Rat Sarcoma Viral Oncogene Homolog Research Articles

Potent antitumor activity of a bispecific T-cell engager antibody targeting the intracellular antigen KRAS G12V.

Kirsten Rat Sarcoma viral oncogene homolog (KRAS) is one of the most frequent oncogenes. However, there are limited treatment options due to its intracellular expression. To address this, we developed a novel bispecific T-cell engager (BiTE) antibody targeting HLA-A2/KRAS G12V complex and CD3 (HLA-G12V/CD3 BiTE). We examined its specific binding to tumor cells and T cells, as well as its anti-tumor effects in vivo. HLA-G12V/CD3 BiTE was expressed in Escherichia coli and its binding affinities to CD3 and HLA-A2/KRAS G12V were measured by flow cytometry, along with T-cell activation. In a xenograft pancreatic tumor model, the HLA-G12V/CD3 BiTE's anti-tumor effects were assessed through tumor growth, survival time, and safety. Our results demonstrated specific binding of HLA-G12V/CD3 BiTE to tumor cells with an HLA-A2/KRAS G12V mutation and T cells. The HLA-G12V/CD3 BiTE also activated T-cells in the presence of tumor cells in vitro. HLA-G12V/CD3 BiTE in vivo testing showed delayed tumor growth without severe toxicity to major organs and prolonged mouse survival. This study highlights the potential of constructing BiTEs recognizing an HLA-peptide complex and providing a novel therapy for cancer treatment targeting the intracellular tumor antigen.

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.

RAF and MEK Inhibitors in Non-Small Cell Lung Cancer.

Lung cancer, despite recent advancements in survival rates, represents a significant global health burden. Non-small cell lung cancer (NSCLC), the most prevalent type, is driven largely by activating mutations in Kirsten rat sarcoma viral oncogene homologue (KRAS) and receptor tyrosine kinases (RTKs), and less in v-RAF murine sarcoma viral oncogene homolog B (BRAF) and mitogen-activated protein-kinase kinase (MEK), all key components of the RTK-RAS-mitogen-activated protein kinase (MAPK) pathway. Learning from melanoma, the identification of BRAFV600E substitution in NSCLC provided the rationale for the investigation of RAF and MEK inhibition as a therapeutic strategy. The regulatory approval of two RAF-MEK inhibitor combinations, dabrafenib-trametinib, in 2017, and encorafenib-binimetinib, in 2023, signifies a breakthrough for the management of BRAFV600E-mutant NSCLC patients. However, the almost universal emergence of acquired resistance limits their clinical benefit. New RAF and MEK inhibitors, with distinct biochemical characteristics, are in preclinical and clinical development. In this review, we aim to provide valuable insights into the current state of RAF and MEK inhibition in the management of NSCLC, fostering a deeper understanding of the potential impact on patient outcomes.

An odd dancing couple. Non-small cell lung carcinoma with coexisting EGFR mutation and NTRK-1 translocation: A case report.

In the 21st century, there has been a dramatic shift in the diagnosis and management of non-small cell lung carcinoma (NSCLC), with an increasing use of minimally invasive tissue acquisition methods. Current treatments require morphologic subtyping and biomarker information in all cases. Determining such biomarkers is a continuously evolving field; current guidelines state that the determination of mutations on the Epidermal Growth Factor (EFGR), Kirsten Rat Sarcoma viral oncogene homolog (KRAS), Proto-oncogene B-Raf (BRAF), Human epidermal growth factor receptor 2 (HER2) and Anaplastic Lymphoma Kinase (ALK), genes as well as fusions on genes such as ROS Proto-Oncogene 1, Receptor Tyrosine Kinase (ROS1), MET proto-oncogene, receptor tyrosine kinase (MET), RET proto-oncogene (RET), and the Neurotrophic Tyrosine Receptor Kinase (NTRK) family is mandatory. While analyzing such alterations, some of them were first reported to be mutually exclusive, although in recent years, it has been shown otherwise in some of these cases. Moreover, so was the case with the concomitant expression of NTRK fusions and EGFR mutations. We present a case report of a patient with concomitant EGFR mutation and NTRK1 fusion.

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.

