Role of Tumor-Infiltrating B Cells in Clinical Outcome of Patients with Melanoma Treated With Dabrafenib Plus Trametinib

Determinants of resistance and response to melanoma therapy

Metastatic melanoma is among the most enigmatic advanced cancers to clinically manage despite immense progress in the way of available therapeutic options and historic decreases in the melanoma mortality rate. Most patients with metastatic melanoma treated with modern targeted therapies (for example, BRAFV600E/K inhibitors) and/or immune checkpoint blockade (for example, anti-programmed death 1 therapy) will progress, owing to profound tumor cell plasticity fueled by genetic and nongenetic mechanisms and dichotomous host microenvironmental influences. Here we discuss the determinants of tumor heterogeneity, mechanisms of therapy resistance and effective therapy regimens that hold curative promise.

Genomic and Transcriptomic Landscape of RET Wild-Type Medullary Thyroid Cancer and Potential Use of Mitogen-Activated Protein Kinase-Targeted Therapy

BACKGROUND

About 75% of medullary thyroid cancers (MTCs) are sporadic with 45% to 70% being driven by a RET mutation. Selpercatinib is an approved treatment for RET-mutated (mut RET ) MTC; however, treatments are needed for wild-type RET MTC (wt RET ). Genomic alterations and transcriptomic signatures of wt RET MTC may reveal new therapeutic insights.

STUDY DESIGN

We did a retrospective analysis of MTC samples submitted for DNA/RNA sequencing and programmed cell death ligand 1 expression using immunohistochemistry at a Clinical Laboratory Improvement Amendments/College of American Pathologists-certified laboratory. Tumor microenvironment immune cell fractions were estimated using RNA deconvolution (quanTIseq). Transcriptomic signatures of inflammation and MAP kinase pathway activation scores were calculated. Mann-Whitney U, chi-square, and Fisher's exact tests were applied (p values adjusted for multiple comparisons).

RESULTS

The 160-patient cohort included 108 mut RET and 52 wt RET MTC samples. wt RET tumors frequently harbored mitogen-activated protein kinase (MAPK) pathway mutations, including HRAS (42.31%), KRAS (15.7%), NF1 (6.7%), and BRAF (2%), whereas only 1 MAPK pathway mutation ( NF1 ) was identified among mut RET MTC. Recurrent mutations seen in wt RET MTC included MGA , VHL, APC , STK11 , and NFE2L2 . Increased transcriptional activation of the MAPK pathway was observed in patients with wt RET harboring mutations in MAPK genes. Although the frequency of programmed cell death ligand 1 expression was similar in wt RET and mut RET (10.2% vs 7%, p = 0.531), wt RET tumors were more often tumor mutational burden high (7.7% vs 0%, p = 0.011), and wt RET MTC exhibited higher expression of immune checkpoint genes.

CONCLUSIONS

We identified molecular alterations and immune-related features that distinguish wt RET from mut RET MTC. Although RET mutation drives MTC in the absence of other alterations, we showed that wt RET MTC frequently harbors MAPK pathway mutations. These findings may indicate a potential basis for MAPK-targeted therapy, possibly in combination with immuno-oncology agents for selected patients with wt RET MTC.

Pan-cancer analysis reveals the pro-oncogenic role of N6-methyladenosine (m6A)-regulated NTMT1 in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSC) is a common and fatal tumor with a bleak prognosis, posing a significant threat to human health. N6-methyladenosine (m6A) modification regulates tumor progression by modulating gene expression post-transcriptionally. Nevertheless, the specific function of m6A-modified tumor drivers in HNSC remains largely uncharted. In this study, we revealed the pro-oncogenic role of m6A-regulated NTMT1 in HNSC through comprehensive pan-cancer analysis and experimental validation. By scrutinizing the prognostic and expression profiles of NTMT1 across over 30 cancer types, we observed a significant association between NTMT1 and patient overall survival in ACC, HNSC, LAML, LGG, KIRC, and STAD. Moreover, we find a close correlation between NTMT1 and disease-free survival in ACC, HNSC, LUSC, UVM, KIRC, and STAD. NTMT1 exhibited dysregulation in 15 cancers, including CESC, CHOL, COAD, DLBC, GBM, HNSC, LGG, LIHC, PAAD, READ, SKCM, THYM, UCS, LAML, and TGCT. Integrated data underscored the critical involvement of NTMT1 in HNSC. Furthermore, the expression of NTMT1 was closely associated with tumor stage and immune infiltration in HNSC. Functionally, NTMT1 deficiency was demonstrated to significantly impede cell proliferation and cell-cycle progression in HNSC. Mechanistically, METTL3 was elucidated to mediate the epigenetic upregulation of NTMT1 in HNSC in an m6A-dependent manner, and the overexpression of METTL3 was shown to alleviate the inhibitory impact of downregulated NTMT1 on HNSC proliferation. In conclusion, our findings enhance our understanding of NTMT1's role across various cancer types and offer a rationale for clinically targeting NTMT1 as a therapeutic approach for HNSC.

