New Horizons in KRAS-Mutant Lung Cancer: Dawn After Darkness

Combining RAS(ON) G12C-selective inhibitor with SHP2 inhibition sensitises lung tumours to immune checkpoint blockade

Mutant selective drugs targeting the inactive, GDP-bound form of KRASG12C have been approved for use in lung cancer, but resistance develops rapidly. Here we use an inhibitor, (RMC-4998) that targets RASG12C in its active, GTP-bound form, to treat KRAS mutant lung cancer in various immune competent mouse models. RAS pathway reactivation after RMC-4998 treatment could be delayed using combined treatment with a SHP2 inhibitor, which not only impacts tumour cell RAS signalling but also remodels the tumour microenvironment to be less immunosuppressive. In an immune inflamed model, RAS and SHP2 inhibitors in combination drive durable responses by suppressing tumour relapse and inducing development of immune memory. In an immune excluded model, combined RAS and SHP2 inhibition sensitises tumours to immune checkpoint blockade, leading to efficient tumour immune rejection. These preclinical results demonstrate the potential of the combination of RAS(ON) G12C-selective inhibitors with SHP2 inhibitors to sensitize tumours to immune checkpoint blockade.

Identification of non-actionable mutations with prognostic and predictive value in patients with advanced or metastatic non-small cell lung cancer

INTRODUCTION

Lung cancer is one of the most prevalent cancers and the leading cause of cancer death. Advanced non-small cell lung cancer (aNSCLC) patients frequently harbor mutations that impact their survival outcomes. There are limited data regarding the prognostic and predictive significance of these mutations on survival outcomes in the real-world setting.

METHODS

This observational retrospective study analyzed de-identified electronic medical records from the Flatiron Health Clinico-Genomic and FoundationCore® databases to identify patients with aNSCLC who initiated first-line immune checkpoint inhibitors (ICI; alone or in combination) or chemotherapy under routine care between 2016 and 2021. The primary objectives were to assess the prevalence of non-actionable mutations and to determine their association with overall survival (OS). Real-world progression-free survival (rwPFS) and real-world response (rwR) were investigated as secondary exploratory outcomes.

RESULTS

Based on an assessment of 185 non-actionable mutations in 2999 patients, the most prevalent mutations were TP53 (70%), KRAS (42%), CDKN2A/B (31%), and STK11 (21%). STK11, KEAP1, and CDKN2A/B mutations were significantly associated with lower rwR, shorter rwPFS and OS. KRAS mutations were clinically associated with shorter rwPFS in CIT-treated patients. Subgroup analysis revealed that fast progressors were significantly more likely to harbor STK11, KEAP1, and CDKN2A/B mutations. Accordingly, long-term survivors (LTS) showed a significantly lower prevalence of these mutations.

CONCLUSION

Our results provide evidence on the prognostic value of STK11, KEAP1, and CDKN2A/B mutations in patients with aNSCLC. Further research is required to better understand the implications of these findings on patient management and future trial design and treatment selection.

Synergy of EGFR and AURKA Inhibitors in KRAS-mutated Non-small Cell Lung Cancers

The most common oncogenic driver mutations for non-small cell lung cancer (NSCLC) activate EGFR or KRAS. Clinical trials exploring treatments for EGFR- or KRAS-mutated (EGFRmut or KRASmut) cancers have focused on small-molecule inhibitors targeting the driver mutations. Typically, these inhibitors perform more effectively based on combination with either chemotherapies, or other targeted therapies. For EGFRmut NSCLC, a combination of inhibitors of EGFR and Aurora-A kinase (AURKA), an oncogene commonly overexpressed in solid tumors, has shown promising activity in clinical trials. Interestingly, a number of recent studies have indicated that EGFR activity supports overall viability of tumors lacking EGFR mutations, and AURKA expression is abundant in KRASmut cell lines. In this study, we have evaluated dual inhibition of EGFR and AURKA in KRASmut NSCLC models. These data demonstrate synergy between the EGFR inhibitor erlotinib and the AURKA inhibitor alisertib in reducing cell viability and clonogenic capacity in vitro, associated with reduced activity of EGFR pathway effectors, accumulation of enhanced aneuploid cell populations, and elevated cell death. Importantly, the erlotinib-alisertib combination also synergistically reduces xenograft growth in vivo. Analysis of signaling pathways demonstrated that the combination of erlotinib and alisertib was more effective than single-agent treatments at reducing activity of EGFR and pathway effectors following either brief or extended administration of the drugs. In sum, this study indicates value of inhibiting EGFR in KRASmut NSCLC, and suggests the specific value of dual inhibition of AURKA and EGFR in these tumors.

SIGNIFICANCE

The introduction of specific KRAS G12C inhibitors to the clinical practice in lung cancer has opened up opportunities that did not exist before. However, G12C alterations are only a subtype of all KRAS mutations observed. Given the high expression of AURKA in KRASmut NSCLC, our study could point to a potential therapeutic option for this subgroup of patients.

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.

Phosphorylation of AGO2 by TBK1 Promotes the Formation of Oncogenic miRISC in NSCLC

Non-small-cell lung cancer (NSCLC) is a highly lethal tumor that often develops resistance to targeted therapy. It is shown that Tank-binding kinase 1 (TBK1) phosphorylates AGO2 at S417 (pS417-AGO2), which promotes NSCLC progression by increasing the formation of microRNA-induced silencing complex (miRISC). High levels of pS417-AGO2 in clinical NSCLC specimens are positively associated with poor prognosis. Interestingly, the treatment with EGFR inhibitor Gefitinib can significantly induce pS417-AGO2, thereby increasing the formation and activity of oncogenic miRISC, which may contribute to NSCLC resistance to Gefitinib. Based on these, two therapeutic strategies is developed. One is jointly to antagonize multiple oncogenic miRNAs highly expressed in NSCLC and use TBK1 inhibitor Amlexanox reducing the formation of oncogenic miRISC. Another approach is to combine Gefitinib with Amlexanox to inhibit the progression of Gefitinib-resistant NSCLC. This findings reveal a novel mechanism of oncogenic miRISC regulation by TBK1-mediated pS417-AGO2 and suggest potential therapeutic approaches for NSCLC.

Impact of KRASG12D subtype and concurrent pathogenic mutations on advanced non-small cell lung cancer outcomes

PURPOSE

Mutations in the Kirsten rat sarcoma viral (KRAS) oncogene constitute a significant driver of lung adenocarcinoma, present in 10-40% of patients, which exhibit heterogeneous clinical outcomes, mainly driven by concurrent genetic alterations. However, characterization of KRAS mutational subtypes and their impact on clinical outcomes in Latin America is limited.

METHODS

A cohort study was conducted at the National Cancer Institute (INCan) of Mexico. Individuals with advance-staged of adenocarcinoma and KRAS mutations, detected by next-generation sequencing, having undergone at least one line of therapy were included for analysis. Clinical and pathological characteristics were retrieved from institutional database from June 2014 to March 2023.

RESULTS

KRAS was identified in fifty-four (15.6%) of 346 patients, among which 50 cases were included for analysis. KRASG12D (n = 16, 32%) and KRASG12C (n = 16, 32%) represented the most prevalent subtypes. KRASG12D mutations were associated with female (p = 0.018), never smokers (p = 0.108), and concurrences with EGFR (25.0% vs. 17.6%, p = 0.124) and CDKN2A (18.8% vs. 14.7%, p = 0.157). KRASG12D patients showed a better ORR (66.6% vs. 30.0%; OR 4.66, 95% CI 1.23-17.60, p = 0.023) and on multivariate analysis was significantly associated with better PFS (HR 0.36, 95% CI 0.16-0.80; p = 0.012) and OS (HR 0.24, 95% CI 0.08-0.70; p = 0.009).

CONCLUSIONS

To our knowledge, this study represents the first effort to comprehensively characterize the molecular heterogeneity of KRAS-mutant NSCLC in Latin American patients. Our data reinforce the current view that KRAS-mutated NSCLC is not a single oncogene-driven disease and emphasizes the prognostic impact of diverse molecular profiles in this genomically defined subset of NSCLC. Further validation is warranted in larger multicenter Latin American cohorts to confirm our findings.