Temporal trends and regional variability in BRAF and KRAS genetic testing in Denmark (2010-2022): Implications for precision medicine.

This study aims to evaluate the developments in the testing of Kirsten Rat Sarcoma viral oncogene homolog (KRAS) and v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) mutations across different cancer types and regions in Denmark from 2010 to 2022. Using comprehensive data from the Danish health registries, we linked molecular test results from the Danish Pathology Registry with cancer diagnoses from the Danish National Patient Registry between 2010 and 2022. We assessed the frequency and distribution of KRAS and BRAF mutations across all cancer types, years of testing, and the five Danish regions. The study included records of KRAS testing for 30 671 patients and BRAF testing for 30 860 patients. Most KRAS testing was performed in colorectal (78%) and lung cancer (18%), and BRAF testing in malignant melanoma (13%), colorectal cancer (67%), and lung cancer (12%). Testing rates and documentation mutational subtypes increased over time. Reporting of wildtype results varied between lung and colorectal cancer, with underreporting in lung cancer. Regional variations in testing and reporting were observed. Our study highlights substantial progress in KRAS and BRAF testing in Denmark from 2010 to 2022, evidenced by increased and more specific reporting of mutational test results, thereby improving the precision of cancer diagnosis and treatment. However, persistent regional variations and limited testing for cancer types beyond melanoma, colorectal, and lung cancer highlight the necessity for a nationwide assessment of the optimal testing approach.

Characteristics and outcomes of large (≥5 cm) colonic adenocarcinomas and comparing outcomes of minimally invasive and open surgery for stage I to III disease

BackgroundColon cancer prognosis is primarily dependent on the stage at diagnosis, but tumor size and location may also impact prognosis. This study aimed to assess the characteristics and outcomes of patients with ≥5 cm colonic adenocarcinomas and compare outcomes of open and minimally invasive surgery for stage I to III large colonic adenocarcinomas. MethodsThe National Cancer Database (2010–2019) was searched for patients with colonic adenocarcinomas ≥5 cm. Outcomes of patients who underwent minimally invasive surgery or open surgery were compared after propensity-score matching. The primary outcome was 5-year overall survival and, secondarily, hospital stay, surgical margins, and short-term mortality. ResultsA total of 126,959 patients were included (22.1% of all diagnosed adenocarcinomas). 56% of tumors were right-sided, 32.6% were left-sided, and 11.4% were in the transverse colon. Stage IV disease was recorded in 34.6% of patients. Lymphovascular invasion, perineural invasion, and Kirsten rat sarcoma viral oncogene homolog mutations were recorded in 35.7%, 14.9%, and 41.6% of patients. The rate of positive surgical margins was 9.8%. Median hospital stay was 6 (interquartile range: 4–8) days. 30- and 90-day mortality rates were 4.1% and 7.5%, respectively. After matching, 15,228 patients in the open surgery group were matched to a similar number in the minimally invasive surgery group. The minimally invasive surgery group was associated with significantly lower rates of 30- and 90-day mortality, positive surgical margins, shorter hospital stay, and longer median overall survival (110.6 vs 86.6 months, P < .001) than did open surgery. ConclusionLarge colonic adenocarcinomas are mostly right-sided or transverse and present at a more advanced stage with adverse pathologic features. Minimally invasive surgery was associated with better overall survival and short-term benefits when compared with open surgery.

Red blood cells function as reservoirs of tumor DNA.

Novel screening techniques for early detection of lung cancer are urgently needed. Profiling circulating tumor cell-free DNA (ctDNA) has emerged as a promising tool for biopsy-free tumor genotyping. However, both the scarcity and short half-life of ctDNA substantially limit the sensitivity and clinical utility of ctDNA detection methodologies. Our discovery that red blood cells (RBCs) sequester mitochondrial DNA opens a new avenue for detecting circulating nucleic acids, as RBCs represent an unrecognized reservoir of circulating nucleic acid. Here, we show that RBCs acquire tumor DNA following coculture with lung cancer cell lines harboring Kirsten rat sarcoma viral oncogene homolog (KRAS) and epidermal growth factor receptor (EGFR) mutations. RBC-bound tumor DNA is detectable in patients with early-stage non-small cell lung cancer (NSCLC) but not in healthy controls by qPCR. Our results collectively uncover a previously unrecognized yet easily accessible reservoir of tumor DNA, offering a promising foundation for future RBC-based tumor diagnostics.NEW & NOTEWORTHY We present a novel method for lung cancer detection by revealing RBCs as a reservoir for tumor DNA, overcoming the limitations of current circulating tumor ctDNA methodologies. By demonstrating that RBCs can capture tumor DNA, including critical mutations found in lung cancer, we provide a promising, biopsy-free avenue for early cancer diagnostics. This discovery opens up exciting possibilities for developing RBC-based diagnostic tools, significantly enhancing the sensitivity and clinical utility of noninvasive cancer detection.

