kinase-3 (GSK-3) and microRNAs (miRs) affect many critical signaling pathways important in cell growth. GSK-3 is a serine/threonine (S/T) protein kinase. Often when GSK-3 phosphorylates other proteins, they are inactivated and the signaling pathway is shut down. The PI3K/PTEN/AKT/GSK3/mTORC1 pathway plays key roles in regulation of cell growth, apoptosis, drug resistance, malignant transformation and metastasis and is often deregulated in cancer. When GSK-3 is phosphorylated by AKT it is inactivated and this often leads to growth promotion. When GSK-3 is not phosphorylated by AKT or other kinases at specific negative-regulatory residues, it can modify the activity of many proteins by phosphorylation, some of these proteins promote while others inhibit cell proliferation. This is part of the conundrum regarding GSK-3. The central theme of this review is the ability of GSK-3 to serve as either a tumor suppressor or a tumor promoter in cancer which is likely due to its diverse protein substrates. The effects of multiple miRs which bind mRNAs encoding GSK-3 and other signaling molecules and how they affect cell growth and sensitivity to various therapeutics will be discussed as they serve to regulate GSK-3 and other proteins important in controlling proliferation.

Lipid metabolism alteration contributes to and maintains the properties of cancer stem cells

Lipids, the basic components of the cell membrane, execute fundamental roles in almost all the cell activities including cell-cell recognition, signalling transduction and energy supplies. Lipid metabolism is elementary for life sustentation that balances activity between synthesis and degradation. An accumulating amount of data has indicated abnormal lipid metabolism in cancer stem cells (CSCs), and that the alteration of lipid metabolism exerts a great impact on CSCs' properties such as the capability of self-renewal, differentiation, invasion, metastasis, and drug sensitivity and resistance. CSCs' formation and maintenance cannot do without the regulation of fatty acids and cholesterol. In normal cells and embryonic development, fatty acids and cholesterol metabolism are regulated by some important signalling pathways (such as Hedgehog, Notch, Wnt signalling pathways); these signalling pathways also play crucial roles in initiating and/or maintaining CSCs' properties, and such signalling is shown to be commonly modulated by the abnormal lipid metabolism in CSCs; on the other hand, the altered lipid metabolism in turn modifies the cell signalling and generates additional impacts on CSCs. Metabolic rewiring is considered as an ideal hallmark of CSCs, and metabolic alterations would be promising therapeutic targets of CSCs for aggressive tumors. In this review, we summarize the most updated findings of lipid metabolic abnormalities in CSCs and prospect the potential applications of targeting lipid metabolism for anticancer treatment.

Small Molecule KRAS Inhibitors: The Future for Targeted Pancreatic Cancer Therapy?

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest solid tumors in the world. Currently, there are no approved targeted therapies for PDAC. Mutations in Kirsten rat sarcoma viral oncogene homologue (KRAS) are known to be a major driver of PDAC progression, but it was considered an undruggable target until recently. Moreover, PDAC also suffers from drug delivery issues due to the highly fibrotic tumor microenvironment. In this perspective, we provide an overview of recent developments in targeting mutant KRAS and strategies to overcome drug delivery issues (e.g., nanoparticle delivery). Overall, we propose that the antitumor effects from novel KRAS inhibitors along with strategies to overcome drug delivery issues could be a new therapeutic way forward in PDAC.

Transgenic expression of Sag/Rbx2 E3 causes early stage tumor promotion, late stage cytogenesis and acinar loss in the Kras-PDAC model

SAG (Sensitive to Apoptosis Gene), also known as RBX2 or ROC2, is a RING component of CRL (Cullin-RING ligase), required for its activity. Our previous studies showed that Sag/Rbx2 co-operated with Kras or Pten loss to promote tumorigenesis in the lung and prostate, respectively, but antagonized Kras to inhibit skin tumorigenesis, suggesting a tissue/context dependent function of Sag. The role of SAG in KRAS-induced pancreatic tumorigenesis is unknown. In this study, we mined a cancer database and found that SAG is overexpressed in pancreatic cancer tissues and correlates with decreased patient survival. Whether Sag overexpression plays a causal role in pancreatic tumorigenesis is unknown. Here, we reported the generation of Sag transgenic mouse model alone (CS), or in combination with KrasG12D, driven by p48-Cre (KCS mice) for pancreatic specific Sag expression. Sag transgenic expression alone has no phenotypical abnormality, but in combination with KrasG12D promotes ADM (acinar-to-ductal metaplasia) conversion in vitro and mPanIN1 formation in vivo at the early stage, and impairs pancreatic functions at the late stage, as evidenced by poor glucose tolerance and significantly reduced α-Amylase activity, and induction of cytogenesis and acinar cell loss, eventually leading to atrophic pancreata and shortened mouse life-span. Mechanistically, Sag transgenic expression altered several key signaling pathways, particularly inactivation of mTORC1 signaling due to Deptor accumulation, and activation of the antioxidant Nrf2-Nqo1 axis. Thus, Sag plays a stage dependent promotion (early) and fate-changing (late) role during Kras-pancreatic tumorigenesis, likely via regulating its key substrates, which control growth-related signal transduction pathways.