PITPNC1 Suppress CD8+ T cell immune function and promote radioresistance in rectal cancer by modulating FASN/CD155

A brief history of phosphatidylinositol transfer proteins: from the backwaters of cell biology to prime time in lipid signaling

How lipids are sorted between intracellular compartments and what mechanisms support inter-organellar lipid transport define questions that have enjoyed long-standing interest in the cell biology community. Despite tantalizing evidence to the effect that lipids can move between organelles independently of standard modes of vesicular membrane trafficking through the secretory pathway, biochemical dissection of these non-vesicular pathways was initially fraught with experimental challenges. Many of the obstacles have now been overcome and, following initial breakthroughs, the last two decades have witnessed a renaissance in the field of lipid trafficking. Indeed, lipid trafficking and mobilization are now significant components of any discussion regarding secretory vesicle trafficking, organelle biogenesis, agonist-stimulated lipid signaling, and inter-compartmental communication pathways that involve every organelle in the eukaryotic cell. In accord with the theme of this special issue, we focus on the topic of soluble lipid transfer proteins that interface with the metabolism of phosphatidylinositol (PtdIns) and its phosphorylated derivatives - the phosphoinositides. Although phosphoinositides are quantitatively minor lipids in cells, these molecules represent the chemical codes for a major pathway of intracellular signaling in all eukaryotic cells. It is now clear that soluble PtdIns transfer proteins (PITPs) are physiologically critical regulators of specific pathways of phosphoinositide - particularly PtdIns-4-phosphate - signaling. The 'where' PITPs determine the biological outcomes of phosphoinositide signaling, and the 'how' by which PITPs do so, represent increasingly active areas of research in contemporary cell biology. It is these issues we explore from a historical perspective with a focus on the Sec14-like PITPs.

Propensity score analysis of high-dose rate brachytherapy, immune checkpoint inhibitors, and docetaxel in second-line advanced NSCLC treatment

This study evaluated the efficacy and safety of combining high-dose-rate brachytherapy, immune checkpoint inhibitors, and docetaxel as second-line treatment for advanced NSCLC, given the poor prognosis after first-line therapy. We conducted a single-center, retrospective, propensity score-matched study comparing HDR brachytherapy plus ICIs and docetaxel (study group) versus ICIs plus docetaxel (control group) in patients with advanced NSCLC who progressed after prior treatment without known driver gene mutations or uninvestigated mutation status. After propensity score matching, 21 patients were included in each group. The study group had a higher ORR (42.9% vs. 28.6%). Median OS was 18.6 months for the study group and 12.8 months for the control group (HR 0.45, 95% CI 0.20-0.85, P = 0.042). Median PFS was 8.6 vs. 5.6 months (HR   0.29, 95% CI 0.15-0.55, P < 0.001). The DCR was higher in the study group (71.4% vs. 61.9%). Treatment-related AEs were manageable, with no significant increase in grade 3/4 toxicities in the study group. Results suggest that combining high-dose rate brachytherapy, immune checkpoint inhibitors, and docetaxel may improve survival and response rates in advanced NSCLC after first-line therapy. Prospective randomized trials are necessary to confirm these findings and validate the strategy's effectiveness.

Troxerutin suppresses the stemness of osteosarcoma via the CD155/SRC/β-catenin signaling axis

BACKGROUND

Osteosarcoma is the most prevalent primary malignant bone tumor affecting pediatric and adolescent individuals. However, despite the passage of three decades, there has been no notable enhancement in the overall survival rate of patients with osteosarcoma. In recent years, CD155 has been reported to exhibit abnormal amplification in a range of tumors, yet the precise underlying mechanism remains elusive. The objective of this study is to investigate the role of CD155 in osteosarcoma, and to identify drugs that specifically target this molecule, thereby offering a novel direction for the treatment of osteosarcoma.

