KMT2D deficiency drives lung squamous cell carcinoma and hypersensitivity to RTK-RAS inhibition

Histone-methyltransferase KMT2D deficiency impairs the Fanconi anemia/BRCA pathway upon glycolytic inhibition in squamous cell carcinoma

Histone lysine methyltransferase 2D (KMT2D) is the most frequently mutated epigenetic modifier in head and neck squamous cell carcinoma (HNSCC). However, the role of KMT2D in HNSCC tumorigenesis and whether its mutations confer any therapeutic vulnerabilities remain unknown. Here we show that KMT2D deficiency promotes HNSCC growth through increasing glycolysis. Additionally, KMT2D loss decreases the expression of Fanconi Anemia (FA)/BRCA pathway genes under glycolytic inhibition. Mechanistically, glycolytic inhibition facilitates the occupancy of KMT2D to the promoter/enhancer regions of FA genes. KMT2D loss reprograms the epigenomic landscapes of FA genes by transiting their promoter/enhancer states from active to inactive under glycolytic inhibition. Therefore, combining the glycolysis inhibitor 2-DG with DNA crosslinking agents or poly (ADP-ribose) polymerase (PARP) inhibitors preferentially inhibits tumor growth of KMT2D-deficient mouse HNSCC and patient-derived xenografts (PDXs) harboring KMT2D-inactivating mutations. These findings provide an epigenomic basis for developing targeted therapies for HNSCC patients with KMT2D-inactivating mutations.

WWP1 inhibition increases SHP2 inhibitor efficacy in colorectal cancer

Protein tyrosine phosphatase SHP2 activates RAS signaling, which is a novel target for colorectal cancer (CRC) therapy. However, SHP2 inhibitor monotherapy is ineffective for metastatic CRC and a combination therapy is required. In this study, we aimed to improve the antitumor efficacy of SHP2 inhibition and try to explore the resistance mechanism of SHP2 inhibitor. Results showed that WWP1 promoted the proliferation of CRC cells. Genetic or pharmacological inhibition of WWP1 enhanced the effect of SHP2 inhibitor in suppressing tumor growth in vitro and in vivo. WWP1 may mediate feedback reactivation of AKT signaling following SHP2 inhibition. Furthermore, nomogram models constructed with IHC expression of WWP1 and SHP2 greatly improved the accuracy of prognosis prediction for patients with CRC. Our findings indicate that WWP1 inhibitor I3C can synergize with SHP2 inhibitor and is expected to be a new strategy for clinical trials in treating advanced CRC patients.

FAM20A: a potential diagnostic biomarker for lung squamous cell carcinoma

Background

Lung squamous cell carcinoma (LUSC) ranks among the carcinomas with the highest incidence and dismal survival rates, suffering from a lack of effective therapeutic strategies. Consequently, biomarkers facilitating early diagnosis of LUSC could significantly enhance patient survival. This study aims to identify novel biomarkers for LUSC.

Methods

Utilizing the TCGA, GTEx, and CGGA databases, we focused on the gene encoding Family with Sequence Similarity 20, Member A (FAM20A) across various cancers. We then corroborated these bioinformatic predictions with clinical samples. A range of analytical tools, including Kaplan-Meier, MethSurv database, Wilcoxon rank-sum, Kruskal-Wallis tests, Gene Set Enrichment Analysis, and TIMER database, were employed to assess the diagnostic and prognostic value of FAM20A in LUSC. These tools also helped evaluate immune cell infiltration, immune checkpoint genes, DNA repair-related genes, DNA methylation, and tumor-related pathways.

Results

FAM20A expression was found to be significantly reduced in LUSC, correlating with lower survival rates. It exhibited a negative correlation with key proteins in DNA repair signaling pathways, potentially contributing to LUSC's radiotherapy resistance. Additionally, FAM20A showed a positive correlation with immune checkpoints like CTLA-4, indicating potential heightened sensitivity to immunotherapies targeting these checkpoints.

