Targeting RAS signalling pathways in cancer therapy

Step by step analysis on gene datasets of growth phases in hematopoietic stem cells

Background

Umbilical cord blood hematopoietic stem cells (UCB-HSCs) have important roles in the treatment of illnesses based on their self-renewal and potency characteristics. Knowing the gene profiles and signaling pathways involved in each step of the cell cycle could improve the therapeutic approaches of HSCs. The aim of this study was to predict the gene profiles and signaling pathways involved in the G0, G1, and differentiation stages of HSCs.

Methods

Interventional (n = 8) and non-interventional (n = 3) datasets were obtained from the Gene Expression Omnibus (GEO) database, and were crossed and analyzed to determine the high- and low-express genes related to each of the G0, G1, and differentiation stages of HSCs. Then, the scores of STRING were annotated to the gene data. The gene networks were constructed using Cytoscape software, and enriched with the KEGG and GO databases.

Results

The high- and low-express genes were determined due to inter and intra intersections of the interventional and non-interventional data. The non-interventional data were applied to construct the gene networks (n = 6) with the nodes improved using the interventional data. Several important signaling pathways were suggested in each of the G0, G1, and differentiation stages.

Conclusion

The data revealed that the different signaling pathways are activated in each of the G0, G1, and differentiation stages so that their genes may be targeted to improve the HSC therapy.

Single cell spatial biology over developmental time can decipher pediatric brain pathologies

Pediatric low grade brain tumors and neurodevelopmental disorders share proteins, signaling pathways, and networks. They also share germline mutations and an impaired prenatal differentiation origin. They may differ in the timing of the events and proliferation. We suggest that their pivotal distinct, albeit partially overlapping, outcomes relate to the cell states, which depend on their spatial location, and timing of gene expression during brain development. These attributes are crucial as the brain develops sequentially, and single-cell spatial organization influences cell state, thus function. Our underlying premise is that the root cause in neurodevelopmental disorders and pediatric tumors is impaired prenatal differentiation. Data related to pediatric brain tumors, neurodevelopmental disorders, brain cell (sub)types, locations, and timing of expression in the developing brain are scant. However, emerging single cell technologies, including transcriptomic, spatial biology, spatial high-resolution imaging performed over the brain developmental time, could be transformational in deciphering brain pathologies thereby pharmacology.

Dual-targeted NAMPT inhibitors as a progressive strategy for cancer therapy

In mammals, nicotinamide phosphoribosyltransferase (NAMPT) is a crucial enzyme in the nicotinamide adenine dinucleotide (NAD+) synthesis pathway catalyzing the condensation of nicotinamide (NAM) with 5-phosphoribosyl-1-pyrophosphate (PRPP) to produce nicotinamide mononucleotide (NMN). Given the pivotal role of NAD+ in a range of cellular functions, including DNA synthesis, redox reactions, cytokine generation, metabolism, and aging, NAMPT has become a promising target for many diseases, notably cancer. Therefore, various NAMPT inhibitors have been reported and classified as first and second-generation based on their chemical structures and design strategies, dual-targeted being one. However, most NAMPT inhibitors suffer from several limitations, such as dose-dependent toxicity and poor pharmacokinetic properties. Consequently, there is no clinically approved NAMPT inhibitor. Hence, research on discovering more effective and less toxic dual-targeted NAMPT inhibitors with desirable pharmacokinetic properties has drawn attention recently. This review summarizes the previously reported dual-targeted NAMPT inhibitors, focusing on their design strategies and advantages over the single-targeted therapies.

Regulatory effects of statins on Akt signaling for prevention of cancers

Statins, which are primarily used as lipid-lowering drugs, have been found to exhibit anti-tumor effects through modulating and interfering with various signaling pathways. In observational studies, statin use has been associated with a significant reduction in the progression of various cancers, including colon, lung, prostate, pancreas, and esophagus cancer, as well as melanoma and B and T cell lymphoma. The mevalonate pathway, which is affected by statins, plays a crucial role in activating Rho, Ras, and Rab proteins, thereby impacting the proliferation and apoptosis of tumor cells. Statins block this pathway, leading to the inhibition of isoprenoid units, which are critical for the activation of these key proteins, thereby affecting cancer cell behavior. Additionally, statins affect MAPK and Cdk2, which in turn reduce the expression of p21 and p27 cyclin-dependent kinase inhibitors. Akt signaling plays a crucial role in key cancer cell features like proliferation, invasion, and apoptosis by activating multiple effectors in downstream pathways such as FOXO, PTEN, NF-κB, GSK3β, and mTOR. The PI3K/Akt signaling is necessary for many events in the metastatic pathway and has been implicated in the resistance to cytostatic drugs. The Akt/PTEN axis is currently attracting great interest for its role in carcinogenesis. Statins have been shown to activate the purinergic receptor P2X7 and affect Akt signaling, which may have important anti-cancer effects. Hence, targeting Akt shows promise as an effective approach to cancer prevention and therapy. This review aims to provide a comprehensive discussion on the specific impact of statins through Akt signaling in different types of cancer.

Identification of Ppy-lineage cells as a novel origin of pancreatic ductal adenocarcinoma

The Ppy gene encodes pancreatic polypeptide (PP) secreted by PP- or γ-cells, which are a subtype of endocrine cells localised mainly in the islet periphery. For a detailed characterisation of PP cells, we aimed to establish PP cell lines. To this end, we generated a mouse model harbouring the SV40 large T antigen (TAg) in the Rosa26 locus, which is expressed upon Ppy-promoter-mediated Cre-loxP recombination. Whereas Insulin1-CreERT-mediated TAg expression in beta cells resulted in insulinoma, surprisingly, Ppy-Cre-mediated TAg expression resulted in the malignant transformation of Ppy-lineage cells. These mice showed distorted islet structural integrity at 5 days of age compared with normal islets. CK19+ duct-like lesions contiguous with the islets were observed at 2 weeks of age, and mice developed aggressive pancreatic ductal adenocarcinoma (PDAC) at 4 weeks of age, suggesting that PDAC can originate from the islet/endocrine pancreas. This was unexpected as PDAC is believed to originate from the exocrine pancreas. RNA-sequencing analysis of Ppy-lineage islet cells from 7-day-old TAg+ mice showed a downregulation and an upregulation of endocrine and exocrine genes, respectively, in addition to the upregulation of genes and pathways associated with PDAC. These results suggest that the expression of an oncogene in Ppy-lineage cells induces a switch from endocrine cell fate to PDAC. Our findings demonstrate that Ppy-lineage cells may be an origin of PDAC and may provide novel insights into the pathogenesis of pancreatic cancer, as well as possible therapeutic strategies. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Targeting guanine nucleotide exchange factors for novel cancer drug discovery

INTRODUCTION

Guanine nucleotide exchange factors (GEFs) regulate the activation of small GTPases (G proteins) of the Ras superfamily proteins controlling cellular functions. Ras superfamily proteins act as 'molecular switches' that are turned 'ON' by guanine exchange. There are five major groups of Ras family GTPases: Ras, Ran, Rho, Rab and Arf, with a variety of different GEFs regulating their GTP loading. GEFs have been implicated in various diseases including cancer. This makes GEFs attractive targets to modulate signaling networks controlled by small GTPases.

AREAS COVERED

In this review, the roles and mechanisms of GEFs in malignancy are outlined. The mechanism of guanine exchange activity by GEFs on a small GTPase is illustrated. Then, some examples of GEFs that are significant in cancer are presented with a discussion on recent progress in therapeutic targeting efforts using a variety of approaches.

EXPERT OPINION

Recently, GEFs have emerged as potential therapeutic targets for novel cancer drug development. Targeting small GTPases is challenging; thus, targeting their activation by GEFs is a promising strategy. Most GEF-targeted drugs are still in preclinical development. A deeper biological understanding of the underlying mechanisms of GEF activity and utilizing advanced technology are necessary to enhance drug discovery for GEFs in cancer.