Interleukin 17 signaling supports clinical benefit of dual CTLA-4 and PD-1 checkpoint inhibition in melanoma

Recent studies suggest that BRAFV600-mutated melanomas in particular respond to dual anti-programmed cell death protein 1 (PD-1) and anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4) immune checkpoint inhibition (ICI). Here we identified an over-representation of interleukin (IL)-17-type 17 helper T (TH17) gene expression signatures (GES) in BRAFV600-mutated tumors. Moreover, high baseline IL-17 GES consistently predicted clinical responses in dual-ICI-treated patient cohorts but not in mono anti-CTLA-4 or anti-PD-1 ICI cohorts. High IL-17 GES corresponded to tumor infiltration with T cells and neutrophils. Accordingly, high neutrophil infiltration correlated with clinical response specifically to dual ICI, and tumor-associated neutrophils also showed strong IL-17-TH17 pathway activity and T cell activation capacity. Both the blockade of IL-17A and the depletion of neutrophils impaired dual-ICI response and decreased T cell activation. Finally, high IL-17A levels in the blood of patients with melanoma indicated a higher global TH17 cytokine profile preceding clinical response to dual ICI but not to anti-PD-1 monotherapy, suggesting a future role as a biomarker for patient stratification.

Roles and mechanisms of tumour-infiltrating B cells in human cancer: a new force in immunotherapy

Immune checkpoint inhibitors (ICIs) targeting PD-1 or PD-L1 have emerged as a revolutionary treatment strategy for human cancer patients. However, as the response rate to ICI therapy varies widely among different types of tumours, we are beginning to gain insight into the mechanisms as well as biomarkers of therapeutic response and resistance. Numerous studies have highlighted the dominant role of cytotoxic T cells in determining the treatment response to ICIs. Empowered by recent technical advances, such as single-cell sequencing, tumour-infiltrating B cells have been identified as a key regulator in several solid tumours by affecting tumour progression and the response to ICIs. In the current review, we summarized recent advances regarding the role and underlying mechanisms of B cells in human cancer and therapy. Some studies have shown that B-cell abundance in cancer is positively associated with favourable clinical outcomes, while others have indicated that they are tumour-promoting, implying that the biological function of B cells is a complex landscape. The molecular mechanisms involved multiple aspects of the functions of B cells, including the activation of CD8+ T cells, the secretion of antibodies and cytokines, and the facilitation of the antigen presentation process. In addition, other crucial mechanisms, such as the functions of regulatory B cells (Bregs) and plasma cells, are discussed. Here, by summarizing the advances and dilemmas of recent studies, we depicted the current landscape of B cells in cancers and paved the way for future research in this field.

Tumour-infiltrating B cells: immunological mechanisms, clinical impact and therapeutic opportunities

Although immunotherapy research to date has focused largely on T cells, there is mounting evidence that tumour-infiltrating B cells and plasma cells (collectively referred to as tumour-infiltrating B lymphocytes (TIL-Bs)) have a crucial, synergistic role in tumour control. In many cancers, TIL-Bs have demonstrated strong predictive and prognostic significance in the context of both standard treatments and immune checkpoint blockade, offering the prospect of new therapeutic opportunities that leverage their unique immunological properties. Drawing insights from autoimmunity, we review the molecular phenotypes, architectural contexts, antigen specificities, effector mechanisms and regulatory pathways relevant to TIL-Bs in human cancer. Although the field is young, the emerging picture is that TIL-Bs promote antitumour immunity through their unique mode of antigen presentation to T cells; their role in assembling and perpetuating immunologically 'hot' tumour microenvironments involving T cells, myeloid cells and natural killer cells; and their potential to combat immune editing and tumour heterogeneity through the easing of self-tolerance mechanisms. We end by discussing the most promising approaches to enhance TIL-B responses in concert with other immune cell subsets to extend the reach, potency and durability of cancer immunotherapy.

