Targeting the untargetable KRAS in cancer therapy

Tunneling Nanotubes Mediate KRas Transport: Inducing Tumor Heterogeneity and Altering Cellular Membrane Mechanical Properties

Mutation in oncogene KRas plays a crucial role in the occurrence and progression of numerous malignant tumors. Malignancy involves changes in cell mechanics for extensive cellular deformation during metastatic dissemination. We hypothesize that oncogene KRas mutations are intrinsic to alterations in cellular mechanics that promote malignant tumor generation and progression. Here, we demonstrate the use of optical tweezers coupled with a confocal fluorescence imaging system and gene interference technique to reveal that the mutant KRas protein can be transported between homogeneous and heterogeneous tumor cells by tunneling nanotubes (TNTs), resulting in a significant reduction of membrane tension and acceleration of membrane phospholipid flow in the recipient cells. Simultaneously, the changes in membrane mechanical properties of the tumor cells also enhance the metastatic and invasive ability of the tumors, which further contribute to the deterioration of the tumors. This finding helps to clarify the association between oncogene mutations and changes in the mechanical properties of tumor cells, which provides a theoretical basis for the development of cancer treatment strategies. STATEMENT OF SIGNIFICANCE: Here, we present a laser confocal fluorescence system integrated with optical tweezers to observe the transfer of mutant KRasG12D protein from mutant cells to wild-type cells through TNTs. Malignancy involves changes in cell mechanics for extensive cellular deformation during metastatic dissemination. Our results demonstrate a significant decrease in membrane tension and an increase in membrane phospholipid flow in recipient cells. These alterations in mechanical properties augment the migration and invasive capabilities of tumor cells, contributing to tumor malignancy. Our findings propose that cellular mechanical properties could serve as new markers for tumor development, and targeting membrane tension may hold potential as a therapeutic strategy.

Cyclopeptide RA-V from Rubia yunnanensis restores activity of Adagrasib against colorectal cancer by reducing the expression of Nrf2

Adagrasib (MRTX849), an approved and promising KRAS G12C inhibitor, has shown the promising results for treating patients with advanced non-small cell lung cancer (NSCLC) or colorectal cancer (CRC) harboring KRAS-activating mutations. However, emergence of the acquired resistance limits its long-term efficacy and clinical application. Further understanding of the mechanism of the acquired resistance is crucial for developing more new effective therapeutic strategies. Herein, we firstly found a new connection between the acquired resistance to MRTX849 and nuclear factor erythroid 2-related factor 2 (Nrf2). The expression levels of Nrf2 and GLS1 proteins were substantially elevated in different CRC cell lines with the acquired resistance to MRTX849 in comparison with their corresponding parental cell lines. Next, we discovered that RA-V, one of natural cyclopeptides isolated from the roots of Rubia yunnanensis, could restore the response of resistant CRC cells to MRTX849. The results of molecular mechanisms showed that RA-V suppressed Nrf2 protein through the ubiquitin-proteasome-dependent degradation, leading to the induction of oxidative and ER stress, and DNA damage in CRC cell lines. Consequently, RA-V reverses the resistance to MRTX849 by inhibiting the Nrf2/GLS1 axis, which shows the potential for further developing into one of novel adjuvant therapies of MRTX849.

Peniapyrones A-I, Cytotoxic Tricyclic-Fused α-Pyrone Derivatives from an Endophytic Penicillium brefeldianum F4a

Five cyclopenta[d]pyrano[4,3-b]pyran-1,7(6H)-dione 6/6/5-fused tricyclic ring system containing metabolites peniapyrones A-E (1-5), and four previously undescribed cyclopenta[4,5]furo[3,2-c]pyran-1-one 6/5/5-fused tricyclic ring system containing compounds peniapyrones F-I (6-9), were isolated from the endophytic Penicillium brefeldianum F4a. Their structures, including absolute configurations, were determined through spectroscopic analysis and quantum chemical calculations. Peniapyrones D (4) and E (5) were a pair of diastereoisomers. Compounds 1, 3, and 5-9 showed cytotoxic activity against AsPC-1, CRL-2234, and MCF-7 cancer cell lines. Compounds 1, 3, 6, 8, and 9 inhibited the Kirsten rat sarcoma viral oncogene homologue (KRAS) mutant AsPC-1 cell line.

BET-directed PROTACs in triple negative breast cancer cell lines MDA-MB-231 and MDA-MB-436

PURPOSE

This study aims to find whether the proliferation and migration of triple negative breast cancer (TNBC) cell lines can be reduced by treatment with bromodomain and extra-terminal domain (BET) inhibitor JQ1 and BET protein targeting chimeras (PROTACs) ARV-771 and MZ1.

METHODS

Cytotoxicity tests, scratch migration assays and western blot proteome profiler arrays for protein expression of cancer-related proteins were used to evaluate the impact of a BET-inhibitor and two BET-directed PROTACs on cell viability, migration and on protein expression.

RESULTS

JQ1 and the PROTACs MZ1 and ARV-771 significantly inhibited the growth and migration of the KRAS G13D-mutated MDA-MB-231 cells. In this cell line, the PROTACs suppressed the residual expression of ERBB2/HER2, 3 and 4 that are essential for the proliferation of breast cancer cells and this cell line proved sensitive to HER2 inhibitors. In contrast, the effects of the PROTACs on the protein expression of MDA-MB-436 cells mostly affected cytokines and their cognate receptors.

CONCLUSION

The degradation of BET-protein by PROTACs demonstrated significant anti-proliferative effects. The KRAS-mutated MDA-MB-231 cells belong to the low-HER2 expressing tumors that have a poorer prognosis compared to HER2-null patients. Since first oral PROTACs against tumor hormone receptors are in clinical trials, this mode of tumor therapy is expected to become an important therapeutic strategy in the future treatment of TNBC.

Gemcitabine-loaded chitosan nanoparticles enhanced apoptotic and ferroptotic response of gemcitabine treatment alone in the pancreatic cancer cells in vitro

Gemcitabine (GEM) is a first-line treatment for pancreatic ductal adenocarcinoma (PDAC) patients, causing side effects and poor overall survival. Eighty percent of patients often develop resistance rapidly to GEM. Developing therapeutic approaches and increasing sensitivity to gemcitabine in PDAC has become one of the challenges in cancer research. We synthesized GEM-loaded NPs prepared with a method that combines ultrasonication and ionotropic gelation to overcome GEM-related limitations in PDAC. CFPAC-1 cells were treated with increased concentrations of GEM, empty chitosan, and GEM-loaded NPs (0.66, 1.32, 2.64, 5.32 µg/ml) for up to 48 h. Empty chitosan NPs did not show toxicity on L929 cells. Antioxidant enzyme activities, including glucose 6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6-PGD), glutathione reductase (GR), glutathione s-transferase (GST), and glutathione peroxidase (GPx), significantly reduced in GEM-loaded NPs compared to the GEM associated with increased oxidative stress, PPP, and glycolysis. Bcl-xL, NOXA/mcl-1, and Ca2+ levels significantly increased in GEM-loaded NP-administered cells compared to the GEM and control groups. In contrast, JNK, p38, STAT3, Akt, and CREB levels significantly decreased in the GEM-loaded NP group, addressing enhanced apoptotic response compared to the GEM alone. Increased ferroptosis activity in GEM-loaded NP-administered groups has been validated via decreased antioxidant enzyme activities, increased cytosolic Fe, Zn, Mg, and Mn levels, and reduced GPx activity compared to the GEM and control groups. For the first time in the literature, we showed biocompatible GEM-loaded NPs enhanced apoptotic and ferroptotic response in CFPAC-1 cells via downregulation of antioxidant, glycolysis, and PPP metabolism compared to the GEM alone.

Atherosclerosis Is a Smooth Muscle Cell-Driven Tumor-Like Disease

BACKGROUND

Atherosclerosis, a leading cause of cardiovascular disease, involves the pathological activation of various cell types, including immunocytes (eg, macrophages and T cells), smooth muscle cells (SMCs), and endothelial cells. Accumulating evidence suggests that transition of SMCs to other cell types, known as phenotypic switching, plays a central role in atherosclerosis development and complications. However, the characteristics of SMC-derived cells and the underlying mechanisms of SMC transition in disease pathogenesis remain poorly understood. Our objective is to characterize tumor cell-like behaviors of SMC-derived cells in atherosclerosis, with the ultimate goal of developing interventions targeting SMC transition for the prevention and treatment of atherosclerosis.

METHODS

We used SMC lineage tracing mice and human tissues and applied a range of methods, including molecular, cellular, histological, computational, human genetics, and pharmacological approaches, to investigate the features of SMC-derived cells in atherosclerosis.