Peptostreptococcus stomatis promotes colonic tumorigenesis and receptor tyrosine kinase inhibitor resistance by activating ERBB2-MAPK

Peptostreptococcus stomatis (P. stomatis) is enriched in colorectal cancer (CRC), but its causality and translational implications in CRC are unknown. Here, we show that P. stomatis accelerates colonic tumorigenesis in ApcMin/+ and azoxymethane/dextran sodium sulfate (AOM-DSS) models by inducing cell proliferation, suppressing apoptosis, and impairing gut barrier function. P. stomatis adheres to CRC cells through its surface protein fructose-1,6-bisphosphate aldolase (FBA) that binds to the integrin α6/β4 receptor on CRC cells, leading to the activation of ERBB2 and the downstream MEK-ERK-p90 cascade. Blockade of the FBA-integrin α6/β4 abolishes ERBB2-mitogen-activated protein kinase (MAPK) activation and the protumorigenic effect of P. stomatis. P. stomatis-driven ERBB2 activation bypasses receptor tyrosine kinase (RTK) blockade by EGFR inhibitors (cetuximab, erlotinib), leading to drug resistance in xenograft and spontaneous CRC models of KRAS-wild-type CRC. P. stomatis also abrogates BRAF inhibitor (vemurafenib) efficacy in BRAFV600E-mutant CRC xenografts. Thus, we identify P. stomatis as an oncogenic bacterium and a contributory factor for non-responsiveness to RTK inhibitors in CRC.

The genetic duet of concurrent RASAL1 and PTEN alterations promotes cancer aggressiveness by cooperatively activating the PI3K-AKT pathway

The significance of the prominent tumor suppressor gene for RAS protein activator-like 1 (RASAL1) could be better understood by combined genetic, clinical, and functional studies. Here, we investigated the oncogenic and clinical impacts of genetic alterations of RASAL1, particularly when coexisting with genetic alterations of the gene for phosphatase and tensin homolog (PTEN), in 9924 cancers of 33 types in the TCGA database. We found common concurrent genetic alterations of the two genes, which were cooperatively associated with activation of the phosphatidylinositol 3-kinase (PI3K)-AKT pathway, with cancer progression and mortality rates being 46.36% and 31.72% with concurrent gene alterations, versus 29.80% and 16.93% with neither gene alteration (HR 1.64, 95% CI 1.46-1.84 and 1.77, 95% CI 1.53-2.05), respectively. This was enhanced by additional tumor protein p53 (TP53) gene alterations, with cancer progression and mortality rates being 47.65% and 34.46% with coexisting RASAL1, PTEN, and TP53 alterations versus 25.30% and 13.11% with no alteration (HR 2.21, 95% CI 1.92-2.56 and 2.76, 95% CI 2.31-3.30), respectively. In the case of breast cancer, this genetic trio was associated with a triple-negative risk of 68.75% versus 3.83% with no genetic alteration (RR 17.94, 95% CI 9.60-33.51), consistent with the aggressive nature of triple-negative breast cancer. Mice with double knockouts of Rasal1 and Pten displayed robust Pi3k pathway activation, with the development of metastasizing malignancies, while single gene knockout resulted in only benign neoplasma. These results suggest that RASAL1, like PTEN, is a critical player in negatively regulating the PI3K-AKT pathway; defect in RASAL1 causes RAS activation, thus initiating the PI3K-AKT pathway signaling, which cannot terminate with concurrent PTEN defects. Thus, the unique concurrent RASAL1 and PTEN defects drive oncogenesis and cancer aggressiveness by cooperatively activating the PI3K-AKT pathway. This represents a robust genetic mechanism to promote human cancer.

Netrin signaling mediates survival of dormant epithelial ovarian cancer cells

Dormancy in cancer is a clinical state in which residual disease remains undetectable for a prolonged duration. At a cellular level, rare cancer cells cease proliferation and survive chemotherapy and disseminate disease. We created a suspension culture model of high-grade serous ovarian cancer (HGSOC) dormancy and devised a novel CRISPR screening approach to identify survival genes in this context. In combination with RNA-seq, we discovered the Netrin signaling pathway as critical to dormant HGSOC cell survival. We demonstrate that Netrin-1, -3, and its receptors are essential for low level ERK activation to promote survival, and that Netrin activation of ERK is unable to induce proliferation. Deletion of all UNC5 family receptors blocks Netrin signaling in HGSOC cells and compromises viability during the dormancy step of dissemination in xenograft assays. Furthermore, we demonstrate that Netrin-1 and -3 overexpression in HGSOC correlates with poor outcome. Specifically, our experiments reveal that Netrin overexpression elevates cell survival in dormant culture conditions and contributes to greater spread of disease in a xenograft model of abdominal dissemination. This study highlights Netrin signaling as a key mediator HGSOC cancer cell dormancy and metastasis.

Probing the Electrostatic Effects of H-Ras Tyrosine 32 Mutations on Intrinsic GTP Hydrolysis Using Vibrational Stark Effect Spectroscopy of a Thiocyanate Probe

The wildtype H-Ras protein functions as a molecular switch in a variety of cell signaling pathways, and mutations to key residues result in a constitutively active oncoprotein. However, there is some debate regarding the mechanism of the intrinsic GTPase activity of H-Ras. It has been hypothesized that ordered water molecules are coordinated at the active site by Q61, a highly transforming amino acid site, and Y32, a position that has not previously been investigated. Here, we examine the electrostatic contribution of the Y32 position to GTP hydrolysis by comparing the rate of GTP hydrolysis of Y32X mutants to the vibrational energy shift of each mutation measured by a nearby thiocyanate vibrational probe to estimate changes in the electrostatic environment caused by changes at the Y32 position. We further compared vibrational energy shifts for each mutation to the hydration potential of the respective side chain and demonstrated that Y32 is less critical for recruiting water molecules into the active site to promote hydrolysis than Q61. Our results show a clear interplay between a steric contribution from Y32 and an electrostatic contribution from Q61 that are both critical for intrinsic GTP hydrolysis.

Discovery of MK-1084: An Orally Bioavailable and Low-Dose KRASG12C Inhibitor

Oncogenic mutations in the RAS gene account for 30% of all human tumors; more than 60% of which present as KRAS mutations at the hotspot codon 12. After decades of intense pursuit, a covalent inhibition strategy has enabled selective targeting of this previously "undruggable" target. Herein, we disclose our journey toward the discovery of MK-1084, an orally bioavailable and low-dose KRASG12C covalent inhibitor currently in phase I clinical trials (NCT05067283). We leveraged structure-based drug design to identify a macrocyclic core structure, and hypothesis-driven optimization of biopharmaceutical properties to further improve metabolic stability and tolerability.

Glutathione‑degrading enzymes in the complex landscape of tumors (Review)

Glutathione (GSH)‑degrading enzymes are essential for starting the first stages of GSH degradation. These enzymes include extracellular γ‑glutamyl transpeptidase (GGT) and intracellular GSH‑specific γ‑glutamylcyclotransferase 1 (ChaC1) and 2. These enzymes are essential for cellular activities, such as immune response, differentiation, proliferation, homeostasis regulation and programmed cell death. Tumor tissue frequently exhibits abnormal expression of GSH‑degrading enzymes, which has a key impact on the development and spread of malignancies. The present review summarizes gene and protein structure, catalytic activity and regulation of GSH‑degrading enzymes, their vital roles in tumor development (including regulation of oxidative and endoplasmic reticulum stress, control of programmed cell death, promotion of inflammation and tumorigenesis and modulation of drug resistance in tumor cells) and potential role as diagnostic biomarkers and therapeutic targets.