Conclusion

FAM20A emerges as a promising diagnostic and prognostic biomarker for LUSC, offering potential clinical applications.

Tumor initiation and early tumorigenesis: molecular mechanisms and interventional targets

Tumorigenesis is a multistep process, with oncogenic mutations in a normal cell conferring clonal advantage as the initial event. However, despite pervasive somatic mutations and clonal expansion in normal tissues, their transformation into cancer remains a rare event, indicating the presence of additional driver events for progression to an irreversible, highly heterogeneous, and invasive lesion. Recently, researchers are emphasizing the mechanisms of environmental tumor risk factors and epigenetic alterations that are profoundly influencing early clonal expansion and malignant evolution, independently of inducing mutations. Additionally, clonal evolution in tumorigenesis reflects a multifaceted interplay between cell-intrinsic identities and various cell-extrinsic factors that exert selective pressures to either restrain uncontrolled proliferation or allow specific clones to progress into tumors. However, the mechanisms by which driver events induce both intrinsic cellular competency and remodel environmental stress to facilitate malignant transformation are not fully understood. In this review, we summarize the genetic, epigenetic, and external driver events, and their effects on the co-evolution of the transformed cells and their ecosystem during tumor initiation and early malignant evolution. A deeper understanding of the earliest molecular events holds promise for translational applications, predicting individuals at high-risk of tumor and developing strategies to intercept malignant transformation.

Metabolism pathway-based subtyping in endometrial cancer: An integrated study by multi-omics analysis and machine learning algorithms

Endometrial cancer (EC), the second most common malignancy in the female reproductive system, has garnered increasing attention for its genomic heterogeneity, but understanding of its metabolic characteristics is still poor. We explored metabolic dysfunctions in EC through a comprehensive multi-omics analysis (RNA-seq datasets from The Cancer Genome Atlas [TCGA], Cancer Cell Line Encyclopedia [CCLE], and GEO datasets; the Clinical Proteomic Tumor Analysis Consortium [CPTAC] proteomics; CCLE metabolomics) to develop useful molecular targets for precision therapy. Unsupervised consensus clustering was performed to categorize EC patients into three metabolism-pathway-based subgroups (MPSs). These MPS subgroups had distinct clinical prognoses, transcriptomic and genomic alterations, immune microenvironment landscape, and unique patterns of chemotherapy sensitivity. Moreover, the MPS2 subgroup had a better response to immunotherapy. Finally, three machine learning algorithms (LASSO, random forest, and stepwise multivariate Cox regression) were used for developing a prognostic metagene signature based on metabolic molecules. Thus, a 13-hub gene-based classifier was constructed to predict patients' MPS subtypes, offering a more accessible and practical approach. This metabolism-based classification system can enhance prognostic predictions and guide clinical strategies for immunotherapy and metabolism-targeted therapy in EC.

Somatic KMT2D loss-of-function mutations in lung squamous cell carcinoma: a single-center cohort study

Background

The significant progress has been made in targeted therapy for lung adenocarcinoma (LUAD) in the past decade. Only few targeted therapeutics have yet been approved for the treatment of lung squamous cell carcinoma (LUSC). Several higher frequency of gene alterations are identified as potentially actionable in LUSC. Our work aimed to explore the complex interplay of multiple genetic alterations and pathways contributing to the pathogenesis of LUSC, with a very low frequency of a single driver molecular alterations to develop more effective therapeutic strategies in the future.

Methods

We retrospectively analyzed the targeted next-generation sequencing (NGS) data (approximately 600 genes) of 335 patients initially diagnosed with non-small cell lung cancer (NSCLC) at our institution between January 2019 and March 2023 and explored the somatic genome alteration difference between LUSC and LUAD.

