Metabolic Health Together with a Lipid Genetic Risk Score Predicts Survival of Small Cell Lung Cancer Patients

Levels of serum lipids predict responses to PD-L1 inhibitors as first-line treatment in small cell lung cancer: an observational study

BACKGROUND

Immunotherapy provides new hope to individuals with small cell lung cancer (SCLC). Predicting biomarkers for clinical effects is crucial for SCLC patients receiving programed death-ligand 1 (PD-L1) inhibitor treatment.

AIM

The aim of this study was to clarify the value of serum lipids as predictors of immune related adverse events (irAEs) and the anti-tumour effects in SCLC patients who received PD-L1 inhibitors as first-line treatment.

METHOD

This study included patients with SCLC who received at least one cycle of PD-L1inhibitors at Shanghai Pulmonary Hospital from August 2020 to December 2023. We collected the clinical data of the SCLC patients, including basic information and serum lipid levels, before immunotherapy.

RESULTS

The irAEs rate was 16.1% of 124 enrolled patients. In multivariate analysis, the triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C) ratio was an independent predictor of irAEs (p = 0.045). Tumour response analysis indicated that the objective response rate (ORR) was 43.4% and the disease control rate (DCR) was 79.5%. Seventy-seven patients experienced any progression-free survival (PFS) event. The median PFS was longer in the HDL-C-high group (10.03 months) than in the HDL-C-low group (6.67 months) (p = 0.043). In Cox regression analysis, the serum HDL-C level was an independent predictor of PFS (p = 0.002). For patients of the high TG/HDL-C ratio, the ORR significantly differed between patients who suffered from any irAEs and those who did not (p = 0.0139).

CONCLUSION

This study found that serum lipid levels might predict the responses to anti-PD-L1 as first-line treatment for SCLC.

Clinical features and lipid metabolism genes as potential biomarkers in advanced lung cancer

BACKGROUND

Lung cancer is one of the most lethal tumors with a poor survival rate even in those patients receiving new therapies. Metabolism is considered one of the hallmarks in carcinogenesis and lipid metabolism is emerging as a significant contributor to tumor metabolic reprogramming. We previously described a profile of some lipid metabolism related genes with potential prognostic value in advanced lung cancer.

AIM

To analyze clinical and pathological characteristics related to a specific metabolic lipid genomic signature from patients with advanced lung cancer and to define differential outcome.

METHODS

Ninety samples from NSCLC (non-small cell lung cancer) and 61 from SCLC (small cell lung cancer) patients were obtained. We performed a survival analysis based on lipid metabolic genes expression and clinical characteristics. The primary end point of the study was the correlation between gene expression, clinical characteristics and survival.

RESULTS

Clinical variables associated with overall survival (OS) in NSCLC patients were clinical stage, adenocarcinoma histology, Eastern Cooperative Oncology Group (ECOG), number and site of metastasis, plasma albumin levels and first-line treatment with platinum. As for SCLC patients, clinical variables that impacted OS were ECOG, number of metastasis locations, second-line treatment administration and Diabetes Mellitus (DM). None of them was associated with gene expression, indicating that alterations in lipid metabolism are independent molecular variables providing complementary information of lung cancer patient outcome.

CONCLUSIONS

Specific clinical features as well as the expression of lipid metabolism-related genes might be potential biomarkers with differential outcomes.

The Deubiquitinase USP13 Maintains Cancer Cell Stemness by Promoting FASN Stability in Small Cell Lung Cancer

USP13 is significantly amplified in over 20% of lung cancer patients and critical for tumor progression. However, the functional role of USP13 in small cell lung cancer (SCLC) remains largely unclear. In this study, we found that the deubiquitinase USP13 is highly expressed in SCLC tumor samples and positively associated with poor prognosis in multiple cohorts. In vitro and in vivo depletion of USP13 inhibited SCLC cancer stem cells (CSCs) properties and tumorigenesis, and this inhibitory effect was rescued by reconstituted expression of wide type (WT) USP13 but not the enzyme-inactive USP13 mutant. Mechanistically, USP13 interacts with fatty acid synthase (FASN) and enhances FASN protein stability. FASN downregulation suppresses USP13-enhanced cell renewal regulator expression, sphere formation ability, and de novo fatty acids biogenesis. Accordingly, we found FASN expression is upregulated in surgical resected SCLC specimens, positively correlated with USP13, and associated with poor prognosis of SCLC patients. More importantly, the small molecule inhibitor of FASN, TVB-2640, significantly inhibits lipogenic phenotype and attenuates self-renewal ability, chemotherapy resistance and USP13-mediated tumorigenesis in SCLC. Thus, our study highlights a critical role of the USP13-FASN-lipogenesis axis in SCLC cancer stemness maintenance and tumor growth, and reveals a potential combination therapy for SCLC patients.