Genetic and Molecular Biomarkers in Aggressive Pheochromocytomas and Paragangliomas

Pheochromocytomas and paragangliomas (PPGLs) are rare neoplasms producing catecholamines that occur as hereditary syndromes in 25-40% of cases. To date, PPGLs are no longer classified as benign and malignant tumors since any lesion could theoretically metastasize, even if it occurs only in a minority of cases (approximately 10-30%). Over the last decades, several attempts were made to develop a scoring system able to predict the risk of aggressive behavior at diagnosis, including the risk of metastases and disease recurrence; unfortunately, none of the available scores is able to accurately predict the risk of aggressive behavior, even including clinical, biochemical, and histopathological features. Thus, life-long follow-up is required in PPGL patients. Some recent studies focusing on genetic and molecular markers (involved in hypoxia regulation, gene transcription, cellular growth, differentiation, signaling pathways, and apoptosis) seem to indicate they are promising prognostic factors, even though their clinical significance needs to be further evaluated. The most involved pathways in PPGLs with aggressive behavior are represented by Krebs cycle alterations caused by succinate dehydrogenase subunits (SDHx), especially when caused by SDHB mutations, and by fumarate hydratase mutations that lead to the activation of hypoxia pathways and DNA hypermethylation, suggesting a common pathway in tumorigenesis. Conversely, PPGLs showing mutations in the kinase cascade (cluster 2) tend to display less aggressive behavior. Finally, establishing pathways of tumorigenesis is also fundamental to developing new drugs targeted to specific pathways and improving the survival of patients with metastatic disease. Unfortunately, the rarity of these tumors and the scarce number of cases enrolled in the available studies represents an obstacle to validating the role of molecular markers as reliable predictors of aggressiveness.

Assessment of KRASG12C inhibitors for colorectal cancer

Colorectal cancer (CRC) is a highly prevalent and lethal cancer worldwide. Approximately 45% of CRC patients harbor a gain-in-function mutation in KRAS. KRAS is the most frequently mutated oncogene accounting for approximately 25% of all human cancers. Gene mutations in KRAS cause constitutive activation of the KRAS protein and MAPK/AKT signaling, resulting in unregulated proliferation and survival of cancer cells and other aspects of malignant transformation, progression, and metastasis. While KRAS has long been considered undruggable, the FDA recently approved two direct acting KRAS inhibitors, Sotorasib and Adagrasib, that covalently bind and inactivate KRASG12C. Both drugs showed efficacy for patients with non-small cell lung cancer (NSCLC) diagnosed with a KRASG12C mutation, but for reasons not well understood, were considerably less efficacious for CRC patients diagnosed with the same mutation. Thus, it is imperative to understand the basis for resistance to KRASG12C inhibitors, which will likely be the same limitations for other mutant specific KRAS inhibitors in development. This review provides an update on clinical trials involving CRC patients treated with KRASG12C inhibitors as a monotherapy or combined with other drugs. Mechanisms that contribute to resistance to KRASG12C inhibitors and the development of novel RAS inhibitors with potential to escape such mechanisms of resistance are also discussed.

Phosphine-Catalyzed Synthesis and Cytotoxic Evaluation of Michael Adducts of the Sesquiterpene Lactone Arglabin

A general method for chemo- and diastereoselective modification of anticancer natural product arglabin with nitrogen- and carbon-centered pronucleophiles under the influence of nucleophilic phosphine catalysts was developed. The locked s-cis-geometry of α-methylene-γ-butyrolactone moiety of arglabin favors for the additional stabilization of the zwitterionic intermediate by electrostatic interaction between phosphonium and enolate oxygen centers, leading to the unprecedentedly high efficiency of the phosphine-catalyzed Michael additions to this sesquiterpene lactone. Using n-Bu3P as the catalyst, pyrazole, phthalimide, 2-oxazolidinone, 4-quinazolinone, uracil, thymine, cytosine, and adenine adducts of arglabin were obtained. The n-Bu3P-catalyzed reaction of arglabin with active methylene compounds resulted in the predominant formation of bisadducts bearing a new quaternary carbon center. All synthesized Michael adducts and previously obtained phosphorylated arglabin derivatives were evaluated in vitro against eleven cancer and two normal cell lines, and the results were compared to those of natural arglabin and its dimethylamino hydrochloride salt currently used as anticancer drugs. 2-Oxazolidinone, uracil, diethyl malonate, dibenzyl phosphonate, and diethyl cyanomethylphosphonate derivatives of arglabin exhibited more potent antiproliferative activity towards several cancer cell lines and lower cytotoxicity towards normal cell lines in comparison to the reference compounds, indicating the feasibility of the developed methodology for the design of novel anticancer drugs with better therapeutic potential.

Current perspectives of KRAS in non-small cell lung cancer

NSCLC has a diverse genomic background with mutations in key proto-oncogenic drivers including Kirsten rat sarcoma (KRAS) and epidermal growth factor receptor (EGFR). Roughly 40% of adenocarcinoma harbor Kras activating mutations regardless of smoking history. Most KRAS mutations are located at G12, which include G12C (roughly 40%), G12V (roughly 20%), and G12D (roughly 15%). KRAS mutated NSCLC have higher tumor mutational burden and some have increased PD-1 expression, which has resulted in better responses to immunotherapy than other oncogenes. While initial treatment for metastatic NSCLC still relies on chemo-immunotherapy, directly targeting KRAS has proven to be efficacious in treating patients with KRAS mutated metastatic NSCLC. To date, two G12C inhibitors have been FDA-approved, namely sotorasib and adagrasib. In this review, we summarize the different drug combinations used to target KRAS G12c, upcoming G12D inhibitors and novel therapies targeting KRAS.

Gene regulatory networks in disease and ageing

The precise control of gene expression is required for the maintenance of cellular homeostasis and proper cellular function, and the declining control of gene expression with age is considered a major contributor to age-associated changes in cellular physiology and disease. The coordination of gene expression can be represented through models of the molecular interactions that govern gene expression levels, so-called gene regulatory networks. Gene regulatory networks can represent interactions that occur through signal transduction, those that involve regulatory transcription factors, or statistical models of gene-gene relationships based on the premise that certain sets of genes tend to be coexpressed across a range of conditions and cell types. Advances in experimental and computational technologies have enabled the inference of these networks on an unprecedented scale and at unprecedented precision. Here, we delineate different types of gene regulatory networks and their cell-biological interpretation. We describe methods for inferring such networks from large-scale, multi-omics datasets and present applications that have aided our understanding of cellular ageing and disease mechanisms.

Oncogenes and tumor suppressor genes: functions and roles in cancers

Cancer, being the most formidable ailment, has had a profound impact on the human health. The disease is primarily associated with genetic mutations that impact oncogenes and tumor suppressor genes (TSGs). Recently, growing evidence have shown that X-linked TSGs have specific role in cancer progression and metastasis as well. Interestingly, our genome harbors around substantial portion of genes that function as tumor suppressors, and the X chromosome alone harbors a considerable number of TSGs. The scenario becomes even more compelling as X-linked TSGs are adaptive to key epigenetic processes such as X chromosome inactivation. Therefore, delineating the new paradigm related to X-linked TSGs, for instance, their crosstalk with autosome and involvement in cancer initiation, progression, and metastasis becomes utmost importance. Considering this, herein, we present a comprehensive discussion of X-linked TSG dysregulation in various cancers as a consequence of genetic variations and epigenetic alterations. In addition, the dynamic role of X-linked TSGs in sex chromosome-autosome crosstalk in cancer genome remodeling is being explored thoroughly. Besides, the functional roles of ncRNAs, role of X-linked TSG in immunomodulation and in gender-based cancer disparities has also been highlighted. Overall, the focal idea of the present article is to recapitulate the findings on X-linked TSG regulation in the cancer landscape and to redefine their role toward improving cancer treatment strategies.