RESULTS

SMC-derived cells in mouse and human atherosclerosis exhibit multiple tumor cell-like characteristics, including genomic instability, evasion of senescence, hyperproliferation, resistance to cell death, invasiveness, and activation of comprehensive cancer-associated gene regulatory networks. Specific expression of the oncogenic mutant KrasG12D in SMCs accelerates phenotypic switching and exacerbates atherosclerosis. Furthermore, we provide proof of concept that niraparib, an anticancer drug targeting DNA damage repair, attenuates atherosclerosis progression and induces regression of lesions in advanced disease in mouse models.

CONCLUSIONS

Our findings demonstrate that atherosclerosis is an SMC-driven tumor-like disease, advancing our understanding of its pathogenesis and opening prospects for innovative precision molecular strategies aimed at preventing and treating atherosclerotic cardiovascular disease.

Targeting the molecular chaperone CCT2 inhibits GBM progression by influencing KRAS stability

Proper protein folding relies on the assistance of molecular chaperones post-translation. Dysfunctions in chaperones can cause diseases associated with protein misfolding, including cancer. While previous studies have identified CCT2 as a chaperone subunit and an autophagy receptor, its specific involvement in glioblastoma remains unknown. Here, we identified CCT2 promote glioblastoma progression. Using approaches of coimmunoprecipitation, mass spectrometry and surface plasmon resonance, we found CCT2 directly bound to KRAS leading to increased stability and upregulated downstream signaling of KRAS. Interestingly, we found that dihydroartemisinin, a derivative of artemisinin, exhibited therapeutic effects in a glioblastoma animal model. We further demonstrated direct binding between dihydroartemisinin and CCT2. Treatment with dihydroartemisinin resulted in decreased KRAS expression and downstream signaling. Highlighting the significance of CCT2, CCT2 overexpression rescued the inhibitory effect of dihydroartemisinin on glioblastoma. In conclusion, the study demonstrates that CCT2 promotes glioblastoma progression by directly binding to and enhancing the stability of the KRAS protein. Additionally, dihydroartemisinin inhibits glioblastoma by targeting the CCT2 and the following KRAS signaling. Our findings overcome the challenge posed by the undruggable nature of KRAS and offer potential therapeutic strategies for glioblastoma treatment.

Hippo pathway in non-small cell lung cancer: mechanisms, potential targets, and biomarkers

Lung cancer is the primary contributor to cancer-related deaths globally, and non-small cell lung cancer (NSCLC) constitutes around 85% of all lung cancer cases. Recently, the emergence of targeted therapy and immunotherapy revolutionized the treatment of NSCLC and greatly improved patients' survival. However, drug resistance is inevitable, and extensive research has demonstrated that the Hippo pathway plays a crucial role in the development of drug resistance in NSCLC. The Hippo pathway is a highly conserved signaling pathway that is essential for various biological processes, including organ development, maintenance of epithelial balance, tissue regeneration, wound healing, and immune regulation. This pathway exerts its effects through two key transcription factors, namely Yes-associated protein (YAP) and transcriptional co-activator PDZ-binding motif (TAZ). They regulate gene expression by interacting with the transcriptional-enhanced associate domain (TEAD) family. In recent years, this pathway has been extensively studied in NSCLC. The review summarizes a comprehensive overview of the involvement of this pathway in NSCLC, and discusses the mechanisms of drug resistance, potential targets, and biomarkers associated with this pathway in NSCLC.

Oncogenic mutations of KRAS modulate its turnover by the CUL3/LZTR1 E3 ligase complex

KRAS is a proto-oncogene encoding a small GTPase. Mutations contribute to ∼30% of human solid tumours, including lung adenocarcinoma, pancreatic, and colorectal carcinomas. Most KRAS activating mutations interfere with GTP hydrolysis, essential for its role as a molecular switch, leading to alterations in their molecular environment and oncogenic signalling. However, the precise signalling cascades these mutations affect are poorly understood. Here, APEX2 proximity labelling was used to profile the molecular environment of WT, G12D, G13D, and Q61H-activating KRAS mutants under starvation and stimulation conditions. Through quantitative proteomics, we demonstrate the presence of known KRAS interactors, including ARAF and LZTR1, which are differentially captured by WT and KRAS mutants. Notably, the KRAS mutations G12D, G13D, and Q61H abrogate their association with LZTR1, thereby affecting turnover. Elucidating the implications of LZTR1-mediated regulation of KRAS protein levels in cancer may offer insights into therapeutic strategies targeting KRAS-driven malignancies.

Brusatol attenuated proliferation and invasion induced by KRAS in differentiated thyroid cancer through inhibiting Nrf2

BACKGROUND

Poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC) can be developed from differentiated thyroid cancer, and this dedifferentiated transformation leads to poor prognosis and high mortality. The role of Nrf2 in the dedifferentiation of differentiated thyroid cancer (DTC) induced by KRAS remains unclear.

METHODS AND MATERIALS

In this study, two DTC cell lines, BCPAP and WRO, were used to evaluate the function of Nrf2 in the dedifferentiation caused by wild-type KRAS (KRAS-WT) and G12V point mutation KRAS (KRAS-G12V).

RESULTS

The overexpression of KRAS-WT and KRAS-G12V increased the proliferative and invasive ability of BCPAP and WRO cells. Aggressive morphology was observed in KRAS-WT and KRAS-G12V overexpressed WRO cells. These results suggested that overexpression of KRAS-WT or KRAS-G12V may induce dedifferentiation in DTC cells. The expression of Nrf2 was increased by KRAS-WT and KRAS-G12V in DTC cells. In addition, compared with normal thyroid tissues, the expression of Nrf2 protein was considerably higher in thyroid cancer tissues on immunohistochemistry (IHC) staining, and the increased expression of Nrf2 indicated a poor prognosis of thyroid cancer. These results indicated that Nrf2 is the KRAS downstream molecule in thyroid cancer. Functional studies showed that the Nrf2 inhibitor Brusatol counteracted the proliferative and invasive abilities induced by KRAS-WT and KRAS-G12V in BCPAP and WRO cells. In addition, the xenograft assay further confirmed that Brusatol inhibits tumor growth induced by KRAS-WT and KRAS-G12V.

CONCLUSION

Collectively, this study suggests that Nrf2 could be a promising therapeutic target in KRAS-mediated dedifferentiation of thyroid cancer.

Targeting KRAS in pancreatic cancer

Pancreatic cancer has a dismal prognosis due to late detection and lack of efficient therapies. The Kirsten rat sarcoma virus (KRAS) oncogene is mutated in up to 90% of all pancreatic ductal adenocarcinomas (PDACs) and constitutes an attractive target for therapy. However, the most common KRAS mutations in PDAC are G12D (44%), G12V (34%) and G12R (20%) that are not amenable to treatment by KRAS G12C-directed cysteine-reactive KRAS inhibitors such as Sotorasib and Adagrasib that exhibit clinical efficacy in lung cancer. KRAS G12C mutant pancreatic cancer has been treated with Sotorasib but this mutation is detected only in 2%-3% of PDAC. Recently, the KRAS G12D-directed MRTX1133 inhibitor has entered clinical trials and more of such inhibitors are in development. The other KRAS mutations may be targeted indirectly via inhibition of the cognate guanosine exchange factor (GEF) Son of Sevenless 1 that drives KRAS. These agents seem to provide the means to target the most frequent KRAS mutations in PDAC and to improve patient outcomes.

Current advances and development strategies of targeting son of sevenless 1 (SOS1) in drug discovery

The Son of Sevenless 1 (SOS1) guanine nucleotide exchange factor, prevalent across eukaryotic species, plays a pivotal role in facilitating the attachment of RAS protein to GTP, thereby regulating the activation of intracellular RAS proteins. This regulation is part of a feedback mechanism involving SOS1, which allows both activators and inhibitors of SOS1 to exert control over downstream signaling pathways, demonstrating potential anti-tumor effects. Predominantly, small molecule modulators that target SOS1 focus on a hydrophobic pocket within the CDC25 protein domain. The effectiveness of these modulators largely depends on their ability to interact with specific amino acids, notably Phe890 and Tyr884. This interaction is crucial for influencing the protein-protein interaction (PPI) between RAS and the catalytic domain of SOS1. Currently, most small molecule modulators targeting SOS1 are in the preclinical research phase, with a few advancing to clinical trials. This progression raises safety concerns, making the assurance of drug safety a primary consideration alongside the enhancement of efficacy in the development of SOS1 modulators. This review encapsulates recent advancements in the chemical categorization of SOS1 inhibitors and activators. It delves into the evolution of small molecule modulation targeting SOS1 and offers perspectives on the design of future generations of selective SOS1 small molecule modulators.

