MYCBP2 expression correlated with inflammatory cell infiltration and prognosis immunotherapy in thyroid cancer patients

A Molecular Signature of the Ubiquitin-Proteasome System for Forecasting Prognosis in Thyroid Carcinoma Patients

Background

The ubiquitin-proteasome system (UPS) is vital for protein quality control and its dysregulation is linked to diseases, including cancer. Targeting the UPS is becoming a promising approach in cancer therapy. However, the role of UPS modulation in thyroid carcinoma (THCA) remains to be fully elucidated.

Methods

Initially, we utilized data from The Cancer Genome Atlas (TCGA) database to employ weighted gene co-expression network analysis (WGCNA) with LASSO regression to develop a prognostic model for core UPS genes implicated in THCA. Subsequently, we stratified the THCA training set into two distinct subtypes based on ubiquitin-proteasome system prognostic model score (UPS-PMS) characteristics. Key genes within the model were then subjected to functional analysis, immunotherapy evaluation, and drug sensitivity studies.

Results

We delineated a prognostic model of the UPS comprising six genes, which we subsequently demonstrated was capable of forecasting patient prognosis. Moreover, our findings indicated a substantial correlation between UPS-PMS and immune microenvironmental factors, notably a negative correlation with myeloid immune cells and a potential influence on the Th1 to Th2 cells ratio. Especially, we observed a significant association between high UPS-PMS and an immunosuppressive microenvironment. Then, we elucidated the biological distinctions among various THCA sample subtypes, highlighting that the cluster_1 subtype is associated with an unfavorable prognosis. Of note, KCNA1 was identified as a pivotal prognostic gene within the UPS-PMS framework. We constructed a three-tiered regulatory network centered on KCNA1-related competing endogenous RNA (ceRNA). Furthermore, our results suggested that KCNA1 has potential as a target for immunotherapeutic strategies. Concurrently, drug sensitivity analyses demonstrated that high KCNA1 expression promoted gemcitabine resistance in patients, while KCNA1 knockdown increased sensitivity to gemcitabine.

Conclusion

In conclusion, we developed a novel UPS-based prognostic model for THCA, identified key gene KCNA1, and assessed immunotherapy and drug sensitivity, revealing new therapeutic targets.

Cell of origin alters myeloid-mediated immunosuppression in lung adenocarcinoma

Solid carcinomas are often highly heterogenous cancers, arising from multiple epithelial cells of origin. Yet, how the cell of origin influences the response of the tumor microenvironment is poorly understood. Lung adenocarcinoma (LUAD) arises in the distal alveolar epithelium which is populated primarily by alveolar epithelial type I (AT1) and type II (AT2) cells. It has been previously reported that Gramd2 + AT1 cells can give rise to a histologically-defined LUAD that is distinct in pathology and transcriptomic identity from that arising from Sftpc + AT2 cells1,2. To determine how cells of origin influence the tumor immune microenvironment (TIME) landscape, we comprehensively characterized transcriptomic, molecular, and cellular states within the TIME of Gramd2 + AT1 and Sftpc + AT2-derived LUAD using KRASG12D oncogenic driver mouse models. Myeloid cells within the Gramd2 + AT1-derived LUAD TIME were increased, specifically, immunoreactive monocytes and tumor associated macrophages (TAMs). In contrast, the Sftpc + AT2 LUAD TIME was enriched for Arginase-1+ myeloid derived suppressor cells (MDSC) and TAMs expressing profiles suggestive of immunosuppressive function. Validation of immune infiltration was performed using flow cytometry, and intercellular interaction analysis between the cells of origin and major myeloid cell populations indicated that cell-type specific markers SFTPD in AT2 cells and CAV1 in AT1 cells mediated unique interactions with myeloid cells of the differential immunosuppressive states within each cell of origin mouse model. Taken together, Gramd2 + AT1-derived LUAD presents with an anti-tumor, immunoreactive TIME, while the TIME of Sftpc + AT2-derived LUAD has hallmarks of immunosuppression. This study suggests that LUAD cell of origin influences the composition and suppression status of the TIME landscape and may hold critical implications for patient response to immunotherapy.

Role of the ubiquitin-proteasome system on macrophages in the tumor microenvironment

Tumor-associated macrophages (TAMs) are key components of the tumor microenvironment, and their different polarization states play multiple roles in tumors by secreting cytokines, chemokines, and so on, which are closely related to tumor development. In addition, the enrichment of TAMs is often associated with poor prognosis of tumors. Thus, targeting TAMs is a potential tumor treatment strategy, in which therapeutic approaches such as reducing TAMs numbers, remodeling TAMs phenotypes, and altering their functions are being extensively investigated. Meanwhile, the ubiquitin-proteasome system (UPS), an important mechanism of protein hydrolysis in eukaryotic cells, participates in cellular processes by regulating the activity and stability of key proteins. Interestingly, UPS plays a dual role in the process of tumor development, and its role in TAMs deserve to be investigated in depth. This review builds on this foundation to further explore the multiple roles of UPS on TAMs and identifies a promising approach to treat tumors by targeting TAMs with UPS.