Tumor biomarkers for diagnosis, prognosis and targeted therapy

Tumor biomarkers, the substances which are produced by tumors or the body's responses to tumors during tumorigenesis and progression, have been demonstrated to possess critical and encouraging value in screening and early diagnosis, prognosis prediction, recurrence detection, and therapeutic efficacy monitoring of cancers. Over the past decades, continuous progress has been made in exploring and discovering novel, sensitive, specific, and accurate tumor biomarkers, which has significantly promoted personalized medicine and improved the outcomes of cancer patients, especially advances in molecular biology technologies developed for the detection of tumor biomarkers. Herein, we summarize the discovery and development of tumor biomarkers, including the history of tumor biomarkers, the conventional and innovative technologies used for biomarker discovery and detection, the classification of tumor biomarkers based on tissue origins, and the application of tumor biomarkers in clinical cancer management. In particular, we highlight the recent advancements in biomarker-based anticancer-targeted therapies which are emerging as breakthroughs and promising cancer therapeutic strategies. We also discuss limitations and challenges that need to be addressed and provide insights and perspectives to turn challenges into opportunities in this field. Collectively, the discovery and application of multiple tumor biomarkers emphasized in this review may provide guidance on improved precision medicine, broaden horizons in future research directions, and expedite the clinical classification of cancer patients according to their molecular biomarkers rather than organs of origin.

Evaluation of KRAS inhibitor-directed therapies for pancreatic cancer treatment

Despite significant advancements in the treatment of other cancers, pancreatic ductal adenocarcinoma (PDAC) remains one of the world's deadliest cancers. More than 90% of PDAC patients harbor a Kirsten rat sarcoma (KRAS) gene mutation. Although the clinical potential of anti-KRAS therapies has long been realized, all initial efforts to target KRAS were unsuccessful. However, with the recent development of a new generation of KRAS-targeting drugs, multiple KRAS-targeted treatment options for patients with PDAC have entered clinical trials. In this review, we provide an overview of current standard of care treatment, describe RAS signaling and the relevance of KRAS mutations, and discuss RAS isoform- and mutation-specific differences. We also evaluate the clinical efficacy and safety of mutation-selective and multi-selective inhibitors, in the context of PDAC. We then provide a comparison of clinically relevant KRAS inhibitors to second-line PDAC treatment options. Finally, we discuss putative resistance mechanisms that may limit the clinical effectiveness of KRAS-targeted therapies and provide a brief overview of promising therapeutic approaches in development that are focused on mitigating these resistance mechanisms.

Targeting KRASG12C in Non-Small-Cell Lung Cancer: Current Standards and Developments

Among the most common molecular alterations detected in non-small-cell lung cancer (NSCLC) are mutations in Kristen Rat Sarcoma viral oncogene homolog (KRAS). KRAS mutant NSCLC is a heterogenous group of diseases, different from other oncogene-driven tumors in terms of biology and response to therapies. Despite efforts to develop drugs aimed at inhibiting KRAS or its signaling pathways, KRAS had remained undruggable for decades. The discovery of a small pocket in the binding switch II region of KRASG12C has revolutionized the treatment of KRASG12C-mutated NSCLC patients. Sotorasib and adagrasib, direct KRASG12C inhibitors, have been approved by the US Food and Drug Administration (FDA) and other regulatory agencies for patients with previously treated KRASG12C-mutated NSCLC, and these advances have become practice changing. However, first-line treatment in KRASG12C-mutated NSCLC does not differ from NSCLC without actionable driver genomic alterations. Treatment with KRASG12C inhibitors is not curative and patients develop progressive disease, so understanding associated mechanisms of drug resistance is key. New KRASG12C inhibitors and several combination therapy strategies, including with immune checkpoint inhibitors, are being studied in clinical trials. The aim of this review is to explore the clinical impact of KRAS, and outline different treatment approaches, focusing on the novel treatment of KRASG12C-mutated NSCLC.

Identification and affinity enhancement of T-cell receptor targeting a KRASG12V cancer neoantigen

Neoantigens derived from somatic mutations in Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS), the most frequently mutated oncogene, represent promising targets for cancer immunotherapy. Recent research highlights the potential role of human leukocyte antigen (HLA) allele A*11:01 in presenting these altered KRAS variants to the immune system. In this study, we successfully generate and identify murine T-cell receptors (TCRs) that specifically recognize KRAS8-16G12V from three predicted high affinity peptides. By determining the structure of the tumor-specific 4TCR2 bound to KRASG12V-HLA-A*11:01, we conduct structure-based design to create and evaluate TCR variants with markedly enhanced affinity, up to 15.8-fold. This high-affinity TCR mutant, which involved only two amino acid substitutions, display minimal conformational alterations while maintaining a high degree of specificity for the KRASG12V peptide. Our research unveils the molecular mechanisms governing TCR recognition towards KRASG12V neoantigen and yields a range of affinity-enhanced TCR mutants with significant potential for immunotherapy strategies targeting tumors harboring the KRASG12V mutation.

Overexpression of SYNGAP1 suppresses the proliferation of rectal adenocarcinoma via Wnt/β-Catenin signaling pathway

Rectal adenocarcinoma (READ) is a common malignant tumor of the digestive tract. Growing studies have confirmed Ras GTPase-activating proteins are involved in the progression of several tumors. This study aimed to explore the expression and function of Ras GTPase-activating proteins in READ. In this study, we analyzed RNA sequencing data from 165 patients with READ and 789 normal tissue samples, identifying 5603 differentially expressed genes (DEGs), including 2937 upregulated genes and 2666 downregulated genes. Moreover, we also identified two dysregulated genes, RASA4 and SYNGAP1, among six Ras GTPase-activating proteins. High NF1 expression was associated with longer overall survival, while high SYNGAP1 expression showed a trend towards extended overall survival. Further analysis revealed the mutation frequency and copy number variations of Ras GTPase-activating proteins in various cancer samples. Additionally, DNA methylation analysis demonstrated a negative correlation between DNA methylation of Ras GTPase-activating proteins and their expression. Moreover, among Ras GTPase-activating proteins, we focused on SYNGAP1, and experimental validation confirmed that the overexpression of SYNGAP1 in READ significantly suppressed READ cell proliferation and increased apoptosis via regulating the Wnt/β-Catenin signaling pathway. These findings underscored the potential significance of SYNGAP1 in READ and provide new insights for further research and treatment.

Somatic Mutations in Surgically Treated Colorectal Liver Metastases: An Overview

Colorectal cancer is the second most common cause of cancer death in the United States, and up to half of patients develop colorectal liver metastases (CRLMs). Notably, somatic genetic mutations, such as mutations in RAS, BRAF, mismatch repair (MMR) genes, TP53, and SMAD4, have been shown to play a prognostic role in patients with CRLM. This review summarizes and appraises the current literature regarding the most relevant somatic mutations in surgically treated CRLM by not only reviewing representative studies, but also providing recommendations for areas of future research. In addition, advancements in genetic testing and an increasing emphasis on precision medicine have led to a more nuanced understanding of these mutations; thus, more granular data for each mutation are reviewed when available. Importantly, such knowledge can pave the way for precision medicine with the ultimate goal of improving patient outcomes.

Natural Polymer-Based Nanogel for pH-Responsive Delivery of Sorafenib Tosylate in Hemangiosarcoma

Smart nanomedicinal treatment for cancer manifests a solubility challenge with inherent nanoscale size and nonspecific release with stimuli-responsive potential. This is the limelight in novel chemotherapy to pursue physiochemical differences between the tumor microenvironment (TME) and normal cells, which introduces active groups of nanocarriers responding to various stimuli, endowing them with concise responses to various tumor-related signals. The nanogels were successfully prepared by a modified solvent evaporation technique. Nine batches were formulated by changing the chitosan concentration (12, 14, 16 mg/ml) and sonication time (5, 10, 15 min). The formulations were optimized for particle size and zeta potential with high percent entrapment efficiency (%EE) through Central Composite Design software. The optimized batch F7 had a 182-nm size and high zeta potential (64.5 mV) with 98% EE. The drug release of F7 was higher at pH 6 (97.556%) than at pH 7.4 (45.113%). The pharmacokinetic study shows that the release follows the Hixon plot model (R2 = 0.9334) that shifts to zero order (R2 = 0.9149). The nanogel F7 was observed for stability and showed an absence of color change, phase separation, and opacity for 6 months. In the present study, the pH difference between cancer cells and normal cells is the key point of the smart nanogel. This study is promising but challenging depending on the in vivo study. The nanogel was successfully prepared and evaluated for pH-responsive release. As hemangiosarcoma commonly occurs in dogs, this formulation helps to limit the difficulties with administration.