Assessment of RAS-RAF-MAPK Pathway Mutation Status in Healthy Skin, Benign Nevi, and Cutaneous Melanomas: Pilot Study Using Droplet Digital PCR

In the present study, we employed the ddPCR and IHC techniques to assess the prevalence and roles of RAS and RAF mutations in a small batch of melanoma (n = 22), benign moles (n = 15), and normal skin samples (n = 15). Mutational screening revealed the coexistence of BRAF and NRAS mutations in melanomas and nevi and the occurrence of NRAS G12/G13 variants in healthy skin. All investigated nevi had driver mutations in the BRAF or NRAS genes and elevated p16 protein expression, indicating cell cycle arrest despite an increased mutational burden. BRAF V600 mutations were identified in 54% of melanomas, and NRAS G12/G13 mutations in 50%. The BRAF mutations were associated with the Breslow index (BI) (p = 0.029) and TIL infiltration (p = 0.027), whereas the NRAS mutations correlated with the BI (p = 0.01) and the mitotic index (p = 0.04). Here, we demonstrate that the "young" ddPCR technology is as effective as a CE-IVD marked real-time PCR method for detecting BRAF V600 hotspot mutations in tumor biopsies and recommend it for extended use in clinical settings. Moreover, ddPCR was able to detect low-frequency hotspot mutations, such as NRAS G12/G13, in our tissue specimens, which makes it a promising tool for investigating the mutational landscape of sun-damaged skin, benign nevi, and melanomas in more extensive clinical studies.

The Clinicopathological Correlation of KRAS Mutation and PTEN Expression Status in Primary and Metastatic Colorectal Carcinoma

BACKGROUND

Colorectal cancer (CRC) research has identified a consistent loss of PTEN expression in both primary tumors and metastasis, highlighting its potential role in this disease. However, the impact of PTEN on downstream proteins of KRAS mutation, namely p-AKT, p-ERK, and p65 (NFkB), remains unknown. This study aims to explore the inhibitory effect of PTEN on KRAS downstream proteins and its correlation with pathological features in CRC patients.

METHODS

From January 1, 2015, to December 31, 2021, 86 CRC cases were collected from governmental and private laboratories in the Duhok province. Formalin-fixed, paraffin-embedded tissue blocks were obtained, and the study involved histopathological analysis, immunohistochemistry of PTEN, AKT, ERK, and P65 markers, and molecular analysis of the KRAS gene.

RESULTS

Among the 86 cases, there were 46 males (53.5%) and 40 females (46.5%), with an equal distribution between right colon and left colon/rectum. Tumors larger than 5cm were observed in 47 cases, predominantly displaying a polypoid or ulcerated growth pattern. Most cases were moderately differentiated adenocarcinomas, with stages II and III being the most prevalent 31 cases (36%) and 34 cases (39.5%) respectively. Significant associations were found between PTEN, ERK expressions, and tumor location in the right colon (P=0.031 and P=0.009 respectively). Tumor size correlated with P65 expression (P=0.042). KRAS mutation showed a positive relationship with the type of tumor growth (P=0.035). Tumor grade increased with KRAS mutations (P=0.043). PTEN expression correlated significantly with ERK and AKT markers (P=0.018 and 0.035 respectively). P65 exhibited an association with KRAS mutation (P=0.034).

CONCLUSION

The study revealed PTEN expression in association with the inhibition of AKT and ERK, and the absence of KRAS gene mutation. Conversely, PTEN is not expressed with the positively reactive P65 and the presence of KRAS mutation. This study contributes valuable insights into the complex interplay between PTEN expression, KRAS mutation, and downstream signaling pathways in CRC. It suggests potential avenues for further research and therapeutic strategies in the context of CRC treatment.

Deciphering the role of KRAS gene in oncogenesis: Focus on signaling pathways, genetic alterations in 3'UTR, KRAS specific miRNAs and therapeutic interventions

Cancer is a significant cause of death after cardiovascular disease. The genomic, epigenetic and environmental factors have been found to be the risk factor for the disease. The most important genes that develop cancer are oncogenes and tumor suppressor genes. Among oncogenes, KRAS has emerged as a significant player in the development of many cancers. Dysregulation of the RAS signaling pathway either on account of mutation in significant genes involved in the pathway or aberrant expression of different miRNAs targeting these genes including KRAS. The focus is also on the alterations in 3'UTR of the KRAS gene sequence as well as the changes in the miRNA encoding genes especially the one targeting the KRAS gene. Efforts are also being put in to target the dysregulated KRAS gene as a therapeutic approach to treat different cancers. However, there are some challenges like resistance to KRAS inhibitors that need to be addressed.

Ganoderma microsporum immunomodulatory protein combined with KRASG12C inhibitor impedes intracellular AKT/ERK network to suppress lung cancer cells with KRAS mutation

KRAS mutations are tightly associated with lung cancer progression. Despite the unprecedented clinical success of KRASG12C inhibitors, recurrent mechanisms of resistance and other KRAS mutations require further therapeutic approaches. GMI, a protein from the medicinal mushroom Ganoderma microsporum, possesses antitumor activity; whereas, the biological function of GMI on regulating KRAS mutant lung cancer cells remains unknown. Herein, RNA-sequencing and bioinformatics showed that GMI may regulate KRAS-modulated MAPK and PI3K-AKT pathways in A549 (KRASG12S) cells. Further experiments demonstrated that GMI inhibited KRAS activation and suppressed ERK1/2 and AKT signaling in A549 cells. Intriguingly, GMI inhibited AKT signaling but increased phosphorylation of ERK in H358 (KRASG12C) cells. GMI significantly suppressed tumor growth in LLC1 cells-allograft and H358 cells-xenograft mice. GMI showed a synergistic effect with KRASG12C inhibitors in inhibiting cell growth, KRAS activation and KRAS-mediated downstream signaling, leading to apoptosis in H358 cells. Combination of GMI and KRASG12C inhibitor, AMG 510, resulted in more durable inhibition of tumor growth and KRAS activity in H358 cells-xenograft mice. This study highlights the potential of GMI, a dietary fungal protein, as a viable therapeutic avenue for KRAS-mutant lung cancer in combination with KRASG12C inhibitors.

Direct K-Ras Inhibitors to Treat Cancers: Progress, New Insights, and Approaches to Treat Resistance

Here we discuss approaches to K-Ras inhibition and drug resistance scenarios. A breakthrough offered a covalent drug against K-RasG12C. Subsequent innovations harnessed same-allele drug combinations, as well as cotargeting K-RasG12C with a companion drug to upstream regulators or downstream kinases. However, primary, adaptive, and acquired resistance inevitably emerge. The preexisting mutation load can explain how even exceedingly rare mutations with unobservable effects can promote drug resistance, seeding growth of insensitive cell clones, and proliferation. Statistics confirm the expectation that most resistance-related mutations are in cis, pointing to the high probability of cooperative, same-allele effects. In addition to targeted Ras inhibitors and drug combinations, bifunctional molecules and innovative tri-complex inhibitors to target Ras mutants are also under development. Since the identities and potential contributions of preexisting and evolving mutations are unknown, selecting a pharmacologic combination is taxing. Collectively, our broad review outlines considerations and provides new insights into pharmacology and resistance.

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.

Identification of novel 3-aryl-1-aminoisoquinolines-based KRASG12C inhibitors: Rational drug design and expedient construction by CH functionalization/annulation

Developing a synthetic methodology to expediently construct a specific drug scaffold with the desired biological activity remains challenging. Herein, we describe a work on rational application of a synthetic methodology in the synthesis of KRASG12C inhibitors. Novel KRASG12C inhibitors were initially designed with 1-amino-3-aryl isoquinoline scaffold using structure-based drug design strategy. A ruthenium-catalyzed direct monoCH functionalization/annulation cascade reaction of amidines and sulfoxonium ylides was then developed with high versatility of substrates and good tolerance for polar functional groups. By using this reaction, the target compounds 1-amino-3-aryl isoquinolines were facilely prepared. Further in vitro tests led to identification of two novel lead compounds with KRASG12C inhibitory activity.

PWSC: a novel clustering method based on polynomial weight-adjusted sparse clustering for sparse biomedical data and its application in cancer subtyping

BACKGROUND

Clustering analysis is widely used to interpret biomedical data and uncover new knowledge and patterns. However, conventional clustering methods are not effective when dealing with sparse biomedical data. To overcome this limitation, we propose a hierarchical clustering method called polynomial weight-adjusted sparse clustering (PWSC).