Abstract 5033: Sub-0.01% KRAS G12C dPCR variant detection by mutation specific blocker (MSB) cassettes

Abstract Purpose: Kirsten rat sarcoma viral oncogene homologue (KRAS) is one of the most well-known oncogenes and is found commonly mutated in numerous cancer subtypes. Despite its prevalence as a driver of disease state, until recently KRAS-targeting therapeutics have proven difficult to develop due to lack of specificity (Huang 2021). Now, several treatments have been approved for KRAS mutated cancers that are driven specifically by the G12C variant, and additional compounds are under investigation. Enrollment on these therapies is conditional on the G12C mutation presence, and thus accurate, sensitive detection of G12C is critical. Herein, we describe the development of KRAS G12C-targeting MSB dPCR assays capable of detecting G12C variants down to less than 0.01% variant allele frequency in whole blood, FFPE, and cfDNA samples. Methods: Multiple KRAS G12C MSB cassettes were developed, composed of four components: a mutation-specific forward primer with an engineered penultimate nucleotide mismatch, a non-extendable blocking oligo for the wild-type (WT) KRAS G12 sequence, a TaqMan probe, and a standard reverse primer. Initial cassette performance was assessed using synthetic KRAS G12C and KRAS G12 WT sequences inserted into an IDT plasmid backbone and tested directly or spiked into whole blood or extracted genomic DNA obtained from healthy donors prior to testing. Data obtained with the MSB cassettes across multiple matrices was compared to a BioRad off-the-shelf KRAS G12C droplet digital PCR (ddPCR) assay for accuracy. Cassette designs achieving the desired specificity and sensitivity were subsequently run on cell-free DNA samples possessing KRAS G12C, KRAS G12D, and WT sequences to evaluate performance in patient material. Results: The enhanced WT suppression design of the assay allowed the lower limit of detection and limit of blank to remain at 6 copies/reaction (cps/rxn) and 3 cps/rxn, respectively, across 30 ng/rxn to 350 ng/rxn gDNA background. At the theoretical maximum input of 200,000 cps/rxn, the assay can achieve 0.003% frequency detection in a single well, with robust detection down to 5 ng/rxn input, making it ideal for samples with limited availability. The assay demonstrated high accuracy, with a correlation coefficient ≥ 0.95 to known values and the BioRad reference assay, and high precision, with less than 10% coefficient of variation among allele frequencies of the same sample. Conclusion: With the emergence of targeted therapies for KRAS G12C driven cancers, detection of this mutation has become crucial in the diagnosis. While multiple methods are available for variant identification, MSB cassettes represent a powerful approach to achieve a sensitivity of molecular detection not possible with other techniques. This enhanced sensitivity directly impacts patient access to potentially life-saving therapies, ensuring all possible options are available to diagnose the patients sensitively and early. Citation Format: Ashley Beams, Kevin Lee, Samantha Addison, Nathan Riccitelli. Sub-0.01% KRAS G12C dPCR variant detection by mutation specific blocker (MSB) cassettes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5033.