Multiple medicinal chemistry strategies of targeting KRAS: State-of-the art and future directions

KRAS is the most frequently mutated oncogene and drives the development and progression of malignancies, most notably non-small cell lung cancer (NSCLS), pancreatic ductal adenocarcinoma (PDAC) and colorectal cancer (CRC). However, KRAS proteins have maintained the reputation of being "undruggable" due to the lack of suitable deep pockets on its surface. One major milestone for KRAS inhibition was the discovery of the covalent inhibitors bond to the allosteric switch-II pocket of the KRASG12C protein. To date, the FDA has approved two KRASG12C inhibitors, sotorasib and adagrasib, for the treatment of patients with KRASG12C-driven cancers. Researchers have paid close attention to the development of inhibitors for other KRAS mutations and upstream regulatory factors. The KRAS targeted drug discovery has entered a state of rapid development. This article has aimed to present the current state of the art of drug development in the KRAS field. We systematically summarize recent advances in the discovery and optimization processes of direct KRAS inhibitors (including KRASG12C, KRASG12D, KRASG12A and KRASG12R inhibitors), indirect KRAS inhibitors (SOS1 and SHP2 inhibitors), pan-KRAS inhibitors, as well as proteolysis-targetingchimeras degrades and molecular chaperone modulators from the perspective of medicinal chemistry. We also discuss the current challenges and opportunities of KRAS inhibition and hope to shed light on future KRAS drug discovery.

CRISPRing KRAS: A Winding Road with a Bright Future in Basic and Translational Cancer Research

Once considered "undruggable" due to the strong affinity of RAS proteins for GTP and the structural lack of a hydrophobic "pocket" for drug binding, the development of proprietary therapies for KRAS-mutant tumors has long been a challenging area of research. CRISPR technology, the most successful gene-editing tool to date, is increasingly being utilized in cancer research. Here, we provide a comprehensive review of the application of the CRISPR system in basic and translational research in KRAS-mutant cancer, summarizing recent advances in the mechanistic understanding of KRAS biology and the underlying principles of drug resistance, anti-tumor immunity, epigenetic regulatory networks, and synthetic lethality co-opted by mutant KRAS.

Whole‑exome sequencing reveals Lewis lung carcinoma is a hypermutated Kras/Nras-mutant cancer with extensive regional mutation clusters in its genome

Lewis lung carcinoma (LLC), as a widely used preclinical cancer model, has still not been genetically and genomically characterized. Here, we performed a whole-exome sequencing analysis on the LLC cell line to elucidate its molecular characteristics and etiologies. Our data showed that LLC originated from a male mouse belonging to C57BL/6L (a transitional strain between C57BL/6J and C57BL/6N) and contains substantial somatic SNV and InDel mutations (> 20,000). Extensive regional mutation clusters are present in its genome, which were caused mainly by the mutational processes underlying the SBS1, SBS5, SBS15, SBS17a, and SBS21 signatures during frequent structural rearrangements. Thirty three deleterious mutations are present in 30 cancer genes including Kras, Nras, Trp53, Dcc, and Cacna1d. Cdkn2a and Cdkn2b are biallelically deleted from the genome. Five pathways (RTK/RAS, p53, cell cycle, TGFB, and Hippo) are oncogenically deregulated or affected. The major mutational processes in LLC include chromosomal instability, exposure to metabolic mutagens, spontaneous 5-methylcytosine deamination, defective DNA mismatch repair, and reactive oxygen species. Our data also suggest that LLC is a lung cancer similar to human lung adenocarcinoma. This study lays a molecular basis for the more targeted application of LLC in preclinical research.

A multiomic investigation of lung adenocarcinoma molecular subtypes

BACKGROUND

Lung adenocarcinoma-an aggressive and life-threatening malignancy-is a type of non-small-cell lung cancer. Despite medical advancements, the prognosis of lung adenocarcinoma remains unfavorable, likely because of its heterogeneous nature. Furthermore, few subtype-specific treatments are available for lung adenocarcinoma. This study was conducted to explore the molecular subtypes of lung adenocarcinoma.

METHODS

We performed a joint analysis of transcriptome and proteome data from East Asian patients with lung adenocarcinoma (nonsmokers, 86.5%).

RESULTS

Four novel subtypes were identified based on distinct molecular characteristics: subtypes I, II, III, and IV. In patients with subtype I lung adenocarcinoma, eukaryotic translation initiation factor 4 gamma 1 activates cell proliferation; inhibiting this factor suppresses tumor growth, and reducing its level induces autophagy. Subtype II is characterized by Kristen rat sarcoma viral oncogene homolog-activating oncogenesis; the onset age of this subtype is the lowest among all subtypes. Subtype III manifests as an advanced disease at diagnosis; it is characterized by a core serum response-related oncogenic signature, which indicates poor overall survival in Western patients with lung cancer. Subtype IV is more common in men than in women; it has astroglial characteristics. A Connectivity Map analysis revealed that the oncogenic expression patterns corresponding to subtypes I, II, III, and IV can be reversed by the inhibitors of Inhibitor of κB (IκB) kinase (eg, withaferin A), mammalian target of rapamycin (eg, everolimus), Src proto-oncogene (Src) (eg, saracatinib), and Transforming Growth Factor (TGF)-β/Smad (eg, LY-364947), respectively.

CONCLUSION

This study introduced an innovative multiomics data analysis pipeline. Using this approach, we successfully identified four molecular subtypes of lung adenocarcinoma and their candidate therapeutic agents. The newly identified subtypes can be combined with the current biomarkers to generate a comprehensive roadmap for treatment decision-making.

Recent advances in molecular targeted therapy of lung cancer: Possible application in translation medicine

Lung cancer is one of the leading causes of death among all cancer deaths. This cancer is classified into two different histological subtypes: non-small cell lung cancer (NSCLC), which is the most common subtype, and small cell lung cancer (SCLC), which is the most aggressive subtype. Understanding the molecular characteristics of lung cancer has expanded our knowledge of the cellular origins and molecular pathways affected by each of these subtypes and has contributed to the development of new therapies. Traditional treatments for lung cancer include surgery, chemotherapy, and radiotherapy. Advances in understanding the nature and specificity of lung cancer have led to the development of immunotherapy, which is the newest and most specialized treatment in the treatment of lung cancer. Each of these treatments has advantages and disadvantages and causes side effects. Today, combination therapy for lung cancer reduces side effects and increases the speed of recovery. Despite the significant progress that has been made in the treatment of lung cancer in the last decade, further research into new drugs and combination therapies is needed to extend the clinical benefits and improve outcomes in lung cancer. In this review article, we discussed common lung cancer treatments and their combinations from the most advanced to the newest.

An optimized protocol for the generation and monitoring of conditional orthotopic lung cancer in the KP mouse model using an adeno-associated virus vector compatible with biosafety level 1

BACKGROUND

The inducible Kras/p53 lung adenocarcinoma mouse model, which faithfully recapitulates human disease, is routinely initiated by the intratracheal instillation of a virus-based Cre recombinase delivery system. Handling virus-based delivery systems requires elevated biosafety levels, e.g., biosafety level 2 (BSL-2). However, in experimental animal research facilities, following exposure to viral vectors in a BSL-2 environment, rodents may not be reclassified to BSL-1 according to standard practice, preventing access to small animal micro-computed tomography (micro-CT) scanners that are typically housed in general access areas such as BSL-1 rooms. Therefore, our goal was to adapt the protocol so that the Cre-induced KP mouse model could be handled under BSL-1 conditions during the entire procedure.

RESULTS

The Kras-Lox-STOP-Lox-G12D/p53 flox/flox (KP)-based lung adenocarcinoma mouse model was activated by intratracheal instillation of either an adenoviral-based or a gutless, adeno-associated viral-based Cre delivery system. Tumor growth was monitored over time by micro-CT. We have successfully substituted the virus-based Cre delivery system with a commercially available, gutless, adeno-associated, Cre-expressing vector that allows the KP mouse model to be handled and imaged in a BSL-1 facility. By optimizing the anesthesia protocol and switching to a microscope-guided vector instillation procedure, productivity was increased and procedure-related complications were significantly reduced. In addition, repeated micro-CT analysis of individual animals allowed us to monitor tumor growth longitudinally, dramatically reducing the number of animals required per experiment. Finally, we documented the evolution of tumor volume for different doses, which revealed that individual tumor nodules induced by low-titer AAV-Cre transductions can be monitored over time by micro-CT.

CONCLUSION

Modifications to the anesthesia and instillation protocols increased the productivity of the original KP protocol. In addition, the switch to a gutless, adeno-associated, Cre-expressing vector allowed longitudinal monitoring of tumor growth under BSL-1 conditions, significantly reducing the number of animals required for an experiment, in line with the 3R principles.