METHODS

The prognosis of patients with osteosarcoma with high and low expression of CD155 was verified by immunohistochemistry. CCK-8 and colony formation assays were used to detect cell proliferation and drug resistance. Transwell experiments were used to detect cell migration and invasion. The sphere formation experiment was used to evaluate the stemness of tumor cells. Additionally, in vivo animal models were utilized to assess the functional role of CD155 in a biological context. RNA-seq and co-immunoprecipitation methods were used to search for downstream target molecules and signaling pathways of CD155. Finally, virtual screening was used to find drugs targeting CD155.

RESULTS

In this study, we have established the significant amplification of CD155 in osteosarcoma. Utilizing a comprehensive array of experimental methods, including CCK-8 assay, colony formation assay, Transwell assay, and in vivo animal models, we unequivocally demonstrate that CD155 significantly potentiates the malignancy of osteosarcoma both in vitro and in vivo. Additionally, our findings reveal that CD155 promotes osteosarcoma stemness by modulating the Wnt/β-catenin signaling pathway. Advanced molecular techniques, such as RNA sequencing and co-immunoprecipitation, have been instrumental in elucidating the mechanism of CD155 in activating the Wnt/β-catenin pathway via the SRC/AKT/GSK3β signaling axis, thereby enhancing the stem-cell-like properties of osteosarcoma cells. To explore targeted therapeutic options, we conducted virtual screening and identified troxerutin as a promising CD155 inhibitor.

CONCLUSIONS

Our findings reveal that troxerutin effectively inhibits CD155, attenuates the SRC/AKT/GSK3β signaling cascade, diminishes the nuclear localization of β-catenin, and consequently mitigates osteosarcoma stemness. These discoveries position troxerutin as a promising candidate for targeted osteosarcoma therapy.

Expanding functions of the phosphatidylinositol/phosphatidate lipid transporter, PITPNC1 in physiology and in pathology

PITPNC1 was the last of the PITPs to be identified and has been characterized as a binding protein for phosphatidylinositol and phosphatidate. In mammals, PITPNC1 is expressed as two splice variants whilst in zebrafish is expressed from two separate genes. The two splice variants have different expression profiles with the long splice variant having a prominent role in the brain. Several physiological functions have been identified including neuronal and metabolic functions. PITPNC1 also plays a significant role in cancer and has been identified as a risk factor in type 2 diabetes. Here, we review our current understanding of PITPNC1 in cell physiology and pathology.

Mammalian START-like phosphatidylinositol transfer proteins - Physiological perspectives and roles in cancer biology

PtdIns and its phosphorylated derivatives, the phosphoinositides, are the biochemical components of a major pathway of intracellular signaling in all eukaryotic cells. These lipids are few in terms of cohort of unique positional isomers, and are quantitatively minor species of the bulk cellular lipidome. Nevertheless, phosphoinositides regulate an impressively diverse set of biological processes. It is from that perspective that perturbations in phosphoinositide-dependent signaling pathways are increasingly being recognized as causal foundations of many human diseases - including cancer. Although phosphatidylinositol transfer proteins (PITPs) are not enzymes, these proteins are physiologically significant regulators of phosphoinositide signaling. As such, PITPs are conserved throughout the eukaryotic kingdom. Their biological importance notwithstanding, PITPs remain understudied. Herein, we review current information regarding PITP biology primarily focusing on how derangements in PITP function disrupt key signaling/developmental pathways and are associated with a growing list of pathologies in mammals.

Identification of fatty acid metabolism signature genes in patients with pulmonary arterial hypertension using WGCNA and machine learning

OBJECTIVE

To investigate the signature genes of fatty acid metabolism and their association with immune cells in pulmonary arterial hypertension (PAH).

METHODS

Fatty acid metabolism-related genes were obtained from the GeneCards database. In this retrospective study, a PAH-related dataset was downloaded from the Gene Expression Omnibus database and analyzed to identify differentially expressed genes (DEGs). Weighted gene co-expression network analysis (WGCNA) and machine learning algorithms, including least absolute shrinkage and selection operator (LASSO) and random forest, were used to identify the signature genes. Diagnostic efficiency was assessed by receiver operating characteristic (ROC) curve analysis and a nomogram. Immune cell infiltration was subsequently classified using CIBERSORT.

