Search Results (57)

Exosomes, extracellular vesicles known for their stability, low immunogenicity, and excellent tissue penetration, are employed as delivery vehicles. These exosomes can traverse the tumor barrier and deliver therapeutic agents directly into pancreatic cancer cells. Targeted exosome vectors containing gene fragments to inhibit Kirsten rat sarcoma viral oncogene homolog (KRAS) activity are crucial for treating pancreatic tumors. Therefore, the content of the exosomes is critical. This study aims to compare the function of exosomes released by HEK-293T cells when exposed to ultraviolet A/B and ultraviolet C irradiation to determine its impact. HEK-293T cells were irradiated with ultraviolet A/B, and ultraviolet C for various indicated times, after which the cell count and exosome secretion were measured. Exosomes derived from HEK-293T cells were isolated through differential centrifugation and identified using four methods: cell counting, Bradford assay, nanoparticle tracking analysis (NTA), and Western blot analysis. Preliminary studies demonstrated that the cell count and Bradford assay expression were reduced in ultraviolet C compared to the control, with similar levels observed for ultraviolet A/B and the control. Exosome expression in Western blot analysis showed ultraviolet C, but a higher amount of ultraviolet A/B compared to the control. We introduce a comprehensive approach to ultraviolet irradiation, including ultraviolet A/B and ultraviolet C, which enhanced the secretion of exosomes by HEK-293T targeted vectors for KRAS inhibition in pancreatic cancer. Full article

We used molecular docking to determine the binding energy and interactions of apigenin and 16 related flavonoids, with 24 distinct proteins having diverse biological functions. We aimed to identify potential inhibitors of these proteins and understand the structural configurations of flavonoids impacting their binding energy. Our results demonstrate that apigenin exhibits high binding energies (a surrogate for binding affinity or inhibitory potential) to all tested proteins. The strongest binding energy was −8.21 kcal/mol for p38 mitogen-activated protein kinases, while the weakest was −5.34 kcal/mol for cyclin-dependent kinase 4. Apigenin and many other flavonoids showed high binding energies on xanthine oxidase (1.1–1.5 fold of febuxostat) and DNA methyltransferases (1.1–1.2 fold of azacytidine). We uncovered high binding energies of apigenin and certain flavonoids with mutated Kirsten rat sarcoma viral oncogene homolog at G12D (KRAS G12D), G12V, and G12C. Consequently, apigenin and certain flavonoids have the potential to effectively inhibit pan-KRAS oncogenic activity, not just on specific KRAS mutations. Apigenin and certain flavonoids also have high binding energies with aromatase (involved in estrogen production) and bacterial infections, i.e., DNA gyrase B and 3R-hydroxy acyl-ACP dehydratase (FABZ). Our findings are pivotal in identifying specific flavonoids that can effectively inhibit targeted proteins, paving the way for the development of innovative flavonoid-based drugs. Full article

Objective: Rat sarcoma (Ras) proteins, Kirsten, Harvey, and Neuroblastoma rat sarcoma viral oncogene homolog (KRAS, HRAS, and NRAS, respectively), are a family of GTPases, which are key regulators of cellular growth, differentiation, and apoptosis through signal transduction pathways modulated by growth factors that have been recognized to be dysregulated in PCOS. This study explores Ras signaling proteins and growth factor-related proteins in polycystic ovary syndrome (PCOS). Methods: In a well-validated PCOS database of 147 PCOS and 97 control women, plasma was batch analyzed using Somascan proteomic analysis for circulating KRas, Ras GTPase-activating protein-1 (RASA1), and 45 growth factor-related proteins. The cohort was subsequently stratified for BMI (body mass index), testosterone, and insulin resistance (HOMA-IR) for subset analysis. Results: Circulating KRas, and RASA1 did not differ between PCOS and control women (p > 0.05). EGF1, EGFR, and EGFRvIII were decreased in PCOS (p = 0.04, p = 0.04 and p < 0.001, respectively). FGF8, FGF9, and FGF17 were increased in PCOS (p = 0.02, p = 0.03 and p = 0.04, respectively), and FGFR1 was decreased in PCOS (p < 0.001). VEGF-D (p < 0.001), IGF1 (p < 0.001), IGF-1sR (p = 0.02), and PDGFRA (p < 0.001) were decreased in PCOS compared to controls. After stratifying for BMI ≤ 29.9 kg/m², EGFR FGF8, FGFR1 VEGF-D, IGF1, and IGF-1sR differed (p < 0.05) though EGF1, EGFRvIII, FGF8, FGFR1, and VEGF-D no longer differed; after subsequently stratifying for HOMA-IR, only FGFR1, VEGF-D, IGF1, and IGF-1sR differed between groups (p < 0.05). Conclusions: Several growth factors that activate Ras differ between women with and without PCOS, and when stratified for BMI and HOMA-IR, only FGFR1, VEGF-D, IGF1, and IGF-1sR differed; these appear to be inherent features of the pathophysiology of PCOS. Full article