Identification of LGR4 as a prognostic biomarker in KRAS-mutant lung adenocarcinoma: Evidence from integrated bioinformatics analysis

Globally, lung cancer is the leading cause of cancer-related deaths, primarily non-small cell lung cancer. Kirsten Rat Sarcoma Oncogene Homolog (KRAS) mutations are common in non-small cell lung cancer and linked to a poor prognosis. Covalent inhibitors targeting KRAS-G12C mutation have improved treatment for some patients, but most KRAS-mutant lung adenocarcinoma (KRAS-MT LUAD) cases lack targeted therapies. This gap in treatment options underscores a significant challenge in the field. Our study aimed to identify hub/key genes specifically associated with KRAS-MT LUAD. These hub genes hold the potential to serve as therapeutic targets or biomarkers, providing insights into the pathogenesis and prognosis of lung cancer. We performed a comprehensive analysis on KRAS-MT LUAD samples using diverse data sources. This included TCGA project data for RNA-seq, clinical information, and somatic mutations, along with RNA-seq data for adjacent normal tissues. DESeq2 identified differentially expressed genes (DEGs), while weighted gene co-expression network analysis revealed co-expression modules. Overlapping genes between DEGs and co-expression module with the highest significance were analyzed using gene set enrichment analysis and protein-protein interaction network analysis. Hub genes were identified with the Maximal Clique Centrality algorithm in Cytoscape. Prognostic significance was assessed through survival analysis and validated using the GSE72094 dataset from Gene Expression Omnibus (GEO) database. In KRAS-MT LUAD, 3122 DEGs were found (2131 up-regulated, 985 down-regulated). The blue module, among 25 co-expression modules from weighted gene co-expression network analysis, had the strongest correlation. 804 genes overlapped between DEGs and the blue module. Among 20 hub genes in the blue module, leucine-rich repeats containing G protein-coupled receptor 4 (LGR4) overexpression correlated with worse overall survival. The prognostic significance of LGR4 was confirmed using GSE72094, but surprisingly, the direction of the association was opposite to what was expected. LGR4 stands as a promising biomarker in KRAS-MT LUAD prognosis. Contrasting associations in TCGA and GSE72094 datasets reveal the intricate nature of KRAS-MT LUAD. Additional explorations are imperative to grasp the precise involvement of LGR4 in lung adenocarcinoma prognosis, particularly concerning KRAS mutations. These insights could potentially pave the way for targeted therapeutic interventions, addressing the existing unmet demands in this specific subgroup.

Acquired resistance to KRAS G12C small-molecule inhibitors via genetic/nongenetic mechanisms in lung cancer

Inherent or acquired resistance to sotorasib poses a substantialt challenge for NSCLC treatment. Here, we demonstrate that acquired resistance to sotorasib in isogenic cells correlated with increased expression of integrin β4 (ITGB4), a component of the focal adhesion complex. Silencing ITGB4 in tolerant cells improved sotorasib sensitivity, while overexpressing ITGB4 enhanced tolerance to sotorasib by supporting AKT-mTOR bypass signaling. Chronic treatment with sotorasib induced WNT expression and activated the WNT/β-catenin signaling pathway. Thus, silencing both ITGB4 and β-catenin significantly improved sotorasib sensitivity in tolerant, acquired, and inherently resistant cells. In addition, the proteasome inhibitor carfilzomib (CFZ) exhibited synergism with sotorasib by down-regulating ITGB4 and β-catenin expression. Furthermore, adagrasib phenocopies the combination effect of sotorasib and CFZ by suppressing KRAS activity and inhibiting cell cycle progression in inherently resistant cells. Overall, our findings unveil previously unrecognized nongenetic mechanisms underlying resistance to sotorasib and propose a promising treatment strategy to overcome resistance.

Prognostic Implication of KRAS G12C Mutation in a Real-World KRAS-Mutated Stage IV NSCLC Cohort Treated With Immunotherapy in The Netherlands

Introduction

With the approval of G12C inhibitors as the second line of treatment for KRAS G12C-mutated NSCLC, and the expanding research regarding targeting KRAS, it is key to understand the prognostic implication of KRAS G12C in the current first line of treatment. We compared overall survival (OS) of patients with stage IV KRAS G12C-mutated NSCLC to those with a KRAS non-G12C mutation in a first-line setting of (chemo)immunotherapy.

Methods

This nationwide population-based study used real-world data from The Netherlands Cancer Registry. We selected patients with stage IV KRAS-mutated lung adenocarcinoma diagnosed in 2019 to 2020 who received first-line (chemo-)immunotherapy. Primary outcome was OS.

Results

From 28,120 registered patients with lung cancer, 1185 were selected with a KRAS mutation, of which 494 had a KRAS G12C mutation. Median OS was 15.5 months (95% confidence interval [CI]: 13.6-18.4) for KRAS G12C versus 14.0 months (95% CI:11.2-15.7) for KRAS non-G12C (p = 0.67). In multivariable analysis, KRAS subtype was not associated with OS (hazard ratio = 0.95, 95% CI: 0.82-1.10). For the subgroup with programmed death-ligand 1 at 0% to 49% who received chemoimmunotherapy, median OS was 13.3 months (95% CI: 10.5-15.2) for G12C and 9.8 months (95% CI: 8.6-11.3) for non-G12C (p = 0.48). For the subgroup with programmed death-ligand 1 more than or equal to 50% who received monoimmunotherapy, the median OS was 22.0 months (95% CI: 18.4-27.3) for G12C and 18.9 months (95% CI: 14.9-25.2) for non-G12C (p = 0.36).

Conclusions

There was no influence of KRAS subtype (G12C versus non-G12C) on OS in patients with KRAS-mutated stage IV NSCLC treated with first-line (chemo)immunotherapy.

Chemical remodeling of a cellular chaperone to target the active state of mutant KRAS

The discovery of small-molecule inhibitors requires suitable binding pockets on protein surfaces. Proteins that lack this feature are considered undruggable and require innovative strategies for therapeutic targeting. KRAS is the most frequently activated oncogene in cancer, and the active state of mutant KRAS is such a recalcitrant target. We designed a natural product-inspired small molecule that remodels the surface of cyclophilin A (CYPA) to create a neomorphic interface with high affinity and selectivity for the active state of KRASG12C (in which glycine-12 is mutated to cysteine). The resulting CYPA:drug:KRASG12C tricomplex inactivated oncogenic signaling and led to tumor regressions in multiple human cancer models. This inhibitory strategy can be used to target additional KRAS mutants and other undruggable cancer drivers. Tricomplex inhibitors that selectively target active KRASG12C or multiple RAS mutants are in clinical trials now (NCT05462717 and NCT05379985).

Discovery of new thieno[2,3-d]pyrimidines as EGFR tyrosine kinase inhibitors for cancer treatment

Background: EGFR has been considered a vital molecular target in cancer management. Aim: The discovery of new thieno[2,3-d]pyrimidine derivatives as EGFR tyrosine kinase inhibitors. Methods: Nine derivatives were designed, synthesized and subjected to in vitro and in silico studies. Results: Compound 7a significantly inhibited the growth of HepG2 and PC3 cells for both EGFR wild-type and EGFRT790M. Compound 7a caused a significant apoptotic effect, arresting HepG2 cells' growth in the S and G2/M phases. Docking and molecular dynamics simulation studies confirmed the correct and stable binding modes of the synthesized compounds against the active sites. Conclusion: Compound 7a is a promising dual EGFR inhibitor for cancer treatment.

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.

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.

The role of oncogenes and tumor suppressor genes in determining survival rates of lung cancer patients in the population of North Sumatra, Indonesia

Background: Gaining a better understanding of molecular alterations in the pathogenesis of lung cancer reveals a significant change in approach to the management and prognosis of lung cancer. Several oncogenes and tumor suppressor genes have been identified and have different roles related to survival rates in lung cancer patients. This study aims to determine the role of KRAS, EGFR, and TP53 mutations in the survival rate of lung cancer patients in the population of North Sumatra. Methods: This is a retrospective cohort study involving 108 subjects diagnosed with lung cancer from histopathology specimens. DNA extractions were performed using FFPE followed by PCR examinations for assessing the expressions of EGFR, RAS, and TP53 protein. Sequencing analysis was carried out to determine the mutations of EGFR exon 19 and 21, RAS protein exon 2, and TP53 exon 5-6 and 8-9. Data input and analysis were conducted using statistical analysis software for Windows. The survival rate analysis was presented with Kaplan Meier. Results: 52 subjects completed all procedures in this study. Most of the subjects are male (75%), above 60 years old (53.8%), heavy smokers (75%), and suffer from adenocarcinoma type of lung cancer (69.2%). No subjects showed KRAS exon 2 mutations. Overall survival rates increased in patients with EGFR mutations (15 months compared to 8 months; p=0.001) and decreased in patients with TP53 mutations (7 months compared to 9 months; p=0.148). Also, there was increasing Progression-Free Survival in patients with EGFR mutations (6 months compared to 3 months) ( p=0.19) and decreasing PFS in patients with TP53 mutations (3 months compared to 6 months) ( p=0.07). Conclusions: There were no KRAS mutations in this study. EGFR mutations showed a higher survival rate, while TP53 mutations showed a lower survival rate in overall survival and progression-free survival.