RESULTS

The PWSC algorithm adjusts feature weights using a polynomial function, redefines the distances between samples, and performs hierarchical clustering analysis based on these adjusted distances. Additionally, we incorporate a consensus clustering approach to determine the optimal number of classifications. This consensus approach utilizes relative change in the cumulative distribution function to identify the best number of clusters, resulting in more stable clustering results. Leveraging the PWSC algorithm, we successfully classified a cohort of gastric cancer patients, enabling categorization of patients carrying different types of altered genes. Further evaluation using Entropy showed a significant improvement (p = 2.905e-05), while using the Calinski-Harabasz index demonstrates a remarkable 100% improvement in the quality of the best classification compared to conventional algorithms. Similarly, significantly increased entropy (p = 0.0336) and comparable CHI, were observed when classifying another colorectal cancer cohort with microbial abundance. The above attempts in cancer subtyping demonstrate that PWSC is highly applicable to different types of biomedical data. To facilitate its application, we have developed a user-friendly tool that implements the PWSC algorithm, which canbe accessed at http://pwsc.aiyimed.com/ .

CONCLUSIONS

PWSC addresses the limitations of conventional approaches when clustering sparse biomedical data. By adjusting feature weights and employing consensus clustering, we achieve improved clustering results compared to conventional methods. The PWSC algorithm provides a valuable tool for researchers in the field, enabling more accurate and stable clustering analysis. Its application can enhance our understanding of complex biological systems and contribute to advancements in various biomedical disciplines.

Studying early structural changes in SOS1 mediated KRAS activation mechanism

KRAS activation is known to be modulated by a guanine nucleotide exchange factor (GEF), namely, Son of Sevenless1 (SOS1). SOS1 facilitates the exchange of GDP to GTP thereby leading to activation of KRAS. The binding of GDP/GTP to KRAS at the REM/allosteric site of SOS1 regulates the activation of KRAS at CDC25/catalytic site by facilitating its exchange. Different aspects of the allosteric activation of KRAS through SOS1 are still being explored. To understand the SOS1 mediated activation of KRAS, molecular dynamics simulations for a total of nine SOS1 complexes (KRAS-SOS1-KRAS) were performed. These nine systems comprised different combinations of KRAS-bound nucleotides (GTP/GDP) at REM and CDC25 sites of SOS1. Various conformational and thermodynamic parameters were analyzed for these simulation systems. MMPBSA free energy analysis revealed that binding at CDC25 site of SOS1 was significantly low for GDP-bound KRAS as compared to that of GTP-bound KRAS. It was observed that presence of either GDP/GTP bound KRAS at the REM site of SOS1 affected the activation related changes in the KRAS present at CDC25 site. The conformational changes at the catalytic site of SOS1 resulting from GDP/GTP-bound KRAS at the allosteric changes may hint at KRAS activation through different pathways (slow/fast/rare). The allosteric effect on activation of KRAS at CDC25 site may be due to conformations adopted by switch-I, switch-II, beta2 regions of KRAS at REM site. The effect of structural rearrangements occurring at allosteric KRAS may have led to increased interactions between SOS1 and KRAS at both the sites. The SOS1 residues involved in these important interactions with KRAS at the REM site were R694, S732 and K735. Whereas the ones interacting with KRAS at CDC25 site were S807, W809 and K814. This may suggest the crucial role of these residues in guiding the allosteric activation of KRAS at CDC25 site. The conformational shifts observed in the switch-I, switch-II and alpha3 regions of KRAS at CDC25 site may be attributed to be a part of allosteric activation. The binding affinities, interacting residues and conformational dynamics may provide an insight into development of inhibitors targeting the SOS1 mediated KRAS activation.

In silico design of a lipid-like compound targeting KRAS4B-G12D through non-covalent bonds

One of the most common drivers in human cancer is the peripheral membrane protein KRAS4B, able to promote oncogenic signalling. To signal, oncogenic KRAS4B not only requires a sufficient nucleotide exchange, but also needs to recruit effectors by exposing its effector-binding sites while anchoring to the phospholipid bilayer where KRAS4B-mediated signalling events occur. The enzyme phosphodiesterase-δ plays an important role in sequestering KRAS4B from the cytoplasm and targeting it to cellular membranes of different cell species. In this work, we present an in silico design of a lipid-like compound that has the remarkable feature of being able to target both an oncogenic KRAS4B-G12D mutant and the phosphodiesterase-δ enzyme. This double action is accomplished by adding a lipid tail (analogous to the farnesyl group of the KRAS4B protein) to an previously known active compound (2H-1,2,4-benzothiadiazine, 3,4-dihydro-,1,1-dioxide). The proposed lipid-like molecule was found to lock KRAS4B-G12D in its GDP-bound state by adjusting the effector-binding domain to be blocked by the interface of the lipid bilayer. Meanwhile, it can tune GTP-bound KRAS4B-G12D to shift from the active orientation state to the inactive state. The proposed compound is also observed to stably accommodate itself in the prenyl-binding pocket of phosphodiesterase-δ, which impairs KRAS4B enrichment at the lipid bilayer, potentially reducing the proliferation of KRAS4B inside the cytoplasm and its anchoring at the bilayer. In conclusion, we report a potential inhibitor of KRAS4B-G12D with a lipid tail attached to a specific warhead, a compound which has not yet been considered for drugs targeting RAS mutants. Our work provides new ways to target KRAS4B-G12D and can also foster drug discovery efforts for the targeting of oncogenes of the RAS family and beyond.

Identifying genes associated with resistance to KRAS G12C inhibitors via machine learning methods

BACKGROUND

Targeted therapy has revolutionized cancer treatment, greatly improving patient outcomes and quality of life. Lung cancer, specifically non-small cell lung cancer, is frequently driven by the G12C mutation at the KRAS locus. The development of KRAS inhibitors has been a breakthrough in the field of cancer research, given the crucial role of KRAS mutations in driving tumor growth and progression. However, over half of patients with cancer bypass inhibition show limited response to treatment. The mechanisms underlying tumor cell resistance to this treatment remain poorly understood.

METHODS

To address above gap in knowledge, we conducted a study aimed to elucidate the differences between tumor cells that respond positively to KRAS (G12C) inhibitor therapy and those that do not. Specifically, we analyzed single-cell gene expression profiles from KRAS G12C-mutant tumor cell models (H358, H2122, and SW1573) treated with KRAS G12C (ARS-1620) inhibitor, which contained 4297 cells that continued to proliferate under treatment and 3315 cells that became quiescent. Each cell was represented by the expression levels on 8687 genes. We then designed an innovative machine learning based framework, incorporating seven feature ranking algorithms and four classification algorithms to identify essential genes and establish quantitative rules.

RESULTS

Our analysis identified some top-ranked genes, including H2AFZ, CKS1B, TUBA1B, RRM2, and BIRC5, that are known to be associated with the progression of multiple cancers.

CONCLUSION

Above genes were relevant to tumor cell resistance to targeted therapy. This study provides important insights into the molecular mechanisms underlying tumor cell resistance to KRAS inhibitor treatment.

Spatholobus suberectus inhibits lipogenesis and tumorigenesis in triple-negative breast cancer via activation of AMPK-ACC and K-Ras-ERK signaling pathway

Background and aim

Triple-negative breast cancer (TNBC) is a highly invasive type of breast cancer with a poor prognosis. Currently, there are no effective management strategies for TNBC. Earlier, our lab reported the percolation of Spatholobus suberectus for the treatment of breast cancer. Lipid metabolic reprogramming is a hallmark of cancer. However, the anti-TNBC efficiency of S. suberectus extract and its causal mechanism for preventing lipogenesis have not been fully recognized. Hence, the present study aimed to investigate the inhibitory role of S. suberectus extract on lipogenesis and tumorigenesis in TNBC in vitro and in vivo by activating AMPK-ACC and K-Ras-ERK signaling pathways using lipidomic and metabolomic techniques.

Experimental procedure

Dried stems of S. suberectus extract inhibited lipogenesis and tumorigenesis and promoted fatty acid oxidation as demonstrated by the identification of the metabolites and fatty acid markers using proteomic and metabolomic analysis, qPCR, and Western blot.

Results and conclusion

The results indicated that S. suberectus extract promotes fatty acid oxidation and suppresses lipogenic metabolites and biomarkers, thereby preventing tumorigenesis via the AMPK-ACC and K-Ras-ERK signaling pathways. On the basis of this preclinical evidence, we suggest that this study represents a milestone and complements Chinese medicine. Further studies remain underway in our laboratory to elucidate the active principles of S. suberectus extract. This study suggests that S. suberectus extract could be a promising therapy for TNBC.