Results

We analyzed that the presence of loss-of-function (LoF) mutations (nonsense, frameshift, and splice-site variants) in histone-lysine N-methyltransferase 2D (KMT2D) was much more prevalent in LUSC (11/53, 20.8%) than in LUAD (6/282, 2.1%). Moreover, our data indicated TP53 co-mutated with KMT2D LoF in 90.9% (10/11) LUSC and 33.3% (2/6) LUAD. Notably, the mutation allele fraction (MAF) of KMT2D was very similar to that of TP53 in the co-mutated cases. Genomic profiling of driver gene mutations of NSCLC showed that 81.8% (9/11) of the patients with LUSC with KMT2D LoF mutations had PIK3CA amplification and/or FGFR1 amplification.

Conclusions

Our results prompted that somatic LoF mutations of KMT2D occur frequently in LUSC, but are less frequent in LUAD and therefore may potentially contribute to the pathogenesis of LUSC. Concurrent TP53 mutations, FGFR1 amplification, and PIK3CA amplification are very common in LUSC cases with KMT2D LoF mutations. It needs more deeper investigation on the interplay of the genes and pathways and uses larger cohorts in the future.

Methylation of the chromatin modifier KMT2D by SMYD2 contributes to therapeutic response in hormone-dependent breast cancer

Activating mutations in PIK3CA are frequently found in estrogen-receptor-positive (ER+) breast cancer, and the combination of the phosphatidylinositol 3-kinase (PI3K) inhibitor alpelisib with anti-ER inhibitors is approved for therapy. We have previously demonstrated that the PI3K pathway regulates ER activity through phosphorylation of the chromatin modifier KMT2D. Here, we discovered a methylation site on KMT2D, at K1330 directly adjacent to S1331, catalyzed by the lysine methyltransferase SMYD2. SMYD2 loss attenuates alpelisib-induced KMT2D chromatin binding and alpelisib-mediated changes in gene expression, including ER-dependent transcription. Knockdown or pharmacological inhibition of SMYD2 sensitizes breast cancer cells, patient-derived organoids, and tumors to PI3K/AKT inhibition and endocrine therapy in part through KMT2D K1330 methylation. Together, our findings uncover a regulatory crosstalk between post-translational modifications that fine-tunes KMT2D function at the chromatin. This provides a rationale for the use of SMYD2 inhibitors in combination with PI3Kα/AKT inhibitors in the treatment of ER+/PIK3CA mutant breast cancer.

A role for pH dynamics regulating transcription factor DNA binding selectivity

Intracellular pH (pHi) dynamics regulates diverse cell processes such as proliferation, dysplasia, and differentiation, often mediated by the protonation state of a functionally critical histidine residue in endogenous pH sensing proteins. How pHi dynamics can directly regulate gene expression and whether transcription factors can function as pH sensors has received limited attention. We tested the prediction that transcription factors with a histidine in their DNA binding domain (DBD) that forms hydrogen bonds with nucleotides can have pH-regulated activity, which is relevant to more than 85 transcription factors in distinct families, including FOX, KLF, SOX and MITF/Myc. Focusing on FOX family transcription factors, we used unbiased SELEX-seq to identify pH-dependent DNA binding motif preferences, then confirm pH-regulated binding affinities for FOXC2, FOXM1, and FOXN1 to a canonical FkhP DNA motif that are 2.5 to 7.5 greater at pH 7.0 compared with pH 7.5. For FOXC2, we also find greater activity for an FkhP motif at lower pHi in cells and that pH-regulated binding and activity are dependent on a conserved histidine (His122) in the DBD. RNA-seq with FOXC2 also reveals pH-dependent differences in enriched promoter motifs. Our findings identify pH-regulated transcription factor-DNA binding selectivity with relevance to how pHi dynamics can regulate gene expression for myriad cell behaviours.