Overall survival in patients with advanced non-small cell lung cancer with KRAS G12C mutation with or without STK11 and/or KEAP1 mutations in a real-world setting

BACKGROUND

KRAS mutations occur frequently in advanced non-small cell lung cancer (aNSCLC); the G12C mutation is the most prevalent. Alterations in STK11 or KEAP1 commonly co-occur with KRAS mutations in aNSCLC. Using real-world data, we assessed the effect of KRAS G12C mutation with or without STK11 and/or KEAP1 mutations on overall survival (OS) in patients with aNSCLC receiving cancer immunotherapy (CIT), chemotherapy, or both in first line (1L) and second line (2L).

METHODS

Patients diagnosed with aNSCLC between January 2011 and March 2020 in a clinico-genomic database were included. Cox proportional hazards models adjusted for left truncation, baseline demographics and clinical characteristics were used to analyze the effect of STK11 and/or KEAP1 co-mutational status on OS in patients with KRAS wild-type (WT) or G12C mutation.

RESULTS

Of 2715 patients with aNSCLC without other actionable driver mutations, 1344 (49.5%) had KRAS WT cancer, and 454 (16.7%) had KRAS G12C-positive cancer. At 1L treatment start, significantly more patients with KRAS G12C-positive cancer were female, smokers, and had non-squamous histology, a higher prevalence of metastasis and programmed death-ligand 1 positivity than those with KRAS WT cancer. Median OS was comparable between patients with KRAS G12C-positive and KRAS WT cancer when receiving chemotherapy or combination CIT and chemotherapy in the 1L or 2L. Median OS was numerically longer in patients with KRAS G12C vs KRAS WT cancer treated with 1L CIT (30.2 vs 10.6 months, respectively) or 2L CIT (11.3 vs 7.6 months, respectively). Co-mutation of STK11 and KEAP1 was associated with significantly shorter OS in patients receiving any type of 1L therapy, regardless of KRAS G12C mutational status.

CONCLUSIONS

This real-world study showed that patients with KRAS G12C-positive or KRAS WT cancer have similar OS in the 1L or 2L when treated with chemotherapy or combination CIT and chemotherapy. In contrast to aNSCLC patients with EGFR or ALK driver mutations, patients with KRAS G12C-positive cancer may benefit from CIT monotherapy. Co-mutation of STK11 and KEAP1 was associated with significantly shorter survival, independent of KRAS G12C mutational status, reflecting the poor prognosis and high unmet need in this patient population.

Benchmarking integration of single-cell differential expression

Integration of single-cell RNA sequencing data between different samples has been a major challenge for analyzing cell populations. However, strategies to integrate differential expression analysis of single-cell data remain underinvestigated. Here, we benchmark 46 workflows for differential expression analysis of single-cell data with multiple batches. We show that batch effects, sequencing depth and data sparsity substantially impact their performances. Notably, we find that the use of batch-corrected data rarely improves the analysis for sparse data, whereas batch covariate modeling improves the analysis for substantial batch effects. We show that for low depth data, single-cell techniques based on zero-inflation model deteriorate the performance, whereas the analysis of uncorrected data using limmatrend, Wilcoxon test and fixed effects model performs well. We suggest several high-performance methods under different conditions based on various simulation and real data analyses. Additionally, we demonstrate that differential expression analysis for a specific cell type outperforms that of large-scale bulk sample data in prioritizing disease-related genes.

KRAS-Mutant Lung Cancer: Targeting Molecular and Immunologic Pathways, Therapeutic Advantages and Restrictions

RAS mutations are among the most common oncogenic mutations in human cancers. Among RAS mutations, KRAS has the highest frequency and is present in almost 30% of non-small-cell lung cancer (NSCLC) patients. Lung cancer is the number one cause of mortality among cancers as a consequence of outrageous aggressiveness and late diagnosis. High mortality rates have been the reason behind numerous investigations and clinical trials to discover proper therapeutic agents targeting KRAS. These approaches include the following: direct KRAS targeting; synthetic lethality partner inhibitors; targeting of KRAS membrane association and associated metabolic rewiring; autophagy inhibitors; downstream inhibitors; and immunotherapies and other immune-modalities such as modulating inflammatory signaling transcription factors (e.g., STAT3). The majority of these have unfortunately encountered limited therapeutic outcomes due to multiple restrictive mechanisms including the presence of co-mutations. In this review we plan to summarize the past and most recent therapies under investigation, along with their therapeutic success rate and potential restrictions. This will provide useful information to improve the design of novel agents for treatment of this deadly disease.

Impact of KRAS Mutations on Clinical Outcomes of Patients with Advanced Non-Squamous Non-Small Cell Lung Cancer Receiving Anti-PD-1/PD-L1 Therapy

BACKGROUND

KRAS is the most frequently mutated gene in non-small cell lung cancer (NSCLC), however conflicting data are available on its role as a biomarker.

OBJECTIVE

The aim of our work was to investigate the impact of KRAS mutations on response and survival outcomes in advanced non-squamous NSCLC patients treated with immune checkpoint inhibitors alone or in combination with chemotherapy.

PATIENTS AND METHODS

We retrospectively identified 119 patients, most of whom (58%) were KRAS wild type. For each patient we evaluated overall survival (OS), progression-free survival (PFS), and disease control rate (DCR). An exploratory analysis was performed among KRAS mutated patients to investigate the impact of specific KRAS mutations on response and survival outcomes.

RESULTS

After a median follow-up of 10.3 months, the median OS was 14.9 months (95% confidence interval [CI] 7.6-22.7) in wild-type KRAS patients versus 14.7 months (95% CI 8.0-19.5) in mutated KRAS patients (p = 0.529). No differences were detected between the two groups in terms of PFS and DCR. Patients with a KRAS G12C mutation reported survival and response outcomes that were not statistically different from those of patients with other KRAS mutations.

CONCLUSION

Our data confirmed that KRAS mutational status is not associated with survival and response outcomes in advanced non-squamous NSCLC patients treated with immunotherapy alone or combined with chemotherapy.

MEK inhibitor resistance in lung adenocarcinoma is associated with addiction to sustained ERK suppression

MEK inhibitors (MEKi) have limited efficacy in KRAS mutant lung adenocarcinoma (LUAD) patients, and this is attributed to both intrinsic and adaptive mechanisms of drug resistance. While many studies have focused on the former, there remains a dearth of data regarding acquired resistance to MEKi in LUAD. We established trametinib-resistant KRAS mutant LUAD cells through dose escalation and performed targeted MSK-IMPACT sequencing to identify drivers of MEKi resistance. Comparing resistant cells to their sensitive counterparts revealed alteration of genes associated with trametinib response. We describe a state of "drug addiction" in resistant cases where cells are dependent on continuous culture in trametinib for survival. We show that dependence on ERK2 suppression underlies this phenomenon and that trametinib removal hyperactivates ERK, resulting in ER stress and apoptosis. Amplification of KRAS^G12C occurs in drug-addicted cells and blocking mutant-specific activity with AMG 510 rescues the lethality associated with trametinib withdrawal. Furthermore, we show that increased KRAS^G12C expression is lethal to other KRAS mutant LUAD cells, consequential to ERK hyperactivation. Our study determines the drug-addicted phenotype in lung cancer is associated with KRAS amplification and demonstrates that toxic acquired genetic changes can develop de novo in the background of MAPK suppression with MEK inhibitors. We suggest that the presence of mutant KRAS amplification in patients may identify those that may benefit from a "drug holiday" to circumvent drug resistance. These findings demonstrate the toxic potential of hyperactive ERK signaling and highlight potential therapeutic opportunities in patients bearing KRAS mutations.