New drug approvals for 2022: Synthesis and clinical applications

The U.S. Food and Drug Administration has approved a total of 37 new drugs in 2022, which are composed of 20 chemical entities and 17 biologics. In particular, 20 chemical entities, including 17 small molecule drugs, 1 radiotherapy, and 2 diagnostic agents, provide privileged scaffolds, breakthrough clinical benefits, and a new mechanism of action for the discovery of more potent clinical candidates. The structure-based drug development with clear targets and fragment-based drug development with privileged scaffolds have always been the important modules in the field of drug discovery, which could easily bypass the patent protection and bring about improved biological activity. Therefore, we summarized the relevant valuable information about clinical application, mechanism of action, and chemical synthesis of 17 newly approved small molecule drugs in 2022. We hope this timely and comprehensive review could bring about creative and elegant inspiration on the synthetic methodologies and mechanism of action for the discovery of new drugs with novel chemical scaffolds and extended clinical indications.

KRASG12C inhibition using MRTX1257: a novel radio-sensitizing partner

BACKGROUND

KRAS activating mutations are considered the most frequent oncogenic drivers and are correlated with radio-resistance in multiple cancers including non-small cell lung cancer (NSCLC) and colorectal cancer. Although KRAS was considered undruggable until recently, several KRAS inhibitors have recently reached clinical development. Among them, MRTX849 (Mirati Therapeutics) showed encouraging clinical outcomes for the treatment of selected patients with KRASG12C mutated NSCLC and colorectal cancers. In this work, we explore the ability of MRTX1257, a KRASG12C inhibitor analogous to MRTX849, to radio-sensitize KRASG12C+/+ mutated cell lines and tumors.

METHODS

Both in vitro and in vivo models of radiotherapy (RT) in association with MRTX1257 were used, with different RAS mutational profiles. We assessed in vitro the radio-sensitizing effect of MRTX1257 in CT26 KRASG12C+/+, CT26 WT, LL2 WT and LL2 NRAS KO (LL2 NRAS-/-) cell lines. In vivo, we used syngeneic models of subcutaneous CT26 KRASG12C+/+ tumors in BALB/c mice and T cell deficient athymic nu/nu mice to assess both the radio-sensitizing effect of MRTX1257 and its immunological features.

RESULTS

MRTX1257 was able to radio-sensitize CT26 KRASG12C+/+ cells in vitro in a time and dose dependent manner. Moreover, RT in association with MRTX1257 in BALB/c mice bearing CT26 KRASG12C+/+ subcutaneous tumors resulted in an observable cure rate of 20%. However, no durable response was observed with similar treatment in athymic nude mice. The analysis of the immune microenvironment of CT26 KRASG12C+/+ tumors following RT and MRTX1257 showed an increase in the proportion of various cell subtypes including conventional CD4 + T cells, dendritic cells type 2 (cDC2) and inflammatory monocytes. Furthermore, the expression of PD-L1 was dramatically down-regulated within both tumor and myeloid cells, thus illustrating the polarization of the tumor microenvironment towards a pro-inflammatory and anti-tumor phenotype following the combined treatment.

CONCLUSION

This work is the first to demonstrate in vitro as in vivo the radio-sensitizing effect of MRTX1257, a potent KRASG12C inhibitor compatible with oral administration, in CT26 KRASG12C mutated cell lines and tumors. This is a first step towards the use of new combinatorial strategies using KRAS inhibitors and RT in KRASG12C mutated tumors, which are the most represented in NSCLC with 14% of patients harboring this mutational profile.

Aging, oxidative stress and degenerative diseases: mechanisms, complications and emerging therapeutic strategies

Aging accompanied by several age-related complications, is a multifaceted inevitable biological progression involving various genetic, environmental, and lifestyle factors. The major factor in this process is oxidative stress, caused by an abundance of reactive oxygen species (ROS) generated in the mitochondria and endoplasmic reticulum (ER). ROS and RNS pose a threat by disrupting signaling mechanisms and causing oxidative damage to cellular components. This oxidative stress affects both the ER and mitochondria, causing proteopathies (abnormal protein aggregation), initiation of unfolded protein response, mitochondrial dysfunction, abnormal cellular senescence, ultimately leading to inflammaging (chronic inflammation associated with aging) and, in rare cases, metastasis. RONS during oxidative stress dysregulate multiple metabolic pathways like NF-κB, MAPK, Nrf-2/Keap-1/ARE and PI3K/Akt which may lead to inappropriate cell death through apoptosis and necrosis. Inflammaging contributes to the development of inflammatory and degenerative diseases such as neurodegenerative diseases, diabetes, cardiovascular disease, chronic kidney disease, and retinopathy. The body's antioxidant systems, sirtuins, autophagy, apoptosis, and biogenesis play a role in maintaining homeostasis, but they have limitations and cannot achieve an ideal state of balance. Certain interventions, such as calorie restriction, intermittent fasting, dietary habits, and regular exercise, have shown beneficial effects in counteracting the aging process. In addition, interventions like senotherapy (targeting senescent cells) and sirtuin-activating compounds (STACs) enhance autophagy and apoptosis for efficient removal of damaged oxidative products and organelles. Further, STACs enhance biogenesis for the regeneration of required organelles to maintain homeostasis. This review article explores the various aspects of oxidative damage, the associated complications, and potential strategies to mitigate these effects.

MicroRNA-143 as a potential tumor suppressor in cancer: An insight into molecular targets and signaling pathways

MicroRNAs (MiRNAs), which are highly conserved and small noncoding RNAs, negatively regulate gene expression and influence signaling pathways involved in essential biological activities, including cell proliferation, differentiation, apoptosis, and cell invasion. MiRNAs have received much attention in the past decade due to their significant roles in cancer development. In particular, microRNA-143 (miR-143) is recognized as a tumor suppressor and is downregulated in most cancers. However, it seems that miR-143 is upregulated in rare cases, such as prostate cancer stem cells, and acts as an oncogene. The present review will outline the current studies illustrating the impact of miR-143 expression levels on cancer progression and discuss its target genes and their relevant signaling pathways to discover a potential therapeutic way for cancer.

Intracranial Efficacy of Adagrasib in Patients From the KRYSTAL-1 Trial With KRASG12C-Mutated Non-Small-Cell Lung Cancer Who Have Untreated CNS Metastases

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Patients with Kirsten rat sarcoma viral oncogene homolog (KRAS)-mutated non-small-cell lung cancer (NSCLC) and untreated CNS metastases have a worse prognosis than similar patients without KRAS mutations. Adagrasib has previously demonstrated CNS penetration preclinically and cerebral spinal fluid penetration clinically. We evaluated adagrasib in patients with KRASG12C-mutated NSCLC and untreated CNS metastases from the KRYSTAL-1 trial (ClinicalTrials.gov identifier: NCT03785249; phase Ib cohort), in which adagrasib 600 mg was administered orally, twice daily. Study outcomes included the safety and clinical activity (intracranial [IC] and systemic) by blinded independent central review. Twenty-five patients with KRASG12C-mutated NSCLC and untreated CNS metastases were enrolled and evaluated (median follow-up, 13.7 months); 19 patients were radiographically evaluable for IC activity. Safety was consistent with previous reports of adagrasib, with grade 3 treatment-related adverse events (TRAEs) in 10 patients (40%) and one grade 4 (4%) and no grade 5 TRAEs. The most common CNS-specific TRAEs included dysgeusia (24%) and dizziness (20%). Adagrasib demonstrated an IC objective response rate of 42%, disease control rate of 90%, progression-free survival of 5.4 months, and median overall survival of 11.4 months. Adagrasib is the first KRASG12C inhibitor to prospectively demonstrate IC activity in patients with KRASG12C-mutated NSCLC and untreated CNS metastases, supporting further investigation in this population.

Hypoxia-induced TMTC3 expression in esophageal squamous cell carcinoma potentiates tumor angiogenesis through Rho GTPase/STAT3/VEGFA pathway

BACKGROUND

Hypoxia is one of most typical features in the tumor microenvironment of solid tumor and an inducer of endoplasmic reticulum (ER) stress, and HIF-1α functions as a key transcription factor regulator to promote tumor angiogenesis in the adaptive response to hypoxia. Increasing evidence has suggested that hypoxia plays an important regulatory role of ER homeostasis. We previously identified TMTC3 as an ER stress mediator under nutrient-deficiency condition in esophageal squamous cell carcinoma (ESCC), but the molecular mechanism in hypoxia is still unclear.

METHODS

RNA sequencing data of TMTC3 knockdown cells and TCGA database were analyzed to determine the association of TMTC3 and hypoxia. Moreover, ChIP assay and dual-luciferase reporter assay were performed to detect the interaction of HIF-1α and TMTC3 promoter. In vitro and in vivo assays were used to investigate the function of TMTC3 in tumor angiogenesis. The molecular mechanism was determined using co-immunoprecipitation assays, immunofluorescence assays and western blot. The TMTC3 inhibitor was identified by high-throughput screening of FDA-approved drugs. The combination of TMTC3 inhibitor and cisplatin was conducted to confirm the efficiency in vitro and in vivo.