Common skin cancers and their association with other non-cutaneous primary malignancies: a review of the literature

It has long been recognized that a history of skin cancer puts one at risk for additional primary skin cancers. However, more variable data exists for the risk of developing a non-cutaneous primary cancer following a diagnosis of skin cancer. The data are most variable for Basal Cell Carcinoma (BCC), the most common and least aggressive type of skin cancer. While early studies imply that BCC does not impart a larger risk of other primary non-cutaneous cancers, more recent studies with larger populations suggest otherwise. The cancers most significantly associated with BCC are lip, oropharyngeal, and salivary gland cancer. There is also burgeoning evidence to suggest a link between BCC and prostate, breast, and colorectal cancer, but more data are needed to draw a concrete conclusion. Squamous Cell Carcinoma (SCC), the second most common type of skin cancer, has a slightly more defined risk to other non-cutaneous primary malignancies. There is a notable link between SCC and non-Hodgkin's lymphoma (NHL), possibly due to immunosuppression. There is also an increased risk of other cancers derived from squamous epithelium following SCC, including oropharyngeal, lip, and salivary gland cancer. Some studies also suggest an increased risk of respiratory tract cancer following SCC, possibly due to shared risk factors. Melanoma, a more severe type of skin cancer, shows a well-defined risk of additional primary non-cutaneous malignancies. The most significant of these risks include NHL, thyroid cancer, prostate cancer, and breast cancer along with a host of other cancers. Each of these three main skin cancer types has a profile of genetic mutations that have also been linked to non-cutaneous malignancies. In this review, we discuss a selection of these genes to highlight the complex interplay between different tumorigenesis processes.

Clinical significance of miR-9-5p in NSCLC and its relationship with smoking

Purpose

Dysregulated expression of microRNA (miRNAs) in lung cancer has been wildly reported. The clinicopathologic significance of miR-9-5p in non-small-cell lung cancer (NSCLC) patients and its effect on NSCLC progression were explored in this study.

Patients and methods

A total of 76 NSCLC patients were included. miR-9-5p expression was evaluated by real-time quantitative polymerase chain reaction (RT-qPCR). Then, in vitro experiments including cell growth curve assays, colony formation assays, and transwell migration assays were performed. Further clinicopathological and prognostic values were explored using bioinformatics analysis of the TCGA database.

Results

miR-9-5p expression was significantly increased in tumor tissues (both P < 0.0001). miR-9-5p expression was relatively higher in larger tumors (P = 0.0327) and in lung squamous carcinoma (LUSC) (P = 0. 0143). In addition, miR-9-5p was significantly upregulated in the normal lung tissues of cigarette smokers (P = 0.0099). In vitro, miR-9-5p was correlated with cell proliferation and migration. After that, bioinformatics analysis of the TCGA database indicated that miR-9-5p was correlated with tumor size (P = 0.0022), lymphatic metastasis (P = 0.0141), LUSC (P < 0.0001), and smoking history (P < 0.0001). Finally, a prognostic study indicated high miR-9-5p expression was correlated with poor prognosis in LUAD (P = 0.0121).

Conclusion

Upregulation of miR-9-5p may have an oncogenic effect in NSCLC and may be related to smoking. The conclusion of this study may help find new prognostic and therapeutic targets for NSCLC and the exploration of the relationship between smoking and lung cancer.

KMT2 (MLL) family of methyltransferases in head and neck squamous cell carcinoma: A systematic review

BACKGROUND

The involvement of the KMT2 methyltransferase family in the pathogenesis of head and neck squamous cell carcinoma (HNSCC) remains elusive.

METHOD

This study adhered to the PRISMA guidelines, employing a search strategy in the LIVIVO, PubMed, Scopus, Embase, Web of Science, and Google Scholar databases. The methodological quality of the studies was assessed by the Joanna Briggs Institute.

RESULTS

A total of 33 studies involving 4294 individuals with HNSCC were included in this review. The most important alteration was the high mutational frequency in the KMT2C and KMT2D genes, with reported co-occurrence. The expression of the KMT2D gene exhibited considerable heterogeneity across the studies, while limited data was available for the remaining genes.

CONCLUSIONS

KMT2C and KMT2D genes seem to have tumor suppressor activities, with involvement of cell cycle inhibitors, regulating different pathways that can lead to tumor progression, disease aggressiveness, and DNA damage accumulation.