Non-genetic adaptive resistance to KRASG12C inhibition: EMT is not the only culprit

Adaptions to therapeutic pressures exerted on cancer cells enable malignant progression of the tumor, culminating in escape from programmed cell death and development of resistant diseases. A common form of cancer adaptation is non-genetic alterations that exploit mechanisms already present in cancer cells and do not require genetic modifications that can also lead to resistance mechanisms. Epithelial-to-mesenchymal transition (EMT) is one of the most prevalent mechanisms of adaptive drug resistance and resulting cancer treatment failure, driven by epigenetic reprogramming and EMT-specific transcription factors. A recent breakthrough in cancer treatment is the development of KRASG12C inhibitors, which herald a new era of therapy by knocking out a unique substitution of an oncogenic driver. However, these highly selective agents targeting KRASG12C, such as FDA-approved sotorasib (AMG510) and adagrasib (MRTX849), inevitably encounter multiple mechanisms of drug resistance. In addition to EMT, cancer cells can hijack or rewire the sophisticated signaling networks that physiologically control cell proliferation, growth, and differentiation to promote malignant cancer cell phenotypes, suggesting that inhibition of multiple interconnected signaling pathways may be required to block tumor progression on KRASG12C inhibitor therapy. Furthermore, the tumor microenvironment (TME) of cancer cells, such as tumor-infiltrating lymphocytes (TILs), contribute significantly to immune escape and tumor progression, suggesting a therapeutic approach that targets not only cancer cells but also the TME. Deciphering and targeting cancer adaptions promises mechanistic insights into tumor pathobiology and improved clinical management of KRASG12C-mutant cancer. This review presents recent advances in non-genetic adaptations leading to resistance to KRASG12C inhibitors, with a focus on oncogenic pathway rewiring, TME, and EMT.

A Long Overdue Targeted Treatment for KRAS Mutations in NSCLC: Spotlight on Adagrasib

KRASG12C is one of the most common oncogenes in non-small cell lung cancer (NSCLC) and is associated with a poor prognosis. Historically, KRAS mutations have been difficult to target due to lack of binding sites and exceptionally high affinity for guanosine triphosphate/guanosine diphosphate (GTP/GDP). Recently, KRASG12C selective inhibitors have shown promising results in Phase I/II studies. Here we discuss the mechanism of action, pharmacokinetic and pharmacodynamic properties, efficacy, and tolerability of adagrasib (MRTX849).

The current state of the art and future trends in RAS-targeted cancer therapies

Despite being the most frequently altered oncogenic protein in solid tumours, KRAS has historically been considered ‘undruggable’ owing to a lack of pharmacologically targetable pockets within the mutant isoforms. However, improvements in drug design have culminated in the development of inhibitors that are selective for mutant KRAS in its active or inactive state. Some of these inhibitors have proven efficacy in patients with KRAS^G12C-mutant cancers and have become practice changing. The excitement associated with these advances has been tempered by drug resistance, which limits the depth and/or duration of responses to these agents. Improvements in our understanding of RAS signalling in cancer cells and in the tumour microenvironment suggest the potential for several novel combination therapies, which are now being explored in clinical trials. Herein, we provide an overview of the RAS pathway and review the development and current status of therapeutic strategies for targeting oncogenic RAS, as well as their potential to improve outcomes in patients with RAS-mutant malignancies. We then discuss challenges presented by resistance mechanisms and strategies by which they could potentially be overcome.

The RAS oncogenes are among the most common drivers of tumour development and progression but have historically been considered undruggable. The development of direct KRAS inhibitors has changed this paradigm, although currently clinical use of these novel therapeutics is limited to a select subset of patients, and intrinsic or acquired resistance presents an inevitable challenge to cure. Herein, the authors provide an overview of the RAS pathway in cancer and review the ongoing efforts to develop effective therapeutic strategies for RAS-mutant cancers. They also discuss the current understanding of mechanisms of resistance to direct KRAS inhibitors and strategies by which they might be overcome.

Owing to intrinsic and extrinsic factors, KRAS and other RAS isoforms have until recently been impervious to targeting with small-molecule inhibitors.

Inhibitors of the KRAS^G12C variant constitute a potential breakthrough in the treatment of many cancer types, particularly non-small-cell lung cancer, for which such an agent has been approved by the FDA.

Several forms of resistance to KRAS inhibitors have been defined, including primary, adaptive and acquired resistance; these resistance mechanisms are being targeted in studies that combine KRAS inhibitors with inhibitors of horizontal or vertical signalling pathways.

Mutant KRAS has important effects on the tumour microenvironment, including the immunological milieu; these effects must be considered to fully understand resistance to KRAS inhibitors and when designing novel treatment strategies.

Molecular Biology and Therapeutic Perspectives for K-Ras Mutant Non-Small Cell Lung Cancers

In non-small cell lung cancer (NSCLC) the most common alterations are identified in the Kirsten rat sarcoma viral oncogene homolog (KRAS) gene, accounting for approximately 30% of cases in Caucasian patients. The majority of mutations are located in exon 2, with the c.34G > T (p.G12C) change being the most prevalent. The clinical relevance of KRAS mutations in NSCLC was not recognized until a few years ago. What is now emerging is a dual key role played by KRAS mutations in the management of NSCLC patients. First, recent data report that KRAS-mutant lung AC patients generally have poorer overall survival (OS). Second, a KRAS inhibitor specifically targeting the c.34G > T (p.G12C) variant, Sotorasib, has been approved by the U.S. Food and Drug Administration (FDA) and by the European Medicines Agency. Another KRAS inhibitor targeting c.34G > T (p.G12C), Adagrasib, is currently being reviewed by the FDA for accelerated approval. From the description of the biology of KRAS-mutant NSCLC, the present review will focus on the clinical aspects of KRAS mutations in NSCLC, in particular on the emerging efficacy data of Sotorasib and other KRAS inhibitors, including mechanisms of resistance. Finally, the interaction between KRAS mutations and immune checkpoint inhibitors will be discussed.

Small-Molecule RAS Inhibitors as Anticancer Agents: Discovery, Development, and Mechanistic Studies

Mutations of RAS oncogenes are responsible for about 30% of all human cancer types, including pancreatic, lung, and colorectal cancers. While KRAS1 is a pseudogene, mutation of KRAS2 (commonly known as KRAS oncogene) is directly or indirectly associated with human cancers. Among the RAS family, KRAS is the most abundant oncogene related to uncontrolled cellular proliferation to generate solid tumors in many types of cancer such as pancreatic carcinoma (over 80%), colon carcinoma (40-50%), lung carcinoma (30-50%), and other types of cancer. Once described as 'undruggable', RAS proteins have become 'druggable', at least to a certain extent, due to the continuous efforts made during the past four decades. In this account, we discuss the chemistry and biology (wherever available) of the small-molecule inhibitors (synthetic, semi-synthetic, and natural) of KRAS proteins that were published in the past decades. Commercial drugs, as well as investigational molecules from preliminary stages to clinical trials, are categorized and discussed in this study. In summary, this study presents an in-depth discussion of RAS proteins, classifies the RAS superfamily, and describes the molecular mechanism of small-molecule RAS inhibitors.

Clinical efficacy of atezolizumab plus bevacizumab and chemotherapy in KRAS-mutated non-small cell lung cancer with STK11, KEAP1, or TP53 comutations: subgroup results from the phase III IMpower150 trial

Background

The efficacy of atezolizumab (A) and/or bevacizumab (B) with carboplatin/paclitaxel (CP) chemotherapy was explored in the phase III, randomized IMpower150 study in patients with non-squamous non-small cell lung cancer (NSCLC) according to KRAS mutations (mKRAS) and co-occurring STK11, KEAP1, or TP53 mutations.

Methods

Mutation status was determined by circulating tumor DNA next-generation sequencing. Overall survival (OS) and progression-free survival (PFS) were analyzed in a mutation-evaluable intention-to-treat population (MEP; n=920) and SP263 (programmed cell death ligand 1 (PD-L1)) biomarker-evaluable population (n=774).