Biophysical and Biochemical Characterization of Structurally Diverse Small Molecule Hits for KRAS Inhibition

We describe six compounds as early hits for the development of direct inhibitors of KRAS, an important anticancer drug target. We show that these compounds bind to KRAS with affinities in the low micromolar range and exert different effects on its interactions with binding partners. Some of the compounds exhibit selective binding to the activated form of KRAS and inhibit signal transduction through both the MAPK or the phosphatidylinositide 3-kinase PI3K-protein kinase B (AKT) pathway in cells expressing mutant KRAS. Most inhibit intrinsic and/or SOS-mediated KRAS activation while others inhibit RAS-effector interaction. We propose these compounds as starting points for the development of non-covalent allosteric KRAS inhibitors.

Concurrent targeting of GSK3 and MEK as a therapeutic strategy to treat pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies worldwide. However, drug discovery for PDAC treatment has proven complicated, leading to stagnant therapeutic outcomes. Here, we identify Glycogen synthase kinase 3 (GSK3) as a therapeutic target through a whole-body genetic screening utilizing a '4-hit' Drosophila model mimicking the PDAC genotype. Reducing the gene dosage of GSK3 in a whole-body manner or knocking down GSK3 specifically in transformed cells suppressed 4-hit fly lethality, similar to Mitogen-activated protein kinase kinase (MEK), the therapeutic target in PDAC we have recently reported. Consistently, a combination of the GSK3 inhibitor CHIR99021 and the MEK inhibitor trametinib suppressed the phosphorylation of Polo-like kinase 1 (PLK1) as well as the growth of orthotopic human PDAC xenografts in mice. Additionally, reducing PLK1 genetically in 4-hit flies rescued their lethality. Our results reveal a therapeutic vulnerability in PDAC that offers a treatment opportunity for patients by inhibiting multiple targets.

EGFR degraders in non-small-cell lung cancer: Breakthrough and unresolved issue

The epidermal growth factor receptor (EGFR) has been well validated as a therapeutic target for anticancer drug discovery. Osimertinib has become the first globally accessible third-generation EGFR inhibitor, representing one of the most advanced developments in non-small-cell lung cancer (NSCLC) therapy. However, a tertiary Cys797 to Ser797 (C797S) point mutation has hampered osimertinib treatment in patients with advanced EGFR-mutated NSCLC. Several classes of fourth-generation EGFR inhibitors were consequently discovered with the aim of overcoming the EGFRC797S mutation-mediated resistance. However, no clinical efficacy data of the fourth-generation EGFR inhibitors were reported to date, and EGFRC797S mutation-mediated resistance remains an "unmet clinical need." Proteolysis-targeting chimeric molecules (PROTACs) obtained from EGFR-TKIs have been developed to target drug resistance EGFR in NSCLC. Some PROTACs are from nature products. These degraders compared with EGFR inhibitors showed better efficiency in their cellular potency, inhibition, and toxicity profiles. In this review, we first introduce the structural properties of EGFR, the resistance, and mutations of EGFR, and then mainly focus on the recent advances of EGFR-targeting degraders along with its advantages and outstanding challenges.

Exploiting the therapeutic implications of KRAS inhibition on tumor immunity

Over the past decade, RAS oncogenic proteins have transitioned from being deemed undruggable to having two clinically approved drugs, with several more in advanced stages of development. Despite the initial benefit of KRAS-G12C inhibitors for patients with tumors harboring this mutation, the rapid emergence of drug resistance underscores the urgent need to synergize these inhibitors with other therapeutic approaches to improve outcomes. RAS mutant tumor cells can create an immunosuppressive tumor microenvironment (TME), suggesting an increased susceptibility to immunotherapies following RAS inhibition. This provides a rationale for combining RAS inhibitory drugs with immune checkpoint blockade (ICB). However, achieving this synergy in the clinical setting has proven challenging. Here, we explore how understanding the impact of RAS mutant tumor cells on the TME can guide innovative approaches to combining RAS inhibition with immunotherapies, review progress in both pre-clinical and clinical stages, and discuss challenges and future directions.

Design, synthesis, and evaluation of dual EGFR/AURKB inhibitors as anticancer agents for non-small cell lung cancer

The epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are first-line agents for mutant EGFR-positive (mEGFR+) NSCLC. However, secondary resistant mutations develop following therapy that prevent EGFR-TKI binding. The EGFR-TKIs are rendered ineffective in NSCLC expressing EGFR resistant mutations (rmEGFR+). Mutations in Kirsten rat sarcoma virus protein (mKRAS) support persistent signaling downstream of EGFR regardless of EGFR-TKI earlier in the signaling cascade. The EGFR-TKIs are ineffective in mKRAS+ NSCLC. Thus, newer anticancer agents are needed for rmEGFR+ and mKRAS+ NSCLC. Aurora kinase B (AURKB) is a mitosis related kinase that is overexpressed in NSCLC and supports cancer cell proliferation and survival. Literature reports have suggested that AURKB inhibitors if given concurrently with an EGFR-TKI could overcome EGFR-TKI resistance in mKRAS+ NSCLC and rmEGFR + NSCLC, and showed improved anticancer effects compared to current single-targeted EGFR-TKIs. Molecular modeling was used to identify similarities between the kinase pockets of EGFR and AURKB. An overlap was observed for the inactive conformation of EGFR and the active conformation of AURKB. Compounds 3-7 were synthesized as dual EGFR/AURKB inhibitors for mKRAS+ and rmEGFR+ NSCLC. Compounds 5, 6 and 7 were identified as dual EGFR/AURKB inhibitors. Compound 5 demonstrated modest micromolar inhibition of rmEGFR+ NSCLC. All investigated compounds showed moderate inhibition of mKRAS+ NSCLC cells. Compound 7 demonstrated single-digit micromolar inhibition of mKRAS+ NSCLC.

Regulation of Ras p21 and RalA GTPases activity by quinine in mammary epithelial cells

Quinine, a bitter compound, can act as an agonist to activate the family of bitter taste G protein-coupled receptor family of proteins. Previous work from our laboratory has demonstrated that quinine causes activation of RalA, a Ras p21-related small G protein. Ral proteins can be activated directly or indirectly through an alternative pathway that requires Ras p21 activation resulting in the recruitment of RalGDS, a guanine nucleotide exchange factor for Ral. Using normal mammary epithelial (MCF-10A) and non-invasive mammary epithelial (MCF-7) cell lines, we investigated the effect of quinine in regulating Ras p21 and RalA activity. Results showed that in the presence of quinine, Ras p21 is activated in both MCF-10A and MCF-7 cells; however, RalA was inhibited in MCF-10A cells, and no effect was observed in the case of MCF-7 cells. MAP kinase, a downstream effector for Ras p21, was activated in both MCF-10A and MCF-7 cells. Western blot analysis confirmed the expression of RalGDS in MCF-10A cells and MCF-7 cells. The expression of RalGDS was higher in MCF-10A cells in comparison to the MCF-7 cells. Although RalGDS was detected in MCF-10A and MCF-7 cells, it did not result in RalA activation upon Ras p21 activation with quinine suggesting that the Ras p21-RalGDS-RalA pathway is not active in the MCF-10A cells. The inhibition of RalA activity in MCF-10A cells due to quinine could be as a result of a direct effect of this bitter compound on RalA. Protein modeling and ligand docking analysis demonstrated that quinine can interact with RalA through the R79 amino acid, which is located in the switch II region loop of the RalA protein. It is possible that quinine causes a conformational change that results in the inhibition of RalA activation even though RalGDS is present in the cell. More studies are needed to elucidate the mechanism(s) that regulate Ral activity in mammary epithelial cells.