Anoikis-related CTNND1 is associated with immuno-suppressive tumor microenvironment and predicts unfavorable immunotherapeutic outcome in non-small cell lung cancer

Background: Immunotherapy has greatly changed the treatment of advanced non-small cell lung cancer (NSCLC). Anoikis is a programmed cell death process associated with cancer. However, the correlation between anoikis-related genes and the tumor microenvironment (TME) features and immunotherapeutic outcome in NSCLC has not been fully explored. Methods: The bulk and single-cell transcriptome data of NSCLC were downloaded from TCGA and GEO databases. The distribution of anoikis-related genes on different cell types at the single-cell level was analyzed, and these genes specifically expressed by tumor cells and immunotherapy-related were further extracted. Next, the candidate gene CTNND1 was identified and its correlations with the TME features and immunotherapeutic outcome in NSCLC were explored in multiple public cohorts. Finally, an in-house cohort was used to determine the CTNND1 expression and immuno-correlation in NSCLC. Results: At single-cell atlas, we found that anoikis-related genes expressed specifically in tumor cells of NSCLC. By intersecting anoikis-related genes, immunotherapy-associated genes, and the genes expressed in tumor cells, we obtained a special biomarker CTNND1. In addition, cell-cell communication analysis revealed that CTNND1+ tumor cells communicated with immune subpopulations frequently. Moreover, we found that high expression of CTNND1 was related to immuno-suppressive status of NSCLC. The expression of CTNND1 and its immuno-correlation were also validated, and the results showed that CTNND1 was highly expressed in NSCLC tissues and tumors with high CTNND1 expression accompanied with low CD8+ T cells infiltration. Conclusions: Overall, our study reported that CTNND1 can be considered as a novel biomarker for the predication of immunotherapeutic responses and a potential target for NSCLC therapy.

Genome-Wide CRISPR Screens Identify Multiple Synthetic Lethal Targets That Enhance KRASG12C Inhibitor Efficacy

Non-small lung cancers (NSCLC) frequently (∼30%) harbor KRAS driver mutations, half of which are KRASG12C. KRAS-mutant NSCLC with comutated STK11 and/or KEAP1 is particularly refractory to conventional, targeted, and immune therapy. Development of KRASG12C inhibitors (G12Ci) provided a major therapeutic advance, but resistance still limits their efficacy. To identify genes whose deletion augments efficacy of the G12Cis adagrasib (MRTX-849) or adagrasib plus TNO155 (SHP2i), we performed genome-wide CRISPR/Cas9 screens on KRAS/STK11-mutant NSCLC lines. Recurrent, potentially targetable, synthetic lethal (SL) genes were identified, including serine-threonine kinases, tRNA-modifying and proteoglycan synthesis enzymes, and YAP/TAZ/TEAD pathway components. Several SL genes were confirmed by siRNA/shRNA experiments, and the YAP/TAZ/TEAD pathway was extensively validated in vitro and in mice. Mechanistic studies showed that G12Ci treatment induced gene expression of RHO paralogs and activators, increased RHOA activation, and evoked ROCK-dependent nuclear translocation of YAP. Mice and patients with acquired G12Ci- or G12Ci/SHP2i-resistant tumors showed strong overlap with SL pathways, arguing for the relevance of the screen results. These findings provide a landscape of potential targets for future combination strategies, some of which can be tested rapidly in the clinic.

SIGNIFICANCE

Identification of synthetic lethal genes with KRASG12C using genome-wide CRISPR/Cas9 screening and credentialing of the ability of TEAD inhibition to enhance KRASG12C efficacy provides a roadmap for combination strategies. See related commentary by Johnson and Haigis, p. 4005.