Results

Within the mKRAS population (24.5% of MEP), ABCP showed numerical improvements vs BCP in median OS (19.8 vs 9.9 months; HR 0.50; 95% CI 0.34 to 0.72) and PFS (8.1 vs 5.8 months; HR 0.42; 95% CI 0.29 to 0.61)—greater than with ACP (OS: 11.7 vs 9.9 months; HR 0.63; 95% CI 0.43 to 0.91; PFS: 4.8 vs 5.8 months; HR 0.80; 95% CI 0.56 to 1.13) vs BCP. Across PD-L1 subgroups in mKRAS patients, OS and PFS were longer with ABCP vs BCP, but OS with ACP was similar to BCP in PD-L1-low and PD-L1-negative subgroups. Conversely, in KRAS-WT patients, OS was longer with ACP than with ABCP or BCP across PD-L1 subgroups. KRAS was frequently comutated with STK11, KEAP1, and TP53; these subgroups conferred different prognostic outcomes. Within the mKRAS population, STK11 and/or KEAP1 mutations were associated with inferior OS and PFS across treatments compared with STK11-WT and/or KEAP1-WT. In mKRAS patients with co-occurring mSTK11 and/or mKEAP1 (44.9%) or mTP53 (49.3%), survival was longer with ABCP than with ACP or BCP.

Conclusions

These analyses support previous findings of mutation of STK11 and/or KEAP1 as poor prognostic indicators. While clinical efficacy favored ABCP and ACP vs BCP in these mutational subgroups, survival benefits were greater in the mKRAS and KEAP1-WT and STK11-WT population vs mKRAS and mKEAP1 and mSTK11 population, suggesting both prognostic and predictive effects. Overall, these results suggest that atezolizumab combined with bevacizumab and chemotherapy is an efficacious first-line treatment in metastatic NSCLC subgroups with mKRAS and co-occurring STK11 and/or KEAP1 or TP53 mutations and/or high PD-L1 expression.

Concomitant KRAS mutations attenuate sensitivity of non-small cell lung cancer cells to KRAS G12C inhibition

The development of covalent inhibitors against KRAS G12C represents a major milestone in treatment of RAS-driven cancers, especially in non-small cell lung cancer (NSCLC), where KRAS G12C is one of the most common oncogenic driver. Here we investigated if additional KRAS mutations co-occur with KRAS G12C (c.34G>T) in NSCLC tumours and if such mutation co-occurrence affects cellular response to G12C-specific inhibitors. Analysis of a large cohort of NSCLC patients whose tumours harboured KRAS mutations revealed co-occurring KRAS mutations in up to 8% of tumours with the KRAS c.34G>T mutation. KRAS c.35G>T was the most frequently co-occurring mutation, and could occur on the same allele (in cis) translating to a single mutant KRAS G12F protein, or on the other allele (in trans), translating to separate G12C and G12V mutant proteins. Introducing KRAS c.35G>T in trans in the KRAS G12C lung cancer model NCI-H358, as well as the co-occurrence in cis in the KRAS G12F lung cancer model NCI-H2291 led to cellular resistance to the G12C-specific inhibitor AZ’8037 due to continuing active MAPK and PI3K cascades in the presence of the inhibitor. Overall, our study provides a comprehensive assessment of co-occurring KRAS mutations in NSCLC and in vitro evidence of the negative impact of co-occurring KRAS mutations on cellular response to G12C inhibitors, highlighting the need for a comprehensive KRAS tumour genotyping for optimal patient selection for treatment with a KRAS G12C inhibitor.

Connecting copper and cancer: from transition metal signalling to metalloplasia

Copper is an essential nutrient whose redox properties make it both beneficial and toxic to the cell. Recent progress in studying transition metal signalling has forged new links between researchers of different disciplines that can help translate basic research in the chemistry and biology of copper into clinical therapies and diagnostics to exploit copper-dependent disease vulnerabilities. This concept is particularly relevant in cancer, as tumour growth and metastasis have a heightened requirement for this metal nutrient. Indeed, the traditional view of copper as solely an active site metabolic cofactor has been challenged by emerging evidence that copper is also a dynamic signalling metal and metalloallosteric regulator, such as for copper-dependent phosphodiesterase 3B (PDE3B) in lipolysis, mitogen-activated protein kinase kinase 1 (MEK1) and MEK2 in cell growth and proliferation and the kinases ULK1 and ULK2 in autophagy. In this Perspective, we summarize our current understanding of the connection between copper and cancer and explore how challenges in the field could be addressed by using the framework of cuproplasia, which is defined as regulated copper-dependent cell proliferation and is a representative example of a broad range of metalloplasias. Cuproplasia is linked to a diverse array of cellular processes, including mitochondrial respiration, antioxidant defence, redox signalling, kinase signalling, autophagy and protein quality control. Identifying and characterizing new modes of copper-dependent signalling offers translational opportunities that leverage disease vulnerabilities to this metal nutrient.

A Tasquinomod-loaded dopamine-modified pH sensitive hydrogel is effective at inhibiting the proliferation of KRAS mutant lung cancer cells

Hydrogels can maintain a high local drug concentration during treatments and may be useful to local targeting diseased areas. We propose a pH sensitive hydrogel consisting of poly-vinylpyrrolidone (PVP) and chitosan as a new treatment method for KRAS mutant lung cancer. Addition of dopamine improved the drug loading and release effects of this hydrogel. We demonstrate that Tasquinimod-loading of this dopamine-modified pH sensitive hydrogel is more effective than Tasquinimod alone for inhibiting the proliferation of KRAS mutant lung cancer cells. Combination of conventional drugs with hydrogels may thus provide a new treatment modality for lung cancer.

Targeting KRAS in Non-Small Cell Lung Cancer

Kirsten Rat Sarcoma viral oncogene homolog (KRAS) is the most frequently altered oncogene in Non-Small Cell Lung Cancer (NSCLC). KRAS mutant tumors constitute a heterogeneous group of diseases, different from other oncogene-derived tumors in terms of biology and response to treatment, which hinders the development of effective drugs against KRAS. Therefore, for decades, despite enormous efforts invested in the development of drugs aimed at inhibiting KRAS or its signaling pathways, KRAS was considered to be undruggable. Recently, the discovery of a new pocket under the effector binding switch II region of KRAS G12C has allowed the development of direct KRAS inhibitors such as sotorasib, the first FDA-approved drug targeting KRAS G12C, or adagrasib, initiating a new exciting era. However, treatment with targeted KRAS G12C inhibitors also leads to resistance, and understanding the possible mechanisms of resistance and which drugs could be useful to overcome it is key. Among others, KRAS G12C (ON) tricomplex inhibitors and different combination therapy strategies are being analyzed in clinical trials. Another area of interest is the potential role of co-mutations in treatment selection, particularly immunotherapy. The best first-line strategy remains to be determined and, due to the heterogeneity of KRAS, is likely to be based on combination therapies.

Metabolic synthetic lethality by targeting NOP56 and mTOR in KRAS-mutant lung cancer

Background

Oncogenic KRAS mutations are prevalent in human cancers, but effective treatment of KRAS-mutant malignancies remains a major challenge in the clinic. Increasing evidence suggests that aberrant metabolism plays a central role in KRAS-driven oncogenic transformation. The aim of this study is to identify selective metabolic dependency induced by mutant KRAS and to exploit it for the treatment of the disease.

Method

We performed an integrated analysis of RNAi- and CRISPR-based functional genomic datasets (n = 5) to identify novel genes selectively required for KRAS-mutant cancer. We further screened a customized library of chemical inhibitors for candidates that are synthetic lethal with NOP56 depletion. Functional studies were carried out by genetic knockdown using siRNAs and shRNAs, knockout using CRISPR/Cas9, and/or pharmacological inhibition, followed by cell viability and apoptotic assays. Protein expression was determined by Western blot. Metabolic ROS was measured by flow cytometry-based quantification.

Results

We demonstrated that nucleolar protein 5A (NOP56), a core component of small nucleolar ribonucleoprotein complexes (snoRNPs) with an essential role in ribosome biogenesis, confers a metabolic dependency by regulating ROS homeostasis in KRAS-mutant lung cancer cells and that NOP56 depletion causes synthetic lethal susceptibility to inhibition of mTOR. Mechanistically, cancer cells with reduced NOP56 are subjected to higher levels of ROS and rely on mTOR signaling to balance oxidative stress and survive. We also discovered that IRE1α-mediated unfolded protein response (UPR) regulates this process by activating mTOR through p38 MAPK. Consequently, co-targeting of NOP56 and mTOR profoundly enhances KRAS-mutant tumor cell death in vitro and in vivo.

Conclusions

Our findings reveal a previously unrecognized mechanism in which NOP56 and mTOR cooperate to play a homeostatic role in the response to oxidative stress and suggest a new rationale for the treatment of KRAS-mutant cancers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02240-5.