Abstract 4111: Multi-peptide cancer vaccines targeting KRAS induce significant anti-tumor efficacy

Abstract Background and objective: Kirsten rat sarcoma viral oncogene homologue (KRAS) is frequently mutated in human cancers. KRAS mutants offer the potential for the development of cancer-specific immunotherapy, as epitopes harbouring mutations are strong neoantigens to which the immune system generates cancer-specific anti-tumor effects. However, previous clinical trials of KRAS-targeted vaccines failed to generate satisfactory anti-cancer efficacy. Evidence suggested that CD4 T cell activity plays a critical role in augmenting the cytotoxic effect of CD8 T cells. Here, we design long peptides based on the MHC II hotspots on the entire KRAS protein that activate both CD4 and CD8 T cells to kill KRAS-driven cancer cells. Long peptides also cover a wider range of HLA alleles to increase their utility in a broader spectrum of patients. Our objective is to create a multi-peptide vaccine simultaneously targeting the mutant and wild-type (WT) regions of human KRAS protein. Methods: By selecting MHC II hotspots via multiple epitope prediction algorithms, we designed and synthesized 8 long peptides with lengths between 25 to 30mers. One of them harboured a G12D mutation, while the others covered the WT regions of KRAS. In addition, the corresponding keyhole limpet hemocyanin (KLH) conjugated peptides were also generated. We first demonstrated their immunogenicity in mouse in vivo models. Different combinations of peptides adjuvanted with either CpG oligodeoxynucleotide + aluminum (CpG+alum) or complete/incomplete Freud’s adjuvant (CFA/IFA) were immunized into Balb/c mice before determining the immune response by mouse interferon γ (mIFNγ) ELISPOT assay. Subsequently, an in vivo prophylactic anti-tumor study was conducted by immunizing this multi-peptide vaccine in Balb/c mice and observing the growth inhibition of the CT26-derived tumors. Results: T cell responses were observed in two peptide mixes with or without G12D mutation, suggesting that both mutant-harbouring peptide and WT peptides were immunogenic. We showed that KLH-conjugated peptides and CpG+alum elicited stronger immune responses than the naked peptides and CFA/IFA respectively. Furthermore, peptide mapping showed that the G12D mutant-harbouring peptide and two other WT peptides may contribute to the overall T cell response in the Balb/c mouse. In the prophylactic anti-tumor study (n = 10), immunization of KRAS naked peptide and KLH-conjugated peptide vaccines significantly inhibited tumor growth by 51.2% (****p &amp;lt; 0.0001) and 44.7% (***p &amp;lt; 0.001) respectively, compared to control. Subsequent mIFNγ ELISPOT assay showed that the tumor inhibitory effect was attributed to the activation of antigen-specific T cell response of the vaccines. Conclusion: Our multi-peptide vaccines targeting both the mutant and WT regions of KRAS could generate KRAS-specific T cell responses and elicit significant anti-tumor effect in mouse models. Citation Format: Chi Han Samson Li, Melvin Toh. Multi-peptide cancer vaccines targeting KRAS induce significant anti-tumor efficacy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4111.

Abstract 3941: Wild-type KRAS dosage in mutant KRAS lung cancer: Implications for tumorigenesis and therapeutic response