Heterozygous Kmt2d loss diminishes enhancers to render medulloblastoma cells vulnerable to combinatory inhibition of lysine demethylation and oxidative phosphorylation

The histone H3 lysine 4 (H3K4) methyltransferase KMT2D (also called MLL4) is one of the most frequently mutated epigenetic modifiers in medulloblastoma (MB) and other types of cancer. Notably, heterozygous loss of KMT2D is prevalent in MB and other cancer types. However, what role heterozygous KMT2D loss plays in tumorigenesis has not been well characterized. Here, we show that heterozygous Kmt2d loss highly promotes MB driven by heterozygous loss of the MB suppressor gene Ptch in mice. Heterozygous Kmt2d loss upregulated tumor-promoting programs, including oxidative phosphorylation and G-protein-coupled receptor signaling, in Ptch-mutant-driven MB genesis. Mechanistically, both downregulation of the transcription-repressive tumor suppressor gene NCOR2 by heterozygous Kmt2d loss and upregulation of the oncogene MycN by heterozygous Ptch loss increased the expression of tumor-promoting genes. Moreover, heterozygous Kmt2d loss extensively diminished enhancer signals (e.g., H3K27ac) and H3K4me3 signature, including those for tumor suppressor genes (e.g., Ncor2). Combinatory pharmacological inhibition of oxidative phosphorylation and the H3K4 demethylase LSD1 drastically reduced tumorigenicity of MB cells bearing heterozygous Kmt2d loss. These findings reveal the mechanistic basis underlying the MB-promoting effect of heterozygous KMT2D loss, provide a rationale for a therapeutic strategy for treatment of KMT2D-deficient MB, and have mechanistic implications for the molecular pathogenesis of other types of cancer bearing heterozygous KMT2D loss.

SHP2: A Pleiotropic Target at the Interface of Cancer and Its Microenvironment

The protein phosphatase SHP2/PTPN11 has been reported to be a key modulator of proliferative pathways in a wide range of malignancies. Intriguingly, SHP2 has also been described as a critical regulator of the tumor microenvironment. Based on this evidence SHP2 is considered a multifaceted target in cancer, spurring the notion that the development of direct inhibitors of SHP2 would provide the twofold benefit of tumor intrinsic and extrinsic inhibition. In this review, we will discuss the role of SHP2 in cancer and the tumor microenvironment, and the clinical strategies in which SHP2 inhibitors are leveraged as combination agents to improve therapeutic response.

SIGNIFICANCE

The SHP2 phosphatase functions as a pleiotropic factor, and its inhibition not only hinders tumor growth but also reshapes the tumor microenvironment. Although their single-agent activity may be limited, SHP2 inhibitors hold the potential of being key combination agents to enhance the depth and the durability of tumor response to therapy.

Identification of prognosis-related lncRNAs and cell validation in lung squamous cell carcinoma based on TCGA data

Objective

To discern long non-coding RNAs (lncRNAs) with prognostic relevance in the context of lung squamous cell carcinoma (LUSC), we intend to predict target genes by leveraging The Cancer Genome Atlas (TCGA) repository. Subsequently, we aim to investigate the proliferative potential of critical lncRNAs within the LUSC milieu.

Methods

DESeq2 was employed to identify differentially expressed genes within the TCGA database. Following this, we utilized both univariate and multivariate Cox regression analyses to identify lncRNAs with prognostic relevance. Noteworthy lncRNAs were selected for validation in cell lines. The intracellular localization of these lncRNAs was ascertained through nucleocytoplasmic isolation experiments. Additionally, the impact of these lncRNAs on cellular proliferation, invasion, and migration capabilities was investigated using an Antisense oligonucleotides (ASO) knockdown system.

Results

Multivariate Cox regression identified a total of 12 candidate genes, consisting of seven downregulated lncRNAs (BRE-AS1, CCL15-CCL14, DNMBP-AS1, LINC00482, LOC100129034, MIR22HG, PRR26) and five upregulated lncRNAs (FAM83A-AS1, LINC00628, LINC00923, LINC01341, LOC100130691). The target genes associated with these lncRNAs exhibit significant enrichment within diverse biological pathways, including metabolic processes, cancer pathways, MAPK signaling, PI3K-Akt signaling, protein binding, cellular components, cellular transformation, and other functional categories. Furthermore, nucleocytoplasmic fractionation experiments demonstrated that LINC00923 and LINC01341 are predominantly localized within the cellular nucleus. Subsequent investigations utilizing CCK-8 assays and colony formation assays revealed that the knockdown of LINC00923 and LINC01341 effectively suppressed the proliferation of H226 and H1703 cells. Additionally, transwell assays showed that knockdown of LINC00923 and LINC01341 significantly attenuated the invasive and migratory capacities of H226 and H1703 cells.