A Breakthrough Brought about by Targeting KRASG12C: Nonconformity Is Punished

Simple Summary

KRAS is the most common oncogene in human cancers and has long been considered ‘‘undruggable’’—that is, until recently, when covalent inhibitors that selectively target KRAS^G12C substitution were developed. The satisfactory results of multicenter clinical trials has led to the recent approval of therapy with KRAS^G12C inhibitors. Although KRAS^G12C allele-specific drugs have greatly improved the clinical outlook for patients with KRAS^G12C tumors, particularly lung adenocarcinomas, in which the KRAS^G12C mutant is most prevalent compared with other KRAS mutations, inevitable challenges, such as intrinsic and acquired drug resistance, must be overcome to maximize the efficacy of KRAS^G12C inhibitor therapy. Recent studies have shown that compensatory signaling pathways, such as the PI3K/AKT/mTOR pathway, and epigenetic reprogramming, e.g., epithelial-to-mesenchymal transition (EMT), are common mechanisms that mediate intrinsic resistance to KRAS^G12C inhibitors, whereas acquired resistance and ensuing recurrent disease can arise when cancer cells acquire secondary mutations in the KRAS protein that impair the covalent binding of KRAS^G12C inhibitors. The identification and targeting of KRAS^G12C inhibitor resistance mechanisms holds promise for novel strategies to effectively treat patients with KRAS^G12C-mutant cancers.

Abstract

KRAS is the most frequently mutated oncogene in lung carcinomas, accounting for 25% of total incidence, with half of them being KRAS^G12C mutations. In past decades, KRAS enjoyed the notorious reputation of being untargetable—that is, until the advent of G12C inhibitors, which put an end to this legend by covalently targeting the G12C (glycine to cysteine) substitution in the switch-II pocket of the protein, inhibiting the affinity of the mutant KRAS with GTP and subsequently the downstream signaling pathways, such as Raf/MEK/ERK. KRAS^G12C-selective inhibitors, e.g., the FDA-approved AMG510 and MRTX849, have demonstrated potent clinical efficacy and selectivity in patients with KRAS^G12C-driven cancers only, which spares other driver KRAS mutations (e.g., G12D/V/S, G13D, and Q61H) and has ushered in an unprecedented breakthrough in the field in recent decades. However, accumulating evidence from preclinical and clinical studies has shown that G12C-targeted therapeutics as single agents are inevitably thwarted by drug resistance, a persistent problem associated with targeted therapies. A promising strategy to optimize G12C inhibitor therapy is combination treatments with other therapeutic agents, the identification of which is empowered by the insightful appreciation of compensatory signaling pathways or evasive mechanisms, such as those that attenuate immune responses. Here, we review recent advances in targeting KRAS^G12C and discuss the challenges of KRAS^G12C inhibitor therapy, as well as future directions.

Targeting the undruggable oncogenic KRAS: the dawn of hope

KRAS mutations are the drivers of various cancers, including non-small cell lung cancer, colon cancer, and pancreatic cancer. Over the last 30 years, immense efforts have been made to inhibit KRAS mutants and oncogenic KRAS signaling using inhibitors. Recently, specific targeting of KRAS mutants with small molecules revived the hopes for successful therapies for lung, pancreatic, and colorectal cancer patients. Moreover, advances in gene editing, protein engineering, and drug delivery formulations have revolutionized cancer therapy regimens. New therapies aim to improve immune surveillance and enhance antitumor immunity by precisely targeting cancer cells harboring oncogenic KRAS. Here, we review recent KRAS-targeting strategies, their therapeutic potential, and remaining challenges to overcome. We also highlight the potential synergistic effects of various combinatorial therapies in preclinical and clinical trials.

KRAS and MET in non-small-cell lung cancer: two of the new kids on the 'drivers' block

Non-small-cell lung cancer (NSCLC) is a heterogeneous disease, and therapeutic management has advanced to identify various critical oncogenic mutations that promote lung cancer tumorigenesis. Subsequent studies have developed targeted therapies against these oncogenes in the hope of personalized treatment based on the tumor's molecular genomics. This review presents a comprehensive review of the biology, new therapeutic interventions, and resistance patterns of two well-defined subgroups, tumors with KRAS and MET alterations. We also discuss the status of molecular testing practices for these two key oncogenic drivers, considering the progressive introduction of next-generation sequencing (NGS) and RNA sequencing in regular clinical practice.

The Intriguing Thyroid Hormones-Lung Cancer Association as Exemplification of the Thyroid Hormones-Cancer Association: Three Decades of Evolving Research

Exemplifying the long-pursued thyroid hormones (TH)-cancer association, the TH-lung cancer association is a compelling, yet elusive, issue. The present narrative review provides background knowledge on the molecular aspects of TH actions, with focus on the contribution of TH to hallmarks of cancer. Then, it provides a comprehensive overview of data pertinent to the TH-lung cancer association garnered over the last three decades and identifies obstacles that need to be overcome to enable harnessing this association in the clinical setting. TH contribute to all hallmarks of cancer through integration of diverse actions, currently classified according to molecular background. Despite the increasingly recognized implication of TH in lung cancer, three pending queries need to be resolved to empower a tailored approach: (1) How to stratify patients with TH-sensitive lung tumors? (2) How is determined whether TH promote or inhibit lung cancer progression? (3) How to mimic the antitumor and/or abrogate the tumor-promoting TH actions in lung cancer? To address these queries, research should prioritize the elucidation of the crosstalk between TH signaling and oncogenic signaling implicated in lung cancer initiation and progression, and the development of efficient, safe, and feasible strategies leveraging this crosstalk in therapeutics.

Deep Radiotranscriptomics of Non-Small Cell Lung Carcinoma for Assessing Molecular and Histology Subtypes with a Data-Driven Analysis

Radiogenomic and radiotranscriptomic studies have the potential to pave the way for a holistic decision support system built on genomics, transcriptomics, radiomics, deep features and clinical parameters to assess treatment evaluation and care planning. The integration of invasive and routine imaging data into a common feature space has the potential to yield robust models for inferring the drivers of underlying biological mechanisms. In this non-small cell lung carcinoma study, a multi-omics representation comprised deep features and transcriptomics was evaluated to further explore the synergetic and complementary properties of these diverse multi-view data sources by utilizing data-driven machine learning models. The proposed deep radiotranscriptomic analysis is a feature-based fusion that significantly enhances sensitivity by up to 0.174 and AUC by up to 0.22, compared to the baseline single source models, across all experiments on the unseen testing set. Additionally, a radiomics-based fusion was also explored as an alternative methodology yielding radiomic signatures that are comparable to several previous publications in the field of radiogenomics. Furthermore, the machine learning multi-omics analysis based on deep features and transcriptomics achieved an AUC performance of up to 0.831 ± 0.09/0.925 ± 0.04 for the examined molecular and histology subtypes analysis, respectively. The clinical impact of such high-performing models can add prognostic value and lead to optimal treatment assessment by targeting specific oncogenes, namely the response of tyrosine kinase inhibitors of EGFR mutated or predicting the chemotherapy resistance of KRAS mutated tumors.

The Advance and Correlation of KRAS Mutation With the Fertility-Preservation Treatment of Endometrial Cancer in the Background of Molecular Classification Application

The annually increasing incidence of endometrial cancer in younger women has created a growing demand for fertility preservation. However, the diverse therapeutic efficacy among patients under the same histological subtype and the same tumor grade suggests the potential interference of the innate molecular characteristics. The molecular classification has now been applied in clinical practice and might help to stratify the endometrial cancer patients and individualize the therapy, but the candidates for the fertility-spared treatment are most likely to be subdivided in the subgroup lacking the specific signature. KRAS mutation has been linked to the malignant transition of the endometrium, while its role in molecular classification and fertility preservation is vague. Here, we mainly review the advance of molecular classification and the role of KRAS in endometrial cancer, as well as their correlation with fertility-preservation treatment.