RESULTS

The expression of TMTC3 was remarkably increased under hypoxia and regulated by HIF-1α. Knockdown of TMTC3 inhibited the capability of tumor angiogenesis and ROS production in ESCC. Mechanistically, TMTC3 promoted the production of GTP through interacting with IMPDH2 Bateman domain. The activity of Rho GTPase/STAT3, regulated by cellular GTP levels, decreased in TMTC3 knockdown cells, whereas reversed by IMPDH2 overexpression. Additionally, TMTC3 regulated the expression of VEGFA through Rho GTPase/STAT3 pathway. Allopurinol inhibited the expression of TMTC3 and further reduced the phosphorylation and activation of STAT3 signaling pathway in a dose-dependent manner in ESCC. Additionally, the combination of allopurinol and cisplatin significantly inhibited the cell viability in vitro and tumor growth in vivo, comparing with single drug treatment, respectively.

CONCLUSIONS

Collectively, our study clarified the molecular mechanism of TMTC3 in regulating tumor angiogenesis and highlighted the potential therapeutic combination of TMTC3 inhibitor and cisplatin, which proposed a promising strategy for the treatment of ESCC.

Targeted nanodelivery of siRNA against KRAS G12D inhibits pancreatic cancer

Pancreatic cancer (PC) stands as a most deadly malignancy due to few effective treatments in the clinics. KRAS G12D mutation is a major driver for most PC cases, and silencing of KRAS G12D is considered as a potential therapeutic strategy for PC, which is nevertheless crippled by lacking a pragmatic delivery system for siRNA against KRAS G12D (siKRAS). Here, we report that cRGD peptide-modified bioresponsive chimaeric polymersomes (cRGD-BCP) mediate highly efficient siKRAS delivery to PANC-1 tumor, potently silencing KRAS G12D mRNA in tumor cells and effectively suppressing PC tumor growth in mice. cRGD-BCP exhibited remarkable encapsulation of siKRAS (loading content > 14 wt.%, loading efficiency > 90%) to form stable and uniform (ca. 68 nm) nanovesicles (cRGD-BCP-siKRAS). Of note, cRGD density greatly impacted the cellular uptake and silencing efficiency of cRGD-BCP-siKRAS in PANC-1 cells, in which an optimal cRGD density of 15.7 mol.% achieved 3.7- and 3.6-fold enhancement of internalization and gene silencing, respectively, compared with non-targeted BCP-siKRAS. cRGD-BCP-siKRAS was practically intact after 3-week storage at 4°C. Intriguingly, cRGD-BCP-siKRAS markedly enhanced the uptake of siKRAS in PANC-1 tumor, and at a siKRAS dose of 3 mg/kg knocked down 90% KRAS G12D gene, resulting in potent tumor inhibition and extraordinary survival benefits (median survival time: 101 days versus 38 (PBS group) and 59 days (BCP-siKRAS)) with 40% mice achieved complete regression. It appears that cRGD-mediated nanodelivery of siKRAS provides a potential cure for pancreatic cancer. STATEMENT OF SIGNIFICANCE: Small interfering RNA (siRNA) emerges as a specific and powerful biopharmaceuticals against cancers; however, inefficient in vivo delivery impedes its clinical translation. In spite of the fact that KRAS G12D mutation has been identified as a major driver for most pancreatic cancer, its notorious non-druggability renders little success on development of molecular targeted drugs. Pancreatic cancer is deemed as current king-of-cancer. Here, we show that cyclic RGD peptide installed bioresponsive polymersomes are able to efficiently deliver siRNA against KRAS G12D to pancreatic tumor, resulting in 90% gene knock-down and effective tumor inhibition. Strikingly, two out of five mice have been cured. This targeted nanodelivery of siRNA provides a high-efficacy treatment strategy for pancreatic cancer.

Adagrasib in Advanced Solid Tumors Harboring a KRASG12C Mutation

PURPOSE

Adagrasib, a KRASG12C inhibitor, has demonstrated clinical activity in patients with KRASG12C-mutated non-small-cell lung cancer (NSCLC) and colorectal cancer (CRC). KRASG12C mutations occur rarely in other solid tumor types. We report evaluation of the clinical activity and safety of adagrasib in patients with other solid tumors harboring a KRASG12C mutation.

METHODS

In this phase II cohort of the KRYSTAL-1 study (ClinicalTrials.gov identifier: NCT03785249; phase Ib cohort), we evaluated adagrasib (600 mg orally twice daily) in patients with KRASG12C-mutated advanced solid tumors (excluding NSCLC and CRC). The primary end point was objective response rate. Secondary end points included duration of response, progression-free survival (PFS), overall survival, and safety.

RESULTS

As of October 1, 2022, 64 patients with KRASG12C-mutated solid tumors were enrolled and 63 patients treated (median follow-up, 16.8 months). The median number of prior lines of systemic therapy was 2. Among 57 patients with measurable disease at baseline, objective responses were observed in 20 (35.1%) patients (all partial responses), including 7/21 (33.3%) responses in pancreatic and 5/12 (41.7%) in biliary tract cancers. The median duration of response was 5.3 months (95% CI, 2.8 to 7.3) and median PFS was 7.4 months (95% CI, 5.3 to 8.6). Treatment-related adverse events (TRAEs) of any grade were observed in 96.8% of patients and grade 3-4 in 27.0%; there were no grade 5 TRAEs. TRAEs did not lead to treatment discontinuation in any patients.

CONCLUSION

Adagrasib demonstrates encouraging clinical activity and is well tolerated in this rare cohort of pretreated patients with KRASG12C-mutated solid tumors.

Advanced in vitro models for renal cell carcinoma therapy design

Renal cell carcinoma (RCC) and its principal subtype, clear cell RCC, are the most diagnosed kidney cancer. Despite substantial improvement over the last decades, current pharmacological intervention still fails to achieve long-term therapeutic success. RCC is characterized by a high intra- and inter-tumoral heterogeneity and is heavily influenced by the crosstalk of the cells composing the tumor microenvironment, such as cancer-associated fibroblasts, endothelial cells and immune cells. Moreover, multiple physicochemical properties such as pH, interstitial pressure or oxygenation may also play an important role. These elements are often poorly recapitulated in in vitro models used for drug development. This inadequate recapitulation of the tumor is partially responsible for the current lack of an effective and curative treatment. Therefore, there are needs for more complex in vitro or ex vivo drug screening models. In this review, we discuss the current state-of-the-art of RCC models and suggest strategies for their further development.

Remodeling the tumor immune microenvironment via siRNA therapy for precision cancer treatment

How to effectively transform the pro-oncogenic tumor microenvironments (TME) surrounding a tumor into an anti-tumoral never fails to attract people to study. Small interfering RNA (siRNA) is considered one of the most noteworthy research directions that can regulate gene expression following a process known as RNA interference (RNAi). The research about siRNA delivery targeting tumor cells and TME has been on the rise in recent years. Using siRNA drugs to silence critical proteins in TME was one of the most efficient solutions. However, the manufacture of a siRNA delivery system faces three major obstacles, i.e., appropriate cargo protection, accurately targeted delivery, and site-specific cargo release. In the following review, we summarized the pharmacological actions of siRNA drugs in remolding TME. In addition, the delivery strategies of siRNA drugs and combination therapy with siRNA drugs to remodel TME are thoroughly discussed. In the meanwhile, the most recent advancements in the development of all clinically investigated and commercialized siRNA delivery technologies are also presented. Ultimately, we propose that nanoparticle drug delivery siRNA may be the future research focus of oncogene therapy. This summary offers a thorough analysis and roadmap for general readers working in the field.

Druggability of Targets for Diagnostic Radiopharmaceuticals

Targets play an indispensable and pivotal role in the development of radiopharmaceuticals. However, the initial stages of drug discovery projects are often plagued by frequent failures due to inadequate information on druggability and suboptimal target selection. In this context, we aim to present a comprehensive review of the factors that influence target druggability for diagnostic radiopharmaceuticals. Specifically, we explore the crucial determinants of target specificity, abundance, localization, and positivity rate and their respective implications. Through a detailed analysis of existing protein targets, we elucidate the significance of each factor. By carefully considering and balancing these factors during the selection of targets, more efficacious and targeted radiopharmaceuticals are expected to be designed for the diagnosis of a wide range of diseases in the future.