Prognostic and predictive biomarkers in non-small cell lung carcinoma

Lung cancer is the most common cause of cancer-related deaths globally, with the highest mortality rates among both men and women. Most lung cancers are diagnosed at late stages, necessitating systemic therapy. Modern clinical management of lung cancer relies heavily upon application of biomarkers, which guide the selection of systemic treatment. Here, we provide an overview of currently approved and emerging biomarkers of non-small cell lung cancer (NSCLC), including EGFR, ALK, ROS1, RET, NTRK1-3, KRAS, BRAF, MET, ERBB2/HER2, NRG1, PD-L1, TROP2, and CEACAM5. For practical purposes, we divide these biomarkers into genomic and protein markers, based on the tested substrate. We review the biology and epidemiology of the genomic and proteomic biomarkers, discuss optimal diagnostic assays for their detection, and highlight their contribution to the contemporary clinical management of NSCLC.

Regulatory role of miRNAs in nasopharyngeal cancer involving PTEN/PI3K/AKT, TGFβ/SMAD, RAS/MAPK, Wnt/β-catenin and pRB-E2F signaling pathways: A review

MicroRNAs (miRNA) are small and conserved noncoding RNA molecules that regulate gene expression at the posttranscriptional level. These groups of RNAs are crucial in various cellular processes, especially in mediating disease pathogenesis, particularly cancer. The dysregulation of miRNAs was reported in many cancer types, including nasopharyngeal cancer (NPC), which is a malignant tumor of the nasopharynx. In this review, miRNAs involvement in crucial signaling pathways associated with NPC such as PTEN/PI3K/AKT, TGFβ/SMAD, RAS/MAPK, Wnt/β-catenin and pRB-E2F was investigated. miRNAs could function as tumor suppressor-miR or onco-miR in NPC profoundly influenced cell cycle, apoptosis, proliferation, migration, and metastasis. This comprehensive review of current literature provided a thorough profile of miRNAs and their interplay with the aforementioned signaling pathways in NPC. Understanding these molecular interactions could remarkably impact the diagnosis, prognosis, and therapeutic strategies for NPC.

Altered hormone expression induced genetic changes leads to breast cancer

PURPOSE OF REVIEW

Breast cancer ranks first among gynecological cancer in India. It is associated with urbanization, changes in lifestyle and obesity. Hormones also play a crucial role in the development of breast cancer. Steroid hormones play critical role in development of breast cancer.

RECENT FINDING

Breast cancer is caused due to alteration in different hormone expressions leading to genetic instability. Loss or gains of functions due to genetic instability were associated with the alterations in housekeeping genes. Up-regulation in c-myc, signal transducer and activator of transcription (STAT), CREB-regulated transcription coactivator (CRTC), and eukaryotic translation initiation factor 4E (eIF4E) may cause the development of breast cancer. Peptide hormones are commonly following the phosphoinositide 3-kinases (PI3K) pathway for activation of cell cycle causing uncontrolled proliferation. Although steroid hormones are following the Ras/Raf/mitogen-activated protein kinase (MEK) pathway, their hyper-activation of these pathways causes extracellular-signal-regulated kinase (ERK) and MAPK activation, leading to carcinogenesis.

SUMMARY

Alteration in cell cycle proteins, oncogenes, tumor suppressor genes, transcription and translation factors lead to breast cancer. Apoptosis plays a vital role in the elimination of abnormal cells but failure in any of these apoptotic pathways may cause tumorigenesis. Hence, a complex interplay of hormonal and genetic factors is required to maintain homeostasis in breast cells. Imbalance in homeostasis of these hormone and genes may lead to breast cancer.

Contemporary Surgical Management of Colorectal Liver Metastases

Colorectal cancer is the third most common cancer in the United States and the second most common cause of cancer-related death. Approximately 20-30% of patients will develop hepatic metastasis in the form of synchronous or metachronous disease. The treatment of colorectal liver metastasis (CRLM) has evolved into a multidisciplinary approach, with chemotherapy and a variety of locoregional treatments, such as ablation and portal vein embolization, playing a crucial role. However, resection remains a core tenet of management, serving as the gold standard for a curative-intent therapy. As such, the input of a dedicated hepatobiliary surgeon is paramount for appropriate patient selection and choice of surgical approach, as significant advances in the field have made management decisions extremely nuanced and complex. We herein aim to review the contemporary surgical management of colorectal liver metastasis with respect to both perioperative and operative considerations.

Fusobacterium nucleatum promotes tumor progression in KRAS p.G12D-mutant colorectal cancer by binding to DHX15

Fusobacterium nucleatum (F. nucleatum) promotes intestinal tumor growth and its relative abundance varies greatly among patients with CRC, suggesting the presence of unknown, individual-specific effectors in F. nucleatum-dependent carcinogenesis. Here, we identify that F. nucleatum is enriched preferentially in KRAS p.G12D mutant CRC tumor tissues and contributes to colorectal tumorigenesis in Villin-Cre/KrasG12D+/- mice. Additionally, Parabacteroides distasonis (P. distasonis) competes with F. nucleatum in the G12D mouse model and human CRC tissues with the KRAS mutation. Orally gavaged P. distasonis in mice alleviates the F. nucleatum-dependent CRC progression. F. nucleatum invades intestinal epithelial cells and binds to DHX15, a protein of RNA helicase family expressed on CRC tumor cells, mechanistically involving ERK/STAT3 signaling. Knock out of Dhx15 in Villin-Cre/KrasG12D+/- mice attenuates the CRC phenotype. These findings reveal that the oncogenic effect of F. nucleatum depends on somatic genetics and gut microbial ecology and indicate that personalized modulation of the gut microbiota may provide a more targeted strategy for CRC treatment.

Distinctive mesenchymal-like neurofibroma stem cells shape NF1 clinical phenotypes controlled by BDNF microenvironment

BACKGROUND

Neurofibroma type I (NF1) often presents with multiple clinical phenotypes due to mutations of NF1 gene. The aim of this study was to determine the phenotypic and therapeutic relevance of tumor microenvironment in NF1 patients.

METHODS

Tumor stem cells (TSCs) from NF1 were isolated and cultured using fluorescence activated cell sorting (FACS) and colony formation experiments. Then, flow cytometry was used to detect the surface markers, osteogenic and adipogenic differentiation were performed as well. Its tumorigenesis ability was confirmed by subcutaneous tumorigenesis in nude mice. Immunohistochemical staining was performed on neurofibroma tissues from the head and trunk with different phenotypes. The expression of BDNF in neurofibroma tissues was detected by Elisa and immunohistochemical staining. Western Blotting was used to detect the expression of p38 MAPK pathway in TSCs. The effect of BDNF neutralizing antibody on the tumorigenesis of TSCs was observed.

RESULTS

Herein, we advocate that NF1 contain a new subgroup of mesenchymal-like neurofibroma stem cells (MNSCs). Such colony-forming MNSCs preserved self-renewal, multiple differentiation and tumorigenic capabilities. More interestingly, the MNSCs isolated from neurofibroma tissues of the same patient with different phenotypes presented site-specific capabilities. Moreover, different levels of brain-derived neurotrophic factor (BDNF) in neurofibroma tissues can impact the MNSCs by activating the TrkB/p38 MAPK pathway. Systemic administration of BDNF neutralizing antibodies inhibited MNSCs' characteristics.

CONCLUSIONS

We demonstrated that BDNF can modulate MNSCs and thereby controlling different tumor phenotypes between the head and trunk regions. Application of BDNF neutralizing antibodies may inhibit p38 MAPK pathway, therefore providing a promising strategy for managing NF1.

Exploring Retrograde Trafficking: Mechanisms and Consequences in Cancer and Disease

Retrograde trafficking (RT) orchestrates the intracellular movement of cargo from the plasma membrane, endosomes, Golgi or endoplasmic reticulum (ER)-Golgi intermediate compartment (ERGIC) in an inward/ER-directed manner. RT works as the opposing movement to anterograde trafficking (outward secretion), and the two work together to maintain cellular homeostasis. This is achieved through maintaining cell polarity, retrieving proteins responsible for anterograde trafficking and redirecting proteins that become mis-localised. However, aberrant RT can alter the correct location of key proteins, and thus inhibit or indeed change their canonical function, potentially causing disease. This review highlights the recent advances in the understanding of how upregulation, downregulation or hijacking of RT impacts the localisation of key proteins in cancer and disease to drive progression. Cargoes impacted by aberrant RT are varied amongst maladies including neurodegenerative diseases, autoimmune diseases, bacterial and viral infections (including SARS-CoV-2), and cancer. As we explore the intricacies of RT, it becomes increasingly apparent that it holds significant potential as a target for future therapies to offer more effective interventions in a wide range of pathological conditions.