Our study’s aim was to evaluate the clinicopathological profile of colorectal cancer (CRC) patients from North-East Romania in relation to the Kirsten rat sarcoma viral oncogene homolog (KRAS). We designed a retrospective study on 108 CRC patients using the fully automated real-time PCR-based molecular testing system, Idylla^TMKRAS Mutation Test (Biocartis, Mechelen, Belgium). Of the patients, 64 (59.3%) were men and 62 (57.4%) were older than the group average, with left bowel location in 38 cases (35.2%), adenocarcinoma NOS in 102 cases (94.4%), mixed histological pattern in 65 cases (60.2%), T3 in 60 patients (55.6%), N2 in 46 patients (42.6%), and 7–12 tumour buds registered in 58 tumours (53.7%). A total of 54 tumour samples (50%) showed KRAS mutation. Statistical comparative analyses associated KRAS mutations with the histopathological pattern (p = 0.018), tumour grade (p = 0.030), depth of invasion (pT) (p < 0.001), lymph node involvement (pN) (p < 0.001), venous vascular invasion (p = 0.048), and tumour buds’ number (p = 0.007). Our results demonstrate the relationship between KRAS mutation and clinicopathological features, with possible impact in clinical tumour stratification and therapeutic management. Full article

Kirsten Rat Sarcoma viral oncogene homolog (KRAS) is a frequently occurring mutation in non-small-cell lung cancer (NSCLC) and influences cancer treatment and disease progression. In this study, a machine learning (ML) pipeline was applied to radiomic features extracted from public and internal CT images to identify KRAS mutations in NSCLC patients. Both datasets were analyzed using parametric (t test) and non-parametric statistical tests (Mann–Whitney U test) and dimensionality reduction techniques. Afterwards, the proposed ML pipeline was applied to both datasets using a five-fold cross-validation on the training set (70/30 train/test split) before being validated on the other dataset. The results show that the radiomic features are significantly different (Mann–Whitney U test; p < 0.05) between the two datasets, despite the use of identical feature extraction methods. Model transferability is therefore difficult to achieve, which became evident during external testing (F1 score = 0.41). Oversampling, undersampling, clustering and harmonization techniques were applied to balance and harmonize the datasets, but did not improve the classification of KRAS mutation presence. In general, due to only a single moderate result (highest test F1 score = 0.67), the accuracy of KRAS prediction is not sufficient for clinical application. In future work, the complexity of KRAS mutation might be addressed by taking submutations into consideration. Larger multicentric datasets with balanced tumor stages, including multi-scanner datasets, seem to be necessary for building robust predictive models. Full article

Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) gene variations are linked to the development of numerous cancers, including non-small cell lung cancer (NSCLC), colorectal cancer (CRC), and pancreatic ductal adenocarcinoma (PDAC). The lack of typical drug-binding sites has long hampered the discovery of therapeutic drugs targeting KRAS. Since “CodeBreaK 100” demonstrated Sotorasib’s early safety and efficacy and led to its approval, especially in the treatment of non-small cell lung cancer (NSCLC), the subsequent identification of specific inhibitors for the p.G12C mutation has offered hope. However, the CodeBreaK 200 study found no significant difference in overall survival (OS) between patients treated with Docetaxel and Sotorasib (AMG 510), adding another degree of complexity to this ongoing challenge. The current study compares the three-dimensional structures of the two major KRAS isoforms, KRAS4A and KRAS4B. It also investigates the probable structural changes caused by the three major mutations (p.G12C, p.G12D, and p.G12V) within Sotorasib’s pocket domain. The computational analysis demonstrates that the wild-type and mutant isoforms have distinct aggregation propensities, resulting in the creation of alternate oligomeric configurations. This study highlights the increased complexity of the biological issue of using KRAS as a therapeutic target. The present study stresses the need for a better understanding of the structural dynamics of KRAS and its mutations to design more effective therapeutic approaches. It also emphasizes the potential of computational approaches to shed light on the complicated molecular pathways that drive KRAS-mediated oncogenesis. This study adds to the ongoing efforts to address the therapeutic hurdles presented by KRAS in cancer treatment. Full article