Abstract Lung adenocarcinomas (LUAD) are frequently driven by activating mutations in the Kirsten rat sarcoma viral oncogene homolog (KRAS). Previous studies have suggested that wild-type (wt)-RAS signaling may modulate cancer progression and drug resistance in these tumors. However, the interplay between oncogenic KRAS and wt-RAS-like GTPases in lung cancer biology and treatment remains debated. Here, we investigated the impact of increased wt-KRAS dosage in LUAD harboring mutant KRAS on lung cancer phenotypes and response to anti-KRAS therapies. Increased wt-KRAS dosage occurs in LUAD due to the loss of LZTR1, a proteostatic regulator of RAS-like GTPases. LZTR1 mutations, deletions, or downregulation co-occur with oncogenic KRAS mutations in more than 40% of LUAD patients. Using a global protein stability screen, we identified LZTR1 as the main regulator of the stability of wt-KRAS, but not of the oncogenic KRAS mutants. Proteomic analysis of LUAD cells confirmed that LZTR1 loss leads to elevated expression of wt-KRAS, but not of KRAS-G12D, indicating that LZTR1 loss affects wt-RAS rather than mutant KRAS signaling. LZTR1 loss in LUAD patients is associated with poor prognosis and hypoxic expression signatures. In a mouse model of Kras-mutated LUAD, Lztr1 haploinsufficiency promoted tumor initiation and progression. Moreover, Lztr1 loss results in hypoxic tumors with inflamed, tortuous, insufficiently perfused, and leaky vessels. Integrative proteomic and phosphoproteomic analysis revealed increased RAL/TBK1 pathway activity in LZTR1-depleted lung cancer cells and Lztr1-deleted tumors. This leads to enhanced secretion of proangiogenic and proinflammatory factors, such as VEGF and TNFα, by LZTR1-deficient cells and an increased number of neutrophils in Lztr1-deleted tumors. TNF-activated neutrophils present at vascular branching points can modulate vascular remodeling by influencing the formation and function of blood vessels. Pharmacological inhibition of RAL/TBK1 signaling with amlexanox, an anti-NF-κB/TBK1 drug, reduces TNFα secretion, decreases the number of neutrophils, and normalizes the tumor-associated vasculature. We demonstrated that increased wt-KRAS dosage, but not other small GTPases, mimicked the effects of LZTR1 loss on RAL/TBK1 signaling and VEGF secretion, suggesting that LZTR1 loss alters the heterogeneity of KRAS-mutated lung cancer by modulating wt-KRAS levels. Furthermore, MRTX1133 a selective inhibitor of KRAS-G12D, showed limited effect in the Kras-G12D, Lztr1-loss LUAD model, whereas the combination of MRTX1133 and amlexanox suppress tumor growth, likely due to the restoration of the tumor vasculature by RAL/TBK1 inhibition. Our study reveals novel insights into the role of wt-KRAS dosage in mutant KRAS lung cancer and identifies potential therapeutic strategies to target patients with dysregulated KRAS proteostasis due to LZTR1 loss. Citation Format: Tonci Ivanisevic, Greetje Vande Velde, Peihua Zhao, Wout Magits, Raj N. Sewduth, Anna A. Sablina. Wild-type KRAS dosage in mutant KRAS lung cancer: Implications for tumorigenesis and therapeutic response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3941.

Sotorasib (Lumakras)

&#x0D; CADTH recommends that public drug plans should not reimburse Lumakras for the treatment of adult patients with Kirsten rat sarcoma viral oncogene homologue (KRAS) G12C-mutated locally advanced (not amenable to curative therapy) or metastatic non–small cell lung cancer (NSCLC) who have received at least 1 prior systemic therapy.&#x0D; The clinical evidence reviewed by CADTH was insufficient to conclude that treatment with Lumakras results in a clinically meaningful delay in disease progression compared with docetaxel. It was impossible to assess whether treatment with Lumakras would prolong survival relative to docetaxel.&#x0D; Patients identified the need for more effective treatments that delay disease progression, prolong survival, control disease symptoms, improve quality of life, reduce side effects, and offer an oral route of administration. While Lumakras offers an oral route of administration, it is not clear whether Lumakras meets the other needs identified by patients.&#x0D;

Targeting KRAS G12C Mutation in Colorectal Cancer, A Review: New Arrows in the Quiver.

Kirsten rat sarcoma virus oncogene homolog (KRAS) is the most frequently mutated oncogene in human cancer. In colorectal cancer (CRC), KRAS mutations are present in more than 50% of cases, and the KRAS glycine-to-cysteine mutation at codon 12 (KRAS G12C) occurs in up to 4% of patients. This mutation is associated with short responses to standard chemotherapy and worse overall survival compared to non-G12C mutations. In recent years, several KRAS G12C inhibitors have demonstrated clinical activity, although all patients eventually progressed. The identification of negative feedback through the EGFR receptor has led to the development of KRAS inhibitors plus an anti-EGFR combination, thus boosting antitumor activity. Currently, several KRAS G12C inhibitors are under development, and results from phase I and phase II clinical trials are promising. Moreover, the phase III CodeBreaK 300 trial demonstrates the superiority of sotorasib-panitumumab over trifluridine/tipiracil, establishing a new standard of care for patients with colorectal cancer harboring KRAS G12C mutations. Other combinations such as adagrasib-cetuximab, divarasib-cetuximab, or FOLFIRI-panitumumab-sotorasib have also shown a meaningful response rate and are currently under evaluation. Nonetheless, most of these patients will eventually relapse. In this setting, liquid biopsy emerges as a critical tool to characterize the mechanisms of resistance, consisting mainly of acquired genomic alterations in the MAPK and PI3K pathways and tyrosine kinase receptor alterations, but gene fusions, histological changes, or conformational changes in the kinase have also been described. In this paper, we review the development of KRAS G12C inhibitors in colorectal cancer as well as the main mechanisms of resistance.