A B-cell or a key player? The different roles of B-cells and antibodies in melanoma

The B‐cell system plays an important role in the melanoma immune response; however, consensus has yet to be reached in many facets. Here, we comprehensively review human studies only, due to fundamental differences in the humoral response with animal models. Tumour‐infiltrating B‐cells are associated with contradictory prognostic values, reflecting a lack of agreement between studies on cell subset classification and differences in the markers used, particularly the common use of a single marker not differentiating multiple subsets. Tertiary lymphoid structures (TLS) organise T‐cells and B‐cells within tumours to generate a local anti‐tumour response and TLS presence associates with improved survival in response to immune checkpoint blockade, in late‐stage disease. Autoantibody production is increased in melanoma patients and has been proposed as biomarkers for diagnosis, prognosis and treatment/toxicity response; however, no consistent targets are yet identified. The function of antibodies in an anti‐tumour response is determined by its isotype and subclass; IgG₄ is immune‐suppressive and robustly correlate with poor patient survival in melanoma. We conclude that the current B‐cell literature needs careful interpretation based on the methods used and that we need a consensus of markers to define B‐cells and associated lymphoid organs. Furthermore, future studies need to not only examine antibody targets, but also isotypes when considering functional roles.

Significance of TEAD Family in Diagnosis, Prognosis and Immune Response for Ovarian Serous Carcinoma

Purpose

To explore the molecular profiles of transcriptional enhanced associate domain (TEAD) family in ovarian serous carcinoma (OSC).

Methods

In this study, we use bioinformatics methods including GEPIA, GE-mini, Oncomine 3.0, Kaplan–Meier plotter, cBioPortal, WebGestalt, TIMER2.0 and DiseaseMeth2.0, and in vitro experimental RT-PCR to assess the expression profiles and prognostic significance of TEAD family in OSC.

Results

According to the bioinformatics analysis, TEAD family was abnormally expressed in OSC. In terms of prognosis, Kaplan–Meier plotter indicated that OSC patients with high level of TEAD4 showed poor overall survival (OS), progression-free survival (PFS) and post progression survival (PPS). TEAD family also had significantly diagnostic values for OSC patients. Tumor Immune Estimation Resource (TIMER) algorithm indicated that TEAD family was significantly associated with different types of infiltrating immune cells, including B cells, macrophages, dendritic cells, neutrophils, CD8+ T cells and CD4+ T cells. Gene set enrichment analysis of TEAD family-associated coexpression genes was further explored. In in vitro experiments, the RT-PCR results showed the upregulated TEAD2/4 in OSC tissues and cells (A2780 and TOV112D). Moreover, decreased expression of TEAD2 could induce the ferroptosis through increasing the ROS accumulation.

Conclusion

Thus, TEAD family correlated with the diagnosis, prognosis and immune infiltration in OSC. These results could provide comprehensive understanding of TEAD family in the diagnosis and prognosis of OSC patients.

Genome edited B cells: a new frontier in immune cell therapies

Cell therapies based on reprogrammed adaptive immune cells have great potential as "living drugs." As first demonstrated clinically for engineered chimeric antigen receptor (CAR) T cells, the ability of such cells to undergo clonal expansion in response to an antigen promotes both self-renewal and self-regulation in vivo. B cells also have the potential to be developed as immune cell therapies, but engineering their specificity and functionality is more challenging than for T cells. In part, this is due to the complexity of the immunoglobulin (Ig) locus, as well as the requirement for regulated expression of both cell surface B cell receptor and secreted antibody isoforms, in order to fully recapitulate the features of natural antibody production. Recent advances in genome editing are now allowing reprogramming of B cells by site-specific engineering of the Ig locus with preformed antibodies. In this review, we discuss the potential of engineered B cells as a cell therapy, the challenges involved in editing the Ig locus and the advances that are making this possible, and envision future directions for this emerging field of immune cell engineering.