In silico epitope prediction analyses highlight the potential for distracting antigen immunodominance with allogeneic cancer vaccines

Allogeneic cancer vaccines are designed to induce antitumor immune responses with the goal of impacting tumor growth. Typical allogeneic cancer vaccines are produced by expansion of established cancer cell lines, transfection with vectors encoding immunostimulatory cytokines, and lethal irradiation. More than 100 clinical trials have investigated the clinical benefit of allogeneic cancer vaccines in various cancer types. Results show limited therapeutic benefit in clinical trials and currently there are no FDA approved allogeneic cancer vaccines. We used recently developed bioinformatics tools including the pVAC-seq suite of software tools to analyze DNA/RNA sequencing data from the TCGA to examine the repertoire of antigens presented by a typical allogeneic cancer vaccine, and to simulate allogeneic cancer vaccine clinical trials. Specifically, for each simulated clinical trial we modeled the repertoire of antigens presented by allogeneic cancer vaccines consisting of three hypothetical cancer cell lines to 30 patients with the same cancer type. Simulations were repeated ten times for each cancer type. Each tumor sample in the vaccine and the vaccine recipient was subjected to HLA typing, differential expression analyses for tumor associated antigens (TAAs), germline variant calling, and neoantigen prediction. These analyses provided a robust, quantitative comparison between potentially beneficial TAAs and neoantigens versus distracting antigens present in the allogeneic cancer vaccines. We observe that distracting antigens greatly outnumber shared TAAs and neoantigens, providing one potential explanation for the lack of observed responses to allogeneic cancer vaccines. This analysis provides additional rationale for the redirection of efforts towards a personalized cancer vaccine approach.

Smoking signature is superior to programmed death-ligand 1 expression in predicting pathological response to neoadjuvant immunotherapy in lung cancer patients

Background

There is a paucity of biomarkers that can predict the degree of pathological response [e.g., pathological complete response (pCR) or major response (pMR)] to immunotherapy. Neoadjuvant immunotherapy provides an ideal setting for exploring responsive biomarkers because the pathological responses can be directly and accurately evaluated.

Methods

We retrospectively collected the clinicopathological characteristics and treatment outcomes of non-small cell lung cancer (NSCLC) patients who received neoadjuvant immunotherapy or chemo-immunotherapy followed by surgery between 2018 and 2020 at a large academic thoracic cancer center. Clinicopathological factors associated with pathological response were analyzed.

Results

A total of 39 patients (35 males and 4 females) were included. The most common histological subtype was lung squamous cell carcinoma (LUSC) (n=28, 71.8%), followed by lung adenocarcinoma (LUAD) (n=11, 28.2%). After neoadjuvant treatment, computed tomography (CT) scan-based evaluation showed poor agreement with the postoperatively pathological examination (weighted kappa =0.0225; P=0.795), suggesting the poor performance of CT scans in evaluating the response to immunotherapy. Importantly, we found that the smoking signature displayed a better performance than programmed death-ligand 1 (PD-L1) expression in predicting the pathological response (area under the curve: 0.690 vs. 0.456; P=0.0259), which might have resulted from increased tumor mutational burden (TMB) and/or microsatellite instability (MSI) relating to smoking exposure.

Conclusions

These findings suggest that CT scan-based evaluation is not able to accurately reflect the pathological response to immunotherapy and that smoking signature is a superior marker to PD-L1 expression in predicting the benefit of immunotherapy in NSCLC patients.

Diagnostic, Predictive, and Prognostic Biomarkers in Non-Small Cell Lung Cancer (NSCLC) Management

Lung cancer is the leading cause of cancer-related deaths worldwide. Despite growing efforts for its early detection by screening populations at risk, the majority of lung cancer patients are still diagnosed in an advanced stage. The management of lung cancer has dramatically improved in the last decade and is no longer based on the "one-fits-all" paradigm or the general histological classification of non-small cell versus small cell lung cancer. Emerging options of targeted therapies and immunotherapies have shifted the management of lung cancer to a more personalized treatment approach, significantly influencing the clinical course and outcome of the disease. Molecular biomarkers have emerged as valuable tools in the prognosis and prediction of therapy response. In this review, we discuss the relevant biomarkers used in the clinical management of lung tumors, from diagnosis to prognosis. We also discuss promising new biomarkers, focusing on non-small cell lung cancer as the most abundant type of lung cancer.

ABL allosteric inhibitors synergize with statins to enhance apoptosis of metastatic lung cancer cells

Targeting mitochondrial metabolism has emerged as a treatment option for cancer patients. The ABL tyrosine kinases promote metastasis, and enhanced ABL signaling is associated with a poor prognosis in lung adenocarcinoma patients. Here we show that ABL kinase allosteric inhibitors impair mitochondrial integrity and decrease oxidative phosphorylation. To identify metabolic vulnerabilities that enhance this phenotype, we utilized a CRISPR/Cas9 loss-of-function screen and identified HMG-CoA reductase, the rate-limiting enzyme of the mevalonate pathway and target of statin therapies, as a top-scoring sensitizer to ABL inhibition. Combination treatment with ABL allosteric inhibitors and statins decreases metastatic lung cancer cell survival in vitro in a synergistic manner. Notably, combination therapy in mouse models of lung cancer brain metastasis and therapy resistance impairs metastatic colonization with a concomitant increase in animal survival. Thus, metabolic combination therapy might be effective to decrease metastatic outgrowth, leading to increased survival for lung cancer patients with advanced disease.

Metabolic reprogramming in tumors is an adaptation that generates vulnerabilities that can be exploited for developing new therapies. Here Luttman et al. identify synergism between ABL allosteric inhibitors and lipophilic statins to impair metastatic lung cancer cell outgrowth and colonization, leading to increased survival in mouse models of advanced disease.

Synergistic effects of FGFR1 and PLK1 inhibitors target a metabolic liability in KRAS-mutant cancer

KRAS oncoprotein is commonly mutated in human cancer, but effective therapies specifically targeting KRAS-driven tumors remain elusive. Here, we show that combined treatment with fibroblast growth factor receptor 1 (FGFR1) and polo-like kinase 1 (PLK1) inhibitors evoke synergistic cytotoxicity in KRAS-mutant tumor models in vitro and in vivo. Pharmacological and genetic suppression of FGFR1 and PLK1 synergizes to enhance anti-proliferative effects and cell death in KRAS-mutant lung and pancreatic but not colon nor KRAS wild-type cancer cells. Mechanistically, co-targeting FGFR1 and PLK1 upregulates reactive oxygen species (ROS), leading to oxidative stress-activated c-Jun N-terminal kinase (JNK)/p38 pathway and E2F1-induced apoptosis. We further delineate that autophagy protects from PLK1/FGFR1 inhibitor cytotoxicity and that antagonizing the compensation mechanism by clinically approved chloroquine fully realizes the therapeutic potential of PLK1 and FGFR1 targeting therapy, producing potent and durable responses in KRAS-mutant patient-derived xenografts and a genetically engineered mouse model of Kras-induced lung adenocarcinoma. These results suggest a previously unappreciated role for FGFR1 and PLK1 in the surveillance of metabolic stress and demonstrate a synergistic drug combination for treating KRAS-mutant cancer.

On target: Rational approaches to KRAS inhibition for treatment of non-small cell lung carcinoma

Non-small cell lung carcinoma (NSCLC) is a leading cause of cancer death. Approximately one-third of patients with NSCLC have a KRAS mutation. KRAS^G12C, the most common mutation, is found in ~13% of patients. While KRAS was long considered 'undruggable', several novel direct KRAS^G12C inhibitors have shown encouraging signs of efficacy in phase I/II trials and one of these (sotorasib) has recently been approved by the US Food and Drug Administration. This review examines the role of KRAS mutations in NSCLC and the challenges in targeting KRAS. Based on specific KRAS biology, it reports exciting progress, exploring the use of novel direct KRAS inhibitors as monotherapy or in combination with other targeted therapies, chemotherapy, and immunotherapy.

Cytotoxic activity of KRAS inhibitors in combination with chemotherapeutics

INTRODUCTION

KRAS is the most frequently mutated oncogenic driver in pancreatic, lung, and colon cancer. Recently, KRAS inhibitors in clinical use show promising activity but most responses are partial and drug resistance develops. The use of therapeutics in combination with KRAS inhibitors are expected to improve outcomes.

AREAS COVERED

This review describes the KRAS G12C mutation-specific inhibitors and the SOS1-targeting inhibitors that reduce the GTP-loading of wildtype and mutated KRAS. Both types of compounds reduce tumor cell proliferation in vitro and in vivo. The combinations of the various KRAS inhibitors with downstream signaling effectors, modulators of KRAS-associated metabolic alterations and chemotherapeutics are summarized.

EXPERT OPINION

The clinical potency of mutated KRAS-specific inhibitors needs to be improved by suitable drug combinations. Inhibition of downstream signaling cascades increases toxicity and other combinations exploited comprise G12C-directed inhibitors with SOS1 inhibitors, glucose/glutamine metabolic modulators, classical chemotherapeutics, and others. The most suitable inhibitor combinations corroborated in preclinical development await clinical verification.