The potential role of miRNAs in the pathogenesis of testicular germ cell tumors - A Focus on signaling pathways interplay

Testicular germ cell tumors (TGCTs) are the most common testicular neoplasms in adolescents and young males. Understanding the genetic basis of TGCTs represents a growing need to cope with the increased incidence of these neoplasms. Although the cure rates have been comparatively increased, investigation of mechanisms underlying the incidence, progression, metastasis, recurrence, and therapy resistance is still necessary. Early diagnosis and non-compulsory clinical therapeutic agents without long-term side effects are now required to reduce the cancer burden, especially in the younger age groups. MicroRNAs (miRNAs) control an extensive range of cellular functions and exhibit a pivotal action in the development and spreading of TGCTs. Because of their dysregulation and disruption in function, miRNAs have been linked to the malignant pathophysiology of TGCTs by influencing many cellular functions involved in the disease. These biological processes include increased invasive and proliferative perspective, cell cycle dysregulation, apoptosis disruption, stimulation of angiogenesis, epithelial-mesenchymal transition (EMT) and metastasis, and resistance to certain treatments. Herein, we present an up-to-date review of the biogenesis of miRNAs, miRNA regulatory mechanisms, clinical challenges, and therapeutic interventions of TGCTs, and role of nanoparticles in the treatment of TGCTs.

A Chamber-Based Digital PCR Based on a Microfluidic Chip for the Absolute Quantification and Analysis of KRAS Mutation

The Kirsten rat sarcoma virus gene (KRAS) is the most common tumor in human cancer, and KRAS plays an important role in the growth of tumor cells. Normal KRAS inhibits tumor cell growth. When mutated, it will continuously stimulate cell growth, resulting in tumor development. There are currently few drugs that target the KRAS gene. Here, we developed a microfluidic chip. The chip design uses parallel fluid channels combined with cylindrical chamber arrays to generate 20,000 cylindrical microchambers. The microfluidic chip designed by us can be used for the microsegmentation of KRAS gene samples. The thermal cycling required for the PCR stage is performed on a flat-panel instrument and detected using a four-color fluorescence system. "Glass-PDMS-glass" sandwich structure effectively reduces reagent volatilization; in addition, a valve is installed at the sample inlet and outlet on the upper layer of the chip to facilitate automatic control. The liquid separation performance of the chip was verified by an automated platform. Finally, using the constructed KRAS gene mutation detection system, it is verified that the chip has good application potential for digital polymerase chain reaction (dPCR). The experimental results show that the chip has a stable performance and can achieve a dynamic detection range of four orders of magnitude and a gene mutation detection of 0.2%. In addition, the four-color fluorescence detection system developed based on the chip can distinguish three different KRAS gene mutation types simultaneously on a single chip.

D-1553 (Garsorasib), a Potent and Selective Inhibitor of KRASG12C in Patients With NSCLC: Phase 1 Study Results

INTRODUCTION

D-1553 (garsorasib) is a potent and selective oral KRASG12C inhibitor. We report results from a phase I dose-escalation and dose-expansion study of D-1553 in patients with KRAS G12C-mutated NSCLC in multiple sites in the People's Republic of China.

METHODS

Patients with KRAS G12C-mutated NSCLC have administrated D-1553 600 mg orally once daily, 800 mg once daily, 1200 mg once daily, 400 mg twice a day, or 600 mg twice a day in dose escalation. In dose-expansion, all patients received 600 mg twice a day. The safety, pharmacokinetics, and efficacy of D-1553 were evaluated.

RESULTS

Among a total of 79 treated patients, 75 patients (94.9%) reported treatment-related adverse events with 30 patients experiencing grade 3 or 4 events (38.0%). Most of the adverse events were manageable and the patients tolerated the study treatment well. Among 74 patients assessable for efficacy analysis, 30 patients had a partial response and 38 had stable disease with a confirmed objective response rate (ORR) and disease control rate (DCR) of 40.5% and 91.9%, respectively. The median progression-free survival was 8.2 months, and the median duration of response was 7.1 months. Among 62 patients assessable for response at the recommended phase 2 dose, partial response occurred in 24 patients (ORR, 38.7%) and stable disease in 32 patients (DCR, 90.3%). The median progression-free survival and duration of response were 7.6 months and 6.9 months, respectively. In patients with brain metastasis, ORR and DCR were 17% and 100%, respectively.

CONCLUSIONS

D-1553 represents a promising therapeutic option for patients with KRAS G12C-mutated NSCLC with a well-tolerated safety profile and encouraging antitumor activity.

Efficacy and toxicity of drugs targeting KRASG12C mutation in non-small cell lung cancer: a meta-analysis

OBJECTIVE

To systematically analyze the efficacy and toxicity of drugs targeting KRASG12C mutation in non-small cell lung cancer (NSCLC).

METHODS

The candidate studies were identified in PubMed, Embase, Cochrane Library, CNKI, and Wanfang databases up to 1 June 2023. Data on efficacy, prognosis, and adverse events (AEs) were extracted and calculated by meta-analysis.

RESULTS

Six eligible prospective studies were included in this meta-analysis, including 563 patients with advanced or metastatic NSCLC. For patients with NSCLC, the objective response rate (ORR) of drugs targeting KRASG12C mutation was 37% (95%CI 31-43), median duration of response (DOR) was 8.89 months (95%CI 7.96-9.83), and median progression-free survival (PFS) was 6.40 months (95%CI 5.86-6.93). The overall incidence of AEs was 88% (95%CI 79-96) and the incidence of grade ≥3 AEs was 44% (95%CI 24-64). The most common AEs were diarrhea, nausea, fatigue, and vomiting. The most common grade ≥3 AEs were Alaninetransaminase (ALT) or Aspartatetransaminase (AST) increased and diarrhea.

CONCLUSION

Sotorasib, Adagrasib, and Garsorasib as the drugs of choice for patients with KRASG12C mutation NSCLC, have definite efficacy and acceptable safety, especially for patients with advanced or metastatic disease and within posterior line therapy.

Identification of SERPINA1 promoting better prognosis in papillary thyroid carcinoma along with Hashimoto's thyroiditis through WGCNA analysis

Background

Hashimoto's thyroiditis (HT) is an autoimmune thyroid disease. Papillary thyroid carcinoma (PTC) is the most common endocrine cancer. In recent years the rate of coexistence between PTC and HT has increased but the relationship between them remains unclear, meaning it is necessary to find potential biomarkers for PTC coexistence with HT to predict its potential pathways.

Method

A co-expression network was constructed using the weighted gene co-expression network analysis (WGCNA) in the R package. The modules of PTC associated with HT (PTC-W) were identified from the GSE138198 dataset. Protein-protein interaction network (PPI) was used to screen the hub genes. Immunohistochemical (IHC) analysis was performed to validate the expression of the hub genes in tissues. Clinical data from The Cancer Genome Atlas (TCGA) datasets were used to analyse the prognosis of the hub genes. Gene set enrichment analysis (GSEA) was used to screen potential pathways of PTC-W.

Result

The MEbrown module representing the most significant module, with 958 differentially expressed genes (DEGs), was screened in PTC-W, based on WGCNA analysis. Through PPI, SERPINA1 was identified as a hub gene. Immunostaining validated that SERPINA1 was highly expressed in PTC-W. Moreover, PTC-W expressing SERPINA1 exhibits a better prognosis than PTC without HT (PTC-WO).

Conclusion

Our study demonstrates that SERPINA1 promotes the occurrence of PTC-W, and its prognosis is better than PTC-WO. SERPINA1 promotes a better prognosis for PTC-W, possibly through a tumour inhibition signalling pathway.

Inhalable siRNA Nanoparticles for Enhanced Tumor-Targeting Treatment of KRAS-Mutant Non-Small-Cell Lung Cancer

Kirsten rat sarcoma (KRAS) is the most commonly mutated oncogene in lung cancers. Gene therapy is emerging as a promising cancer treatment modality; however, the systemic administration of gene therapy has been limited by inefficient delivery to the lungs and systemic toxicity. Herein, we report a noninvasive aerosol inhalation nanoparticle (NP) system, termed "siKRAS@GCLPP NPs," to treat KRAS-mutant non-small-cell lung cancer (NSCLC). The self-assembled siKRAS@GCLPP NPs are capable of maintaining structural integrity during nebulization, with preferential distribution within the tumor-bearing lung. Inhalable siKRAS@GCLPP NPs show not only significant tumor-targeting capability but also enhanced antitumor activity in an orthotopic mouse model of human KRAS-mutant NSCLC. The nebulized delivery of siKRAS@GCLPP NPs demonstrates potent knockdown of mutated KRAS in tumor-bearing lungs without causing any observable adverse effects, exhibiting a better biosafety profile than the systemic delivery approach. The results present a promising inhaled gene therapy approach for the treatment of KRAS-mutant NSCLC and other respiratory diseases.