Haploinsufficiency of Adenomatous Polyposis Coli Coupled with Kirsten Rat Sarcoma Viral Oncogene Homologue Activation and P53 Loss Provokes High-Grade Glioblastoma Formation in Mice.

Glioblastoma multiforme (GBM) is the most common and deadly type of brain tumor originating from glial cells. Despite decades of clinical trials and research, there has been limited success in improving survival rates. However, molecular pathology studies have provided a detailed understanding of the genetic alterations associated with the formation and progression of glioblastoma-such as Kirsten rat sarcoma viral oncogene homolog (KRAS) signaling activation (5%), P53 mutations (25%), and adenomatous polyposis coli (APC) alterations (2%)-laying the groundwork for further investigation into the biological and biochemical basis of this malignancy. These analyses have been crucial in revealing the sequential appearance of specific genetic lesions at distinct histopathological stages during the development of GBM. To further explore the pathogenesis and progression of glioblastoma, here, we developed the glial-fibrillary-acidic-protein (GFAP)-Cre-driven mouse model and demonstrated that activated KRAS and p53 deficiencies play distinct and cooperative roles in initiating glioma tumorigenesis. Additionally, the combination of APC haploinsufficiency with mutant Kras activation and p53 deletion resulted in the rapid progression of GBM, characterized by perivascular inflammation, large necrotic areas, and multinucleated giant cells. Consequently, our GBM models have proven to be invaluable resources for identifying early disease biomarkers in glioblastoma, as they closely mimic the human disease. The insights gained from these models may pave the way for potential advancements in the diagnosis and treatment of this challenging brain tumor.

The effects of miR-217 inhibitor and mimic in the progression of Kirsten rat sarcoma viral oncogene homologue driven cancers

BackgroundKirsten rat sarcoma viral oncogene homologue (KRAS) is one of the most frequently mutated proto-oncogenes in approximately 90% of pancreatic ductal carcinoma (PDAC) and 45% of colorectal cancer (CC) cases. Studies in the past have identified microRNA-217 (miR-217) as a potential tumour-suppressing miRNA that is downregulated in various cancers. Using in silico prediction algorithms, several studies have identified miR-217 as a potential regulator of KRAS, and we investigated its role in PDAC and CC progression. MethodThe study was carried out in KRAS-driven cancer (KDC) cell lines PANC-1 (pancreatic cancer) and SW-480 (CC), which have mutant KRAS gene expression. The KDC cells are transfected with specific oligonucleotides for miR-217, anti-miR-217, and a negative control in serum-free media using lipofectamine. After fixing the IC50, using specific primers, gene expression studies were carried out by qPCR for KRAS downstream targets and genes associated with apoptosis and cell cycle. Anti-migration and anti-apoptotic effects were studied using the transwell migration assay and annexin-V/PI staining methods, and mitochondrial morphology was observed using a transmission electron microscope. ResultsThe present study demonstrates that overexpression of miR-217 in KDC cells mitigates proliferation and migration and promotes cell cycle arrest and apoptosis of KDC cells via the MAPK/ERK signalling pathway. Besides, decreased miR-217 expression rescues KDC cells from the effects mediated by KRAS downstream signalling. ConclusionThe outcome of the study indicates miR-217 suppresses tumour growth and promotes apoptosis in KDC and that these effects are associated with down regulation of MAPK/ERK signalling.

Effect of Strong CYP3A4 Inhibition, CYP3A4 Induction, and OATP1B1/3 Inhibition on the Pharmacokinetics of a Single Oral Dose of Sotorasib.

