Pro-tumorigenic activity of PYCR1 in gastric cancer through regulating the PI3K/AKT signaling

Background

The primary objective of this investigation was to assess the impact of pyrroline-5-carboxylate reductase 1 (PYCR1) on the progression of gastric cancer (GC), specifically focusing on tumor growth and metastatic potential.

Methods

Surgical specimens from patients with different stages of GC were assayed for PYCR1 expression using immunohistochemistry. PYCR1 expression was manipulated by depletion or overexpression approaches in GC cells, and these cells were applied to explore the functional roles of PYCR1. Expression of apoptosis- and metastasis-related markers was quantified through quantitative real-time PCR and Western blot.

Results

Higher PYCR1 expression was ascertained in surgical specimens from patients with GC as compared to noncancerous adjacent tissues. Additionally, PYCR1 overexpression in GC tissues was linked to adverse clinical outcomes. The depletion of PYCR1 in GC cells resulted in a pronounced reduction in proliferation, the induction of apoptosis, and the attenuation of invasion and metastasis. Conversely, its ectopic expression notably augmented proliferation, restricted apoptosis, and stimulated invasion and metastasis. In addition, the knockdown of PYCR1 resulted in a significant elevation in the activation of caspase 3, a key protein involved in apoptosis. This depletion also led to a decrease in the activation or expression of proteins associated with metastasis, such as phosphorylated (p)-phosphatidylinositol 3-kinase (PI3K), p-AKT serine/threonine kinase (AKT), and snail family transcriptional repressor 1 (Snail). Additionally, it resulted in an upregulation of E-cadherin expression. Conversely, the overexpression of PYCR1 notably increased the levels of p-PI3K, p-AKT, and Snail, while simultaneously reducing E-cadherin expression.

Conclusion

PYCR1, by activating PI3K/AKT signaling, assumes