Paralog-based synthetic lethality: rationales and applications

Tumor cells can result from gene mutations and over-expression. Synthetic lethality (SL) offers a desirable setting where cancer cells bearing one mutated gene of an SL gene pair can be specifically targeted by disrupting the function of the other genes, while leaving wide-type normal cells unharmed. Paralogs, a set of homologous genes that have diverged from each other as a consequence of gene duplication, make the concept of SL feasible as the loss of one gene does not affect the cell's survival. Furthermore, homozygous loss of paralogs in tumor cells is more frequent than singletons, making them ideal SL targets. Although high-throughput CRISPR-Cas9 screenings have uncovered numerous paralog-based SL pairs, the unclear mechanisms of targeting these gene pairs and the difficulty in finding specific inhibitors that exclusively target a single but not both paralogs hinder further clinical development. Here, we review the potential mechanisms of paralog-based SL given their function and genetic combination, and discuss the challenge and application prospects of paralog-based SL in cancer therapeutic discovery.

RAS-targeted cancer therapy: Advances in drugging specific mutations

Rat sarcoma (RAS), as a frequently mutated oncogene, has been studied as an attractive target for treating RAS-driven cancers for over four decades. However, it is until the recent success of kirsten-RAS (KRAS)^G12C inhibitor that RAS gets rid of the title "undruggable". It is worth noting that the therapeutic effect of KRAS^G12C inhibitors on different RAS allelic mutations or even different cancers with KRAS^G12C varies significantly. Thus, deep understanding of the characteristics of each allelic RAS mutation will be a prerequisite for developing new RAS inhibitors. In this review, the structural and biochemical features of different RAS mutations are summarized and compared. Besides, the pathological characteristics and treatment responses of different cancers carrying RAS mutations are listed based on clinical reports. In addition, the development of RAS inhibitors, either direct or indirect, that target the downstream components in RAS pathway is summarized as well. Hopefully, this review will broaden our knowledge on RAS-targeting strategies and trigger more intensive studies on exploiting new RAS allele-specific inhibitors.

Erianin inhibits the growth and metastasis through autophagy-dependent ferroptosis in KRASG13D colorectal cancer

Colorectal cancer (CRC) is the third most common cause of cancer mortality worldwide. Approximately 40% of CRC patients are KRAS sequence variation, including KRAS G13D mutation (KRAS^G13D) CRC patients, accounting for approximately 8% of all KRAS mutations in CRC patients and showing little benefit from anti-EGFR therapy. Therefore, there is an urgent need for new and effective anticancer agents in patients with KRAS^G13D CRC. Here, we identified a natural product, erianin, that directly interacted with purified recombinant human KRAS^G13D with a Kd of 1.1163 μM, which also significantly improve the thermal stability of KRAS^G13D. The cell viability assay showed that KRAS^G13D cells were more sensitive to erianin than KRAS^WT or KRAS^G12V cells. In vitro, results showed that erianin suppressed the migration, invasion and epithelial-mesenchymal transition (EMT) of KRAS^G13D CRC cells. Furthermore, erianin induced ferroptosis, as evidenced by the accumulation of Fe²⁺ and reactive oxygen species (ROS), lipid peroxidation, and changes in the mitochondrial morphology of KRAS^G13D CRC cells. Interestingly, we also found that erianin-induced ferroptosis was accompanied by autophagy. Moreover, the occurrence of erianin-induced ferroptosis is reversed by autophagy inhibitors (NH4Cl and Bafilomycin A1) and ATG5 knockdown, suggesting that erianin-induced ferroptosis is autophagy-dependent. In addition, we evaluated the inhibition of tumor growth and metastasis by erianin in vivo using a subcutaneous tumor model and a spleen-liver metastasis model, respectively. Collectively, these data provide novel insights into the anticancer activity of erianin, which is valuable for the further discussion and investigation of the use of erianin in clinical anticancer chemotherapy for KRAS^G13D CRC.

Proteolysis-targeting chimeras in biotherapeutics: Current trends and future applications

The success of inhibitor-based therapeutics is largely constrained by the acquisition of therapeutic resistance, which is partially driven by the undruggable proteome. The emergence of proteolysis targeting chimera (PROTAC) technology, designed for degrading proteins involved in specific biological processes, might provide a novel framework for solving the above constraint. A heterobifunctional PROTAC molecule could structurally connect an E3 ubiquitin ligase ligand with a protein of interest (POI)-binding ligand by chemical linkers. Such technology would result in the degradation of the targeted protein via the ubiquitin-proteasome system (UPS), opening up a novel way of selectively inhibiting undruggable proteins. Herein, we will highlight the advantages of PROTAC technology and summarize the current understanding of the potential mechanisms involved in biotherapeutics, with a particular focus on its application and development where therapeutic benefits over classical small-molecule inhibitors have been achieved. Finally, we discuss how this technology can contribute to developing biotherapeutic drugs, such as antivirals against infectious diseases, for use in clinical practices.

Targeting PI3Kα overcomes resistance to KRasG12C inhibitors mediated by activation of EGFR and/or IGF1R

Although several KRasG12C inhibitors have displayed promising efficacy in clinical settings, acquired resistance developed rapidly and circumvented the activity of KRasG12C inhibitors. To explore the mechanism rendering acquired resistance to KRasG12C inhibitors, we established a series of KRASG12C-mutant cells with acquired resistance to AMG510. We found that differential activation of receptor tyrosine kinases (RTKs) especially EGFR or IGF1R rendered resistance to AMG510 in different cellular contexts by maintaining the activation of MAPK and PI3K signaling. Simultaneous inhibition of EGFR and IGF1R restored sensitivity to AMG510 in resistant cells. PI3K integrates signals from multiple RTKs and the level of phosphorylated AKT was revealed to negatively correlate with the anti-proliferative activity of AMG510 in KRASG12C-mutant cells. Concurrently treatment of a novel PI3Kα inhibitor CYH33 with AMG510 exhibited a synergistic effect against parental and resistant KRASG12C-mutant cells in vitro and in vivo, which was accompanied with concomitant inhibition of AKT and MAPK signaling. Taken together, these findings revealed the potential mechanism rendering acquired resistance to KRasG12C inhibitors and provided a mechanistic rationale to combine PI3Kα inhibitors with KRasG12C inhibitors for therapy of KRASG12C-mutant cancers in future clinical trials.

USP38 inhibits colorectal cancer cell proliferation and migration via downregulating HMX3 ubiquitylation

Accumulating evidence has shown that H6 Family Homeobox 3 (HMX3) plays a crucial role in nervous system regulation. However, the regulatory mechanism of HMX3 in colorectal cancer (CRC) has seldom been studied. Herein, HMX3 was significantly downregulated in CRC, as demonstrated by qRT-PCR and WB analysis on clinical samples and a panel of cell lines. Besides, it was found that the expression of HMX3 was negatively correlated with survival of CRC patients. The functional analyses (EdU staining, CCK-8, colony formation, Transwell, and wound scratch assays) showed that CRC cell proliferation, migration, and invasion were significantly suppressed by HMX3 overexpression, while enhanced by HMX3 knockdown. Moreover, in vivo experiment revealed HMX3 overexpression could also suppress tumor growth. Combining bioinformatics and WB analysis, we preliminarily uncovered that HMX3 was involved in apoptosis and KRAS signaling pathways. Mechanistically, Ubiquitin-specific protease 38 (USP38) was identified as a novel post-translational regulator of HMX3, which could directly interact with HMX3 to stabilize its protein expression via deubiquitination. Furthermore, the role of USP38 silencing in promoting cell proliferation, migration, and invasion of CRC cells was blocked by HMX3 overexpression. In conclusion, our findings suggested that USP38/HMX3 axis is a novel promising therapeutic candidate for CRC.

Breaking the Mold: Epigenetics and Genomics Approaches Addressing Novel Treatments and Chemoresponse in TGCT Patients

Testicular germ-cell tumors (TGCT) have been widely recognized for their outstanding survival rates, commonly attributed to their high sensitivity to cisplatin-based therapies. Despite this, a subset of patients develops cisplatin resistance, for whom additional therapeutic options are unsuccessful, and ~20% of them will die from disease progression at an early age. Several efforts have been made trying to find the molecular bases of cisplatin resistance. However, this phenomenon is still not fully understood, which has limited the development of efficient biomarkers and precision medicine approaches as an alternative that could improve the clinical outcomes of these patients. With the aim of providing an integrative landscape, we review the most recent genomic and epigenomic features attributed to chemoresponse in TGCT patients, highlighting how we can seek to combat cisplatin resistance through the same mechanisms by which TGCTs are particularly hypersensitive to therapy. In this regard, we explore ongoing treatment directions for resistant TGCT and novel targets to guide future clinical trials. Through our exploration of recent findings, we conclude that epidrugs are promising treatments that could help to restore cisplatin sensitivity in resistant tumors, shedding light on potential avenues for better prognosis for the benefit of the patients.