Sotorasib is a small molecule that irreversibly inhibits the Kirsten rat sarcoma viral oncogene homolog (KRAS) protein with a G12C amino acid substitution mutant protein. The impact of cytochrome P450 (CYP) 3A4 inhibition and induction on sotorasib pharmacokinetics (PKs) was evaluated in 2 separate studies in healthy volunteers (N = 14/study). The impact of CYP3A4 inhibition was interrogated utilizing repeat doses of 200mg of itraconazole, a strong CYP3A4 inhibitor, on 360mg of sotorasib PKs. The impact of CYP3A4 induction was interrogated utilizing multiple doses of 600mg of rifampin, a strong CYP3A4 inducer. Additionally, the impact of organic anion transporting polypeptide (OATP) 1B1/3 inhibition on 960mg of sotorasib PKs was interrogated after a single dose of 600mg of rifampin. CYP3A4 inhibition did not significantly impact sotorasib Cmax but did lead to a 26% increase in sotorasib AUCinf . CYP3A4 induction decreased sotorasib Cmax by 35% and AUCinf by 51%. OATP1B1/3 inhibition decreased sotorasib Cmax and AUCinf by 16% and 23%, respectively. These results support that sotorasib can be given together with strong CYP3A4 and OATP1B1/3 inhibitors but the co-administration of sotorasib and strong CYP3A4 inducers should be avoided.

Clinical characteristics, outcomes and prognostic factors in KRAS mutant lung cancers: experience from a tertiary care cancer center in India.

Kirsten rat sarcoma viral oncogene homologue (KRAS) mutations in lung cancers, long considered untargetable, have had a recent rise in interest due to promising data of agents targeting KRAS p.G12C. As Indian data are scarce, we sought to identify baseline clinical characteristics, prognostic factors and outcomes of lung cancer patients with KRAS mutations at our hospital. Patients with KRAS mutant lung cancers treated at our institute from 2016 to 2022 were analysed. 133 patients with KRAS mutant lung cancers were identified. Median age was 57 (interquartile range 28-78) years, and 58 (43.6%) were smokers. 17 (12.7%) had brain metastases. The commonest variant was p.G12C, seen in 53 (39.8%) patients. Six (4.5%) had programmed death ligand 1 (PDL-1) expression >50% by Ventana SP263 PDL-1 assay, and 13 (9.7%) had epidermal growth factor mutation. Of 92 patients with available treatment details, the majority received intravenous chemotherapy, nine (9.8%) received tyrosine kinase inhibitors and four (4.4%) received immunotherapy (pembrolizumab). Median progression-free survival (PFS) with first-line therapy was 6 (95% confidence interval (CI) 2.8-9.2) months and median overall survival (OS) was 12 (CI 9.2-14.8) months. The incidence of brain metastases was higher in patients with G12C mutations (p = 0.025). Brain metastases (HR: 3.57, p < 0.001), Eastern Cooperative Oncology Group performance status (PS) ≥ 2 (HR: 2.13, p = 0.002) and G12C mutation (HR: 1.84, p = 0.011) were associated with inferior PFS, while brain metastases (HR: 4.6, p < 0.001), PS ≥ 2 (HR: 2.33, p = 0.001) and G12C mutation (HR: 1.93, p = 0.01) were associated with inferior OS. This is the largest dataset of KRAS mutant lung cancers from India. Brain metastases were higher in patients with G12C mutations and associated with poorer PFS and OS. G12C mutation and PS ≥ 2 were also associated with inferior PFS and OS. Experience with targeted therapy for KRAS mutations remains an area of future exploration due to the unavailability of these agents in India.

Small-molecule inhibition of MAP2K4 is synergistic with RAS inhibitors in KRAS-mutant cancers

The Kirsten rat sarcoma viral oncogene homologue KRAS is among the most commonly mutated oncogenes in human cancers, thus representing an attractive target for precision oncology. The approval for clinical use of the first selective inhibitors of G12C mutant KRAS therefore holds great promise for cancer treatment. However, despite initial encouraging clinical results, the overall survival benefit that patients experience following treatment with these inhibitors has been disappointing to date, pointing toward the need to develop more powerful combination therapies. Here, we show that responsiveness to KRASG12C and pan-RAS inhibitors in KRAS-mutant lung and colon cancer cells is limited by feedback activation of the parallel MAP2K4-JNK-JUN pathway. Activation of this pathway leads to elevated expression of receptor tyrosine kinases that reactivate KRAS and its downstream effectors in the presence of drug. We find that the combination of sotorasib, a drug targeting KRASG12C, and the MAP2K4 inhibitor HRX-0233 prevents this feedback activation and is highly synergistic in a panel of KRASG12C-mutant lung and colon cancer cells. Moreover, combining HRX-0233 and sotorasib is well-tolerated and resulted in durable tumor shrinkage in mouse xenografts of human lung cancer cells, suggesting a therapeutic strategy for KRAS-driven cancers.