Revealing the mechanism of action of a first-in-class covalent inhibitor of KRASG12C (ON) and other functional properties of oncogenic KRAS by 31P NMR

Individual oncogenic KRAS mutants confer distinct differences in biochemical properties and signaling for reasons that are not well understood. KRAS activity is closely coupled to protein dynamics and is regulated through two interconverting conformations: state 1 (inactive, effector binding deficient) and state 2 (active, effector binding enabled). Here, we use 31P NMR to delineate the differences in state 1 and state 2 populations present in WT and common KRAS oncogenic mutants (G12C, G12D, G12V, G13D, and Q61L) bound to its natural substrate GTP or a commonly used nonhydrolyzable analog GppNHp (guanosine-5'-[(β,γ)-imido] triphosphate). Our results show that GppNHp-bound proteins exhibit significant state 1 population, whereas GTP-bound KRAS is primarily (90% or more) in state 2 conformation. This observation suggests that the predominance of state 1 shown here and in other studies is related to GppNHp and is most likely nonexistent in cells. We characterize the impact of this differential conformational equilibrium of oncogenic KRAS on RAF1 kinase effector RAS-binding domain and intrinsic hydrolysis. Through a KRAS G12C drug discovery, we have identified a novel small-molecule inhibitor, BBO-8956, which is effective against both GDP- and GTP-bound KRAS G12C. We show that binding of this inhibitor significantly perturbs state 1-state 2 equilibrium and induces an inactive state 1 conformation in GTP-bound KRAS G12C. In the presence of BBO-8956, RAF1-RAS-binding domain is unable to induce a signaling competent state 2 conformation within the ternary complex, demonstrating the mechanism of action for this novel and active-conformation inhibitor.

Systematic pan-cancer analysis of RNF186 with potential implications in progression and prognosis in human cancer

AIMS

Cancer remains a significant global public health issue. There is growing proof that Ring Finger Protein 186 (RNF186) may play a function in pan-cancer, however, this has not yet been thoroughly determined. This study aims to analyze RNF186 with potential implications in progression and prognosis in human cancer.

MATERIALS AND METHODS

A comprehensive bioinformatics approaches combined with experimental verification were used across 33 types of cancers in this study to conduct a pan-cancer investigation of RNF186 from the perspectives of gene expression, prognosis, genomic alterations, immunological markers, gene set, and function.

KEY FINDINGS

RNF186 is a valuable prognostic biomarker in several cancer types, especially breast invasive carcinoma (BRCA) and uterine corpus endometrial carcinoma (UCEC). The levels of RNF186 promoter methylation and genetic alterations may be responsible for some cancers' abnormal expression. Furthermore, RNF186 expression was determined to be associated with immune checkpoint genes. Analysis of RNF186-related genes revealed that proteasome and PI3K-AKT signaling pathway were primarily involved in the cellular function of RNF186. Additionally, our research first confirmed that RNF186 may function as an oncogene and contribute to cancer proliferation, migration and invasion in UCEC. In contrast, RNF186 may play an inhibitory role in BRCA progression. This function depends on the ligase activity of RNF186.

SIGNIFICANCE

This study suggests that RNF186 is a novel critical target for tumor progression in BRCA and UCEC. It reveals that RNF186 may be associated with tumor immunotherapy, which may provide an effective predictive evaluation of the prognosis of immunotherapy.

Conformational States of the GDP- and GTP-Bound HRAS Affected by A59E and K117R: An Exploration from Gaussian Accelerated Molecular Dynamics

The HRAS protein is considered a critical target for drug development in cancers. It is vital for effective drug development to understand the effects of mutations on the binding of GTP and GDP to HRAS. We conducted Gaussian accelerated molecular dynamics (GaMD) simulations and free energy landscape (FEL) calculations to investigate the impacts of two mutations (A59E and K117R) on GTP and GDP binding and the conformational states of the switch domain. Our findings demonstrate that these mutations not only modify the flexibility of the switch domains, but also affect the correlated motions of these domains. Furthermore, the mutations significantly disrupt the dynamic behavior of the switch domains, leading to a conformational change in HRAS. Additionally, these mutations significantly impact the switch domain's interactions, including their hydrogen bonding with ligands and electrostatic interactions with magnesium ions. Since the switch domains are crucial for the binding of HRAS to effectors, any alterations in their interactions or conformational states will undoubtedly disrupt the activity of HRAS. This research provides valuable information for the design of drugs targeting HRAS.

Design, Synthesis, and Biological Evaluation of Potent and Selective PROTAC Degraders of Oncogenic KRASG12D

KRASG12D, the most frequent KRAS oncogenic mutation, is a promising target for cancer therapy. Herein, we report the design, synthesis, and biological evaluation of a series of KRASG12D PROTACs by connecting the analogues of MRTX1133 and the VHL ligand. Structural modifications of the linker moiety and KRAS inhibitor part suggested a critical role of membrane permeability in the degradation activity of the KRASG12D PROTACs. Mechanism studies with the representative compound 8o demonstrated that the potent, rapid, and selective degradation of KRASG12D induced by 8o was via a VHL- and proteasome-dependent manner. This compound selectively and potently suppressed the growth of multiple KRASG12D mutant cancer cells, displayed favorable pharmacokinetic and pharmacodynamic properties in mice, and showed significant antitumor efficacy in the AsPC-1 xenograft mouse model. Further optimization of 8o appears to be promising for the development of a new chemotherapy for KRASG12D-driven cancers as the complementary therapeutic strategy to KRAS inhibition.

Incorporating Novel Technologies in Precision Oncology for Colorectal Cancer: Advancing Personalized Medicine

Colorectal cancer (CRC) is one of the most heterogeneous and deadly diseases, with a global incidence of 1.5 million cases per year. Genomics has revolutionized the clinical management of CRC by enabling comprehensive molecular profiling of cancer. However, a deeper understanding of the molecular factors is needed to identify new prognostic and predictive markers that can assist in designing more effective therapeutic regimens for the improved management of CRC. Recent breakthroughs in single-cell analysis have identified new cell subtypes that play a critical role in tumor progression and could serve as potential therapeutic targets. Spatial analysis of the transcriptome and proteome holds the key to unlocking pathogenic cellular interactions, while liquid biopsy profiling of molecular variables from serum holds great potential for monitoring therapy resistance. Furthermore, gene expression signatures from various pathways have emerged as promising prognostic indicators in colorectal cancer and have the potential to enhance the development of equitable medicine. The advancement of these technologies for identifying new markers, particularly in the domain of predictive and personalized medicine, has the potential to improve the management of patients with CRC. Further investigations utilizing similar methods could uncover molecular subtypes specific to emerging therapies, potentially strengthening the development of personalized medicine for CRC patients.

Hedgehog signalling is involved in acquired resistance to KRASG12C inhibitors in lung cancer cells

Although KRASG12C inhibitors have shown promising activity in lung adenocarcinomas harbouring KRASG12C, acquired resistance to these therapies eventually occurs in most patients. Re-expression of KRAS is thought to be one of the main causes of acquired resistance. However, the mechanism through which cancer cells re-express KRAS is not fully understood. Here, we report that the Hedgehog signal is induced by KRASG12C inhibitors and mediates KRAS re-expression in cancer cells treated with a KRASG12C inhibitor. Further, KRASG12C inhibitors induced the formation of primary cilia and activated the Hedgehog-GLI-1 pathway. GLI-1 binds to the KRAS promoter region, enhancing KRAS promoter activity and KRAS expression. Inhibition of GLI using siRNA or the smoothened (Smo) inhibitor suppressed re-expression of KRAS in cells treated with a KRASG12C inhibitor. In addition, we demonstrate that KRASG12C inhibitors decreased Aurora kinase A (AURKA) levels in cancer cells, and inhibition of AURKA using siRNA or inhibitors led to increased expression levels of GLI-1 and KRAS even in the absence of KRAS inhibitor. Ectopic expression of AURKA attenuated the effect of KRASG12C inhibitors on the expression of GLI-1 and re-expression of KRAS. Together, these findings demonstrate the important role of AURKA, primary cilia, and Hedgehog signals in the re-expression of KRAS and therefore the induction of acquired resistance to KRASG12C inhibitors, and provide a rationale for targeting Hedgehog signalling to overcome acquired resistance to KRASG12C inhibitors.