RESULTS

In total, 817 DEGs were screened from the GSE33463 dataset. The data were clustered into six modules via WGCNA, and the MEdarkred module was significantly related to PAH. The LASSO and random forest algorithms identified five signature genes: ARV1, KCNJ2, PEX11B, PITPNC1, and SCO1. The areas under the ROC curves of these signature genes were 0.917, 0.934, 0.947, 0.963, and 0.940, respectively. CIBERSORT suggested these signature genes may participate in immune cell infiltration.

CONCLUSIONS

ARV1, KCNJ2, PEX11B, PITPNC1, and SCO1 show remarkable diagnostic performance in PAH and are involved in immune cell infiltration.

Caffeic acid phenethyl ester promotes oxaliplatin sensitization in colon cancer by inhibiting autophagy

Colon cancer ranks as the third most prevalent form of cancer globally, with chemotherapy remaining the primary treatment modality. To mitigate drug resistance and minimize adverse effects associated with chemotherapy, selection of appropriate adjuvants assumes paramount importance. Caffeic acid phenethyl ester (CAPE), a naturally occurring compound derived from propolis, exhibits a diverse array of biological activities. We observed that the addition of CAPE significantly augmented the drug sensitivity of colon cancer cells to oxaliplatin. In SW480 and HCT116 cells, oxaliplatin combined with 10 µM CAPE reduced the IC50 of oxaliplatin from 14.24 ± 1.03 and 84.16 ± 3.02 µM to 2.11 ± 0.15 and 3.92 ± 0.17 µM, respectively. We then used proteomics to detect differentially expressed proteins in CAPE-treated SW480 cells and found that the main proteins showing changes in expression after CAPE treatment were p62 (SQSTM1) and LC3B (MAP1LC3B). Gene ontology analysis revealed that CAPE exerted antitumor and chemotherapy-sensitization effects through the autophagy pathway. We subsequently verified the differentially expressed proteins using immunoblotting. Simultaneously, the autophagy inhibitor bafilomycin A1 and the mCherry-EGFP-LC3 reporter gene were used as controls to detect the effect of CAPE on autophagy levels. Collectively, the results indicate that CAPE may exert antitumor and chemotherapy-sensitizing effects by inhibiting autophagy, offering novel insights for the development of potential chemosensitizing agents.

Identification of a 9-gene signature to enhance biochemical recurrence prediction in primary prostate cancer: A benchmarking study using ten machine learning methods and twelve patient cohorts

Prostate cancer (PCa) is a prevalent malignancy among men worldwide, and biochemical recurrence (BCR) after radical prostatectomy (RP) is a critical turning point commonly used to guide the development of treatment strategies for primary PCa. However, the clinical parameters currently in use are inadequate for precise risk stratification and informing treatment choice. To address this issue, we conducted a study that collected transcriptomic data and clinical information from 1662 primary PCa patients across 12 multicenter cohorts globally. We leveraged 101 algorithm combinations that consisted of 10 machine learning methods to develop and validate a 9-gene signature, named BCR SCR, for predicting the risk of BCR after RP. Our results demonstrated that BCR SCR generally outperformed 102 published prognostic signatures. We further established the clinical significance of these nine genes in PCa progression at the protein level through immunohistochemistry on Tissue Microarray (TMA). Moreover, our data showed that patients with higher BCR SCR tended to have higher rates of BCR and distant metastasis after radical radiotherapy. Through drug target prediction analysis, we identified nine potential therapeutic agents for patients with high BCR SCR. In conclusion, the newly developed BCR SCR has significant translational potential in accurately stratifying the risk of patients who undergo RP, monitoring treatment courses, and developing new therapies for the disease.