Changes in mucosa­associated lymphoid tissue 1 predicts therapeutic response and survival in patients with advanced melanoma receiving programmed cell death­1 inhibitor monotherapy.

Advanced melanoma is an aggressive and dangerous form of skin cancer, and programmed cell death-1 (PD-1) inhibitors are recommended treatment options for patients with advanced melanoma. Mucosa-associated lymphoid tissue 1 (MALT1) impairs CD8+ T-cell activation to induce immune escape, leading to a reduction in the antitumor effect of PD-1 inhibitors. The present study aimed to assess the prognostic implication of MALT1 in patients with advanced melanoma receiving PD-1 inhibitor monotherapy. Blood MALT1 levels were assessed using reverse transcription-quantitative PCR in 20 healthy controls (HCs) after enrollment and in 49 patients with advanced melanoma before (T0), as well as 2 months (T1) and 4 months after (T2) PD-1 inhibitor monotherapy. The maximum level of MALT1 in HCs (3.100) was used as the cut-off in patients with advanced melanoma. MALT1 levels at T0 were significantly increased in patients with advanced melanoma compared with in HCs (P<0.001). In patients with advanced melanoma, MALT1 was significantly decreased from T0 to T2 (P<0.001). Objective response rate (ORR) and disease control rate (DCR) were 28.6 and 59.2%, respectively. MALT1 levels at T1 were significantly negatively associated with overall therapeutic response (P=0.001), ORR (P=0.009) and DCR (P=0.004). MALT1 levels at T2 were significantly inversely associated with overall therapeutic response (P=0.021) and ORR (P=0.036). Moreover, MALT1 levels >3.100 at T0 (P=0.027) and T1 (P=0.045) were significantly associated with shorter progression-free survival (PFS), and MALT1 levels >3.100 at T1 were significantly associated with a poor overall survival (OS; P=0.022). Multivariate Cox regression analysis demonstrated that MALT1 levels at T0 (>3.100 vs. ≤3.100) were significantly associated with a poor PFS [hazard ratio (HR)=2.248; P=0.037], and MALT1 levels at T1 (>3.100 vs. ≤3.100) were significantly associated with a poor OS (HR=4.332; P=0.007). In conclusion, MALT1 levels are reduced following PD-1 treatment, and a high MALT1 level is associated with a poor therapeutic response and shorter survival in patients with advanced melanoma receiving PD-1 inhibitor monotherapy.

Knockdown of LRP5 Promotes Proliferation and Invasion of Tongue Squamous Cell Carcinoma through Compensatory Activation of Akt Signaling.

The role of LRP5, a critical receptor in the Wnt signaling pathway, remains unexplored in tongue squamous cell carcinoma (TSCC). This study investigates the impact of LRP5 knockdown on the biological behaviors of TSCC cell lines both in vitro and in vivo. Our findings indicate that LRP5 knockdown significantly enhances cell proliferation, migration, and invasion in CAL27 and SCC25 cell lines. RNA-seq analysis reveals compensatory activation of the Akt pathway, with 119 genes significantly upregulated post-LRP5 knockdown. Elevated MMP1 expression suggests its potential involvement in TSCC progression. Western blot analysis demonstrates increased Akt phosphorylation, upregulated proliferation-related PCNA, and downregulated apoptosis-related caspase-3 after LRP5 knockdown. Down-regulation of E-cadherin and ß-Catenin, proteins associated with cell adhesion and invasion, further elucidates the molecular mechanism underlying increased cell migration and invasion. Our study concludes that compensatory Akt pathway activation is essential for the LRP5 knockdown-induced migration and proliferation of CAL27 and SCC25 cells. These results highlight LRP5 as a potential therapeutic target for TSCC. Simultaneous inhibition of Wnt and Akt signaling emerges as a promising approach for TSCC treatment.