Quantitative peritumoral magnetic resonance imaging fingerprinting improves machine learning-based prediction of overall survival in colorectal cancer.

To investigate magnetic resonance imaging (MRI)-based peritumoral texture features as prognostic indicators of survival in patients with colorectal liver metastasis (CRLM). From 2007-2015, forty-eight patients who underwent MRI within 3 months prior to initiating treatment for CRLM were identified. Clinicobiological prognostic variables were obtained from electronic medical records. Ninety-four metastatic hepatic lesions were identified on T1-weighted post-contrast images and volumetrically segmented. A total of 112 radiomic features (shape, first-order, texture) were derived from a 10 mm region surrounding each segmented tumor. A random forest model was applied, and performance was tested by receiver operating characteristic (ROC). Kaplan-Meier analysis was utilized to generate the survival curves. Forty-eight patients (male:female = 23:25, age 55.3 years ± 18 years) were included in the study. The median lesion size was 25.73 mm (range 8.5-103.8 mm). Microsatellite instability was low in 40.4% (38/94) of tumors, with Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation detected in 68 out of 94 (72%) tumors. The mean survival was 35 months ± 21 months, and local disease progression was observed in 35.5% of patients. Univariate regression analysis identified 42 texture features [8 first order, 5 gray level dependence matrix (GLDM), 5 gray level run time length matrix (GLRLM), 5 gray level size zone matrix (GLSZM), 2 neighboring gray tone difference matrix (NGTDM), and 17 gray level co-occurrence matrix (GLCM)] independently associated with metastatic disease progression (P < 0.03). The random forest model achieved an area under the curve (AUC) of 0.88. MRI-based peritumoral heterogeneity features may serve as predictive biomarkers for metastatic disease progression and patient survival in CRLM.

Bilateral diffuse metastases in advanced lung adenocarcinoma harboring EGFR mutations was associated with a favorable prognosis to EGFR-TKIs.

Bilateral diffuse metastatic lung adenocarcinoma (BLDM-LUAD) is a special imaging pattern of lung adenocarcinoma (LUAD). We retrospectively assessed survival outcomes and co-mutation characteristics of BLDM-LUAD patients harboring epidermal growth factor receptor (EGFR) mutations who were treated with EGFR-yrosine kinase inhibitors (TKIs). From May 2016 to May 2021, among 458 patients who submitted samples for next generation sequencing (NGS) detection in 1125 patients with non-small-cell lung cancer (NSCLC), and 44 patients were diagnosed as BLDM-LUAD. In order to analyze the survival outcomes of BLDM-LUAD patients harboring EGFR mutations who were treated with EGFR-TKIs, the factors age, gender, smoking history, hydrothorax, site of EGFR mutations and EGFR-TKIs treatment were adjusted using propensity score-matching (PSM). The Kaplan-Meier survival curves and log-rank test were used to analyze progression-free survival (PFS) and overall survival (OS). The co-mutation characteristics of BLDM-LUAD patients harboring EGFR mutations were analyzed by NGS panels. 64 patients with advanced lung adenocarcinoma harboring EGFR mutations and first-line treatment of EGFR-TKIs were successfully matched. BLDM-LUAD (n = 32) have significantly longer median PFS than control group (n = 32) (mPFS: 14 vs 6.2 months; p = .002) and insignificantly longer median OS than control group (mOS: 45 vs 25 months; p = .052). The patients with BLDM-LUAD have the higher frequency of EGFR mutation than control group (84.1% vs 62.0%) before PSM. The co-mutation genes kirsten rat sarcoma viral oncogene homolog (KRAS) (9.4%), ataxia telangiectasia-mutated (ATM) (7.4%) and mesenchymal-epithelial transition (MET) (3.1%) only appeared in the control group after PSM. The BLDM-LUAD harboring EGFR mutations was associated with a favorable prognosis to EGFR-TKI.