This critical review investigates the impact of SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 4 (SMARCA4) mutations on survival outcomes in non-small cell lung cancer (NSCLC) through an analysis of 21 peer-reviewed articles. Survival analyses across this review demonstrated consistently worse outcomes for SMARCA4-mutated vs. SMARCA4 wild-type NSCLC patients, specifically emphasizing class 1 truncating mutations as an independent factor for poor overall survival. In addition, this review explores the clinicopathologic characteristics of SMARCA4 mutations and their impact on various treatment modalities, including immune checkpoint inhibitors (ICIs) both with and without Kirsten rat sarcoma viral oncogene homolog (KRAS) co-mutations. The potential ineffectiveness of ICI treatment in NSCLC is explored through the impact of SMARCA4/KRAS co-mutations on the tumor microenvironment. Moreover, this NSCLC review consistently reported statistically worse overall survival outcomes for SMARCA4/KRAS co-mutations than SMARCA4 wild-type/KRAS-mutated cohorts, extending across ICIs, chemo-immunotherapy (CIT), and KRAS G12C inhibitors. Designing prospective clinical SMARCA4-mutated or SMARCA4/KRAS co-mutated NSCLC trials to evaluate targeted therapies and immunotherapy may lead to a better understanding of how to improve cancer patients’ outcomes and survival rates. Full article

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. Full article

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. Full article

The Kirsten rat sarcoma viral oncogene homolog (KRAS)^G12C mutation is prevalent in lung adenocarcinoma (LUAD), driving tumor progression and indicating a poor prognosis. While the FDA-approved AMG510 (Sotorasib) initially demonstrated efficacy in treating KRAS^G12C-mutated LUAD, resistance emerged within months. Data from AMG510 treatment-resistant LUAD (GSE204753) and single-cell datasets (GSE149655) were analyzed. Gene set variation analysis (GSVA) and gene set enrichment analysis (GSEA) were used to explore enriched signaling pathways, nomogram models were constructed, and transcription factors predicting resistance biomarkers were predicted. CIBERSORT identified immune cell subpopulations, and their association with resistance biomarkers was assessed through single-cell analysis. AMG510-resistant LUAD cells (H358-AR) were constructed, and proliferative changes were evaluated using a CCK-8 assay. Key molecules for AMG510 resistance, including SLC2A1, TLE1, FAM83A, HMGA2, FBXO44, and MTRNR2L12, were recognized. These molecules impacted multiple signaling pathways and the tumor microenvironment and were co-regulated by various transcription factors. Single-cell analysis revealed a dampening effect on immune cell function, with associations with programmed cell death ligand 1 (PDL1) expression, cytokine factors, and failure factors. The findings indicate that these newly identified biomarkers are linked to the abnormal expression of PDL1 and have the potential to induce resistance through immunosuppression. These results highlight the need for further research and therapeutic intervention to address this issue effectively. Full article

The aberrant activation of signaling pathways contributes to cancer cells with metabolic reprogramming. Thus, targeting signaling modulators is considered a potential therapeutic strategy for cancer. Subcellular fractionation, coimmunoprecipitation, biochemical analysis, and gene manipulation experiments revealed that decreasing the interaction of kirsten rat sarcoma viral oncogene homolog (KRAS) with p110α in lipid rafts with the use of naringenin (NGN), a citrus flavonoid, causes lipid raft-associated phosphatidylinositol 3-kinase (PI3K)−GTP-ras-related C3 botulinum toxin substrate 1 (Rac1)−protein kinase B (Akt)-regulated metabolic dysfunction of glycolysis and mitochondrial oxidative phosphorylation (OXPHOS), leading to apoptosis in human nasopharyngeal carcinoma (NPC) cells. The use of lethal-7g (let-7g) mimic and let-7g inhibitor confirmed that elevated let-7g resulted in a decrease in KRAS expression, which attenuated the PI3K−Rac1−Akt−BCL-2/BCL-x_L-modulated mitochondrial energy metabolic functions. Increased let-7g depends on the suppression of the RNA-specificity of monocyte chemoattractant protein-induced protein-1 (MCPIP1) ribonuclease since NGN specifically blocks the degradation of pre-let-7g by NPC cell-derived immunoprecipitated MCPIP1. Converging lines of evidence indicate that the inhibition of MCPIP1 by NGN leads to let-7g upregulation, suppressing oncogenic KRAS-modulated PI3K–Rac1–Akt signaling and thereby impeding the metabolic activities of aerobic glycolysis and mitochondrial OXPHOS. Full article