Serum-Induced Proliferation of Human Cardiac Stem Cells Is Modulated via TGFβRI/II and SMAD2/3

The ageing phenotype is strongly driven by the exhaustion of adult stem cells (ASCs) and the accumulation of senescent cells. Cardiovascular diseases (CVDs) and heart failure (HF) are strongly linked to the ageing phenotype and are the leading cause of death. As the human heart is considered as an organ with low regenerative capacity, treatments targeting the rejuvenation of human cardiac stem cells (hCSCs) are of great interest. In this study, the beneficial effects of human blood serum on proliferation and senescence of hCSCs have been investigated at the molecular level. We show the induction of a proliferation-related gene expression response by human blood serum at the mRNA level. The concurrent differential expression of the TGFβ target and inhibitor genes indicates the participation of TGFβ signalling in this context. Surprisingly, the application of TGFβ1 as well as the inhibition of TGFβ type I and type II receptor (TGFβRI/II) signalling strongly increased the proliferation of hCSCs. Likewise, both human blood serum and TGFβ1 reduced the senescence in hCSCs. The protective effect of serum on senescence in hCSCs was enhanced by simultaneous TGFβRI/II inhibition. These results strongly indicate a dual role of TGFβ signalling in terms of the serum-mediated effects on hCSCs. Further analysis via RNA sequencing (RNA-Seq) revealed the participation of Ras-inactivating genes wherefore a prevention of hyperproliferation upon serum-treatment in hCSCs via TGFβ signalling and Ras-induced senescence is suggested. These insights may improve treatments of heart failure in the future.

Drugging the undruggable: Advances in targeting KRAS signaling in solid tumors

Cancer remains the leading cause of global mortality, prompting a paradigm shift in its treatment and outcomes with the advent of targeted therapies. Among the most prevalent mutations in RAS-driven cancers, Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations account for approximately 86% of cases worldwide, particularly in lung, pancreatic, and colon cancers, contributing to poor prognosis and reduced overall survival. Despite numerous efforts to understand the biology of KRAS mutants and their pivotal role in cancer development, the lack of well-defined drug-binding pockets has deemed KRAS an "undruggable" therapeutic target, presenting significant challenges for researchers and clinicians alike. Through significant biochemical and technological advances, the last decade has witnessed promising breakthroughs in targeted therapies for KRAS-mutated lung, colon, and pancreatic cancers, marking a critical turning point in the field. In this chapter, we provide an overview of the characteristics of KRAS mutations across various solid tumors, highlighting ongoing cutting-edge research on the immune microenvironment, the development of KRAS-driven mice models, and the recent progress in the exploration of specific KRAS mutant-targeted therapeutic approaches. By comprehensive understanding of the intricacies of KRAS signaling in solid tumors and the latest therapeutic developments, this chapter will shed light on the potential for novel therapeutic strategies to combat KRAS-driven tumors and improve patient outcomes.

Differential gene expression (DGE) analysis in persons with a history of giardiasis

Giardiasis, which is caused by Giardia duodenalis, has clinical symptoms such as steatorrhea and can be very dangerous in children. In addition, some documents reported that this parasite is present inside the tissue of patients with cancer. In this study, we analyzed the gene expression profiles of some main genes important to apoptosis and anti-apoptosis in humans.Expression profile arrays of Genomic Spatial Event (GSE) 113666, GSE113667, and GSE113679 obtained from Gene Expression Omnibus were used for meta-analysis using R commands. Cytoscape and STRING databases used the protein-protein Interaction network. Then, the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analysis was performed. Similar genes in Homo sapiens were identified using Basic Local Alignment Search Tool analysis. The validation was performed on eight people using real-time Polymerase chain reaction. In addition to the candidate genes, the gene expression of some other genes, including Serine/Threonine Kinase 1 (AKT1), Cyclin Dependent Kinase Inhibitor 2A (CDKN2A), Kirsten Rat Sarcoma (KRAS), and Phosphatidylinositol-4,5-Bisphosphate 3-Kinase Catalytic Subunit Alpha (PIK3CA) were also examined. Analysis of the expression of serum amyloid A1 (SAA1), Regenerating Islet-Derived 3 Gamma (REG3G), and REG3A genes did not show any difference between the two groups of healthy and diseased people. Examining the mean expression of the four genes AKT1, CDKN2A, KRAS, and PIK3CA showed that three genes of AKT1, CDKN2A, and KRAS had increased expression in people with a history of giardiasis compared to healthy people. We showed that the gene expression pattern differs in apoptosis and anti-apoptosis signaling in people with a history of giardiasis. Giardia duodenalis seems to induce post-non-infectious symptoms with stimulation of human gene expression.

The Abundance of KRAS and RAS Gene Mutations in Cancer

Mutant forms of the RAS genes KRAS, NRAS, and HRAS are important and common drivers of cancer. Recently, two independent teams that integrated cancer genomics with cancer epidemiology estimated that approximately 15-20% of all human cancers harbor a mutation in one of these three RAS genes. These groups also estimate KRAS mutations occur in 11-14% of all human cancers. Although these estimates are lower than many commonly encountered values, these estimates continue to rank KRAS and the ensemble of RAS oncogenes among the most common genetic drivers of cancer across all forms of malignancy.

Path Less Traveled: Targeting Rare Driver Oncogenes in Non-Small-Cell Lung Cancer

Over the past decade, tremendous efforts have been made in the development of targeted agents in non-small-cell lung cancer (NSCLC) with nonsquamous histology. Pivotal studies have used next-generation sequencing to select the patient population harboring oncogenic driver alterations that are targetable with targeted therapies. As treatment paradigm rapidly evolves for patients with rare oncogene-driven NSCLC, updated comprehensive overview of diagnostic approach and treatment options is paramount in clinical settings. In this review article, we discuss the epidemiology, molecular testing, and landmark clinical trials addressing the targeted agents for ROS1 rearrangement, METex14 skipping mutation, EGFR exon 20 insertion, KRAS G12C mutation, HER2 mutation, RET fusion, NTRK fusion, and BRAF mutations.

Next-generation therapies for pancreatic cancer

INTRODUCTION

Pancreas ductal adenocarcinoma (PDAC) is a frequently lethal malignancy that poses unique therapeutic challenges. The current mainstay of therapy for metastatic PDAC (mPDAC) is cytotoxic chemotherapy. NALIRIFOX (liposomal irinotecan, fluorouracil, leucovorin, oxaliplatin) is an emerging standard of care in the metastatic setting. An evolving understanding of PDAC pathogenesis is driving a shift toward targeted therapy. Olaparib, a poly-ADP-ribose polymerase (PARP) inhibitor, has regulatory approval for maintenance therapy in BRCA-mutated mPDAC along with other targeted agents receiving disease-agnostic approvals including for PDAC with rare fusions and mismatch repair deficiency. Ongoing research continues to identify and evaluate an expanding array of targeted therapies for PDAC.

AREAS COVERED

This review provides a brief overview of standard therapies for PDAC and an emphasis on current and emerging targeted therapies.

EXPERT OPINION

There is notable potential for targeted therapies for KRAS-mutated PDAC with opportunity for meaningful benefit for a sizable portion of patients with this disease. Further, emerging approaches are focused on novel immune, tumor microenvironment, and synthetic lethality strategies.