Conclusion

This study has identified 12 candidate lncRNA associated with prognostic implications, among which LINC00923 and LINC01341 exhibit potential as markers for the prediction of LUSC outcomes.

TNFR1 and TNFR2, Which Link NF-κB Activation, Drive Lung Cancer Progression, Cell Dedifferentiation, and Metastasis

TNFR1 and TNFR2, encoded by TNFRSF1A and TNFRSF1B, respectively, are the most well-characterized members among the TNFR superfamily. TNFR1 is expressed in most cell types, while TNFR2 has been reported to be preferentially expressed in leukocytes. Lung cancer remains the leading cause of cancer mortality worldwide but TNFRs' activities in lung cancer development have not been fully evaluated. Recently, overexpressed TNFR1 was reported in a large proportion of human lung squamous cell carcinomas. Increased TNFR1 coupled with increased UBCH10 caused lung SCC cell dedifferentiation with epithelial-mesenchymal transition features and the metastasis in a combined spontaneous lung SCC and TNFR1 transgenic mouse model. UBCH10, an E2 ubiquitin-conjugating enzyme that is an oncogene, increased Sox2, c-Myc, Twist1, and Bcl2 levels. Increased TNFR1 upregulated UBCH10 expression by activating c-Rel and p65 NF-κB. Lung SCC patients overexpressing TNFRSF1A and one of these target genes died early compared to lung SCC patients expressing lower levels of these genes. Recently, we also revealed that TNFR2 was required for lung adenocarcinoma progression, delivering a signaling pathway of TNF/TNFR2/NF-κB-c-Rel, in which macrophage-produced ROS and TNF converted CD4 T cells to Foxp3 Treg cells, generating an immunosuppressive tumor microenvironment and promoting lung ADC progression. In human lung ADC cohorts, TNFRSF1B expression was highly correlated with TNF, FOXP3, and CD4 expression. Of note, TNF stimulated the activities of TNFR1 and TNFR2, two membrane-binding receptors, which accelerate tumorigenesis through diverse mechanisms. This review focuses on these new findings regarding the roles of TNFR1 and TNFR2 in lung SCC and ADC development in humans and mice, and highlights the potential therapeutic targets of human lung cancers.

"PRRX1-rearranged mesenchymal tumors": expanding the immunohistochemical profile and molecular spectrum of a recently described entity with the proposed revision of nomenclature

Since the publication of the 2020 World Health Organization classification of soft tissue and bone tumors, the classification of "fibroblastic" tumors has expanded to include a novel subset of tumors characterized by PRRX1::NCOA1/2 gene fusions. These tumors defy conventional classification and are morphologically distinct, characterized by a multi-nodular growth of bland spindle cells suspended in a myxo-collagenous stroma with mild cytologic atypia, "staghorn-like" vessels, and variable perivascular hyalinization. Mitotic activity is rare, and necrosis is not identified. Herein, we present six additional cases of PRRX1-rearranged mesenchymal tumors, including five cases with PRRX1::NCOA1 fusion and one case with PRRX1::KMT2D fusion. Three cases (3/6, 50%) demonstrated focal co-expression of S100 protein and SOX10, thereby expanding the immunohistochemical profile of this emerging entity. Like prior reported cases, there was no evidence of malignant behavior on short-term follow-up. The novel fusion, PRRX1::KMT2D, further expands the molecular spectrum of this entity and leads to a proposed revision of the provisional nomenclature to "PRRX1-rearranged mesenchymal tumor" to both accommodate non-NCOA1/2 fusion partners and allow for the possibility of partial neural or neuroectodermal differentiation.