Autophagy is a tightly regulated catabolic process involved in the degradation and recycling of proteins and organelles. Ubiquitination plays an important role in the regulation of autophagy. Vacuole Membrane Protein 1 (VMP1) is an essential autophagy protein. The expression of VMP1 in pancreatic cancer stem cells carrying the activated Kirsten rat sarcoma viral oncogene homolog (KRAS) triggers autophagy and enables therapy resistance. Using biochemical and cellular approaches, we identified ubiquitination as a post-translational modification of VMP1 from the initial steps in autophagosome biogenesis. VMP1 remains ubiquitinated as part of the autophagosome membrane throughout autophagic flux until autolysosome formation. However, VMP1 is not degraded by autophagy, nor by the ubiquitin–proteasomal system. Mass spectrometry and immunoprecipitation showed that the cell division cycle protein cdt2 (Cdt2), the substrate recognition subunit of the E3 ligase complex associated with cancer, cullin–RING ubiquitin ligase complex 4 (CRL4), is a novel interactor of VMP1 and is involved in VMP1 ubiquitination. VMP1 ubiquitination decreases under the CRL inhibitor MLN4924 and increases with Cdt2 overexpression. Moreover, VMP1 recruitment and autophagosome formation is significantly affected by CRL inhibition. Our results indicate that ubiquitination is a novel post-translational modification of VMP1 during autophagy in human tumor cells. VMP1 ubiquitination may be of clinical relevance in tumor-cell-therapy resistance. Full article

Data on genetic and immunophenotypical characteristics of uterine mesonephric-like adenocarcinoma (MLA) remain limited. Therefore, we aimed to investigate the clinicopathological, immunohistochemical, and molecular features of uterine MLA. We performed targeted sequencing, array comparative genomic hybridization, and immunostaining in 17, 13, and 17 uterine MLA cases, respectively. Nine patients developed lung metastases. Eleven patients experienced disease recurrences. The most frequently mutated gene was Kirsten rat sarcoma viral oncogene homolog (KRAS; 13/17). Both the primary and matched metastatic tumors harbored identical KRAS (3/4) and phosphatase and tensin homolog deleted on chromosome 10 (1/4) mutations, and did not harbor any additional mutations. A total of 2 of the 17 cases harbored tumor protein 53 (TP53) frameshift insertion and deletion, respectively. Chromosomal gains were detected in 1q (13/13), 10 (13/13), 20 (10/13), 2 (9/13), and 12 (6/13). Programmed cell death-ligand 1 overexpression or mismatch repair deficiency was not observed in any of the cases. Initial serosal extension and lung metastasis independently predicted recurrence-free survival with hazard ratios of 6.30 and 7.31, respectively. Our observations consolidated the clinicopathological and molecular characteristics of uterine MLA. Both clinicians and pathologists should consider these features to make an accurate diagnosis of uterine MLA and to ensure appropriate therapeutic management of this rare entity. Full article

Intraductal papillary mucinous neoplasm (IPMN) is the most common pancreatic cyst and a precursor of pancreatic cancer (PDAC). Since PDAC has a devastatingly high mortality rate, the early diagnosis and treatment of any precursor lesion are rational. The safety of the existing guidelines on the clinical management of IPMN has been criticized due to unsatisfactory sensitivity and specificity, showing the need for further markers. Blood obtained from patients with IPMN was therefore subjected to size-based isolation of circulating epithelial cells (CECs). We isolated CECs and evaluated their cytological characteristics. Additionally, we compared Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations in CECs and the primary IPMN tissue, since KRAS mutations are very typical for PDAC. Samples from 27 IPMN patients were analyzed. In 10 (37%) patients, CECs were isolated and showed a hybrid pattern of surface markers involving both epithelial and mesenchymal markers, suggesting a possible EMT process of the cells. Especially, patients with high-grade dysplasia in the main specimen were all CEC-positive. KRAS mutations were also present in CECs but less common than in IPMN tissue. The existence of CEC in IPMN patients offers additional blood-based research possibilities for IMPN biology. Full article

The Kirsten rat sarcoma viral oncogene homolog (KRAS) and serine/threonine kinase 11 (STK11) co-mutations are associated with the diverse phenotypic and heterogeneous oncogenic subtypes in non-small cell lung cancer (NSCLC). Due to extensive mixed evidence, there needs to be a review of the recent KRAS and STK11 mutation literature to better understand the potential clinical applications of these genomic biomarkers in the current treatment landscape. This critical review highlights the clinical studies that have elucidated the potential prognostic and predictive implications of KRAS mutations, STK11 mutations, or KRAS/STK11 co-mutations when treating metastatic NSCLC across various types of treatments (e.g., immune checkpoint inhibitors [ICIs]). Overall, KRAS mutations are associated with poor prognoses and have been determined to be a valid but weak prognostic biomarker among patients diagnosed with NSCLC. KRAS mutations in NSCLC have shown mixed results as a predictive clinical biomarker for immune checkpoint inhibitor treatment. Overall, the studies in this review demonstrate that STK11 mutations are prognostic and show mixed results as predictive biomarkers for ICI therapy. However, KRAS/STK11 co-mutations may predict primary resistance to ICI. Prospective KRAS/STK11-biomarker-driven randomized trials are needed to assess the predictive effect of various treatments on the outcomes for patients with metastatic NSCLC, as the majority of the published KRAS analyses are retrospective and hypothesis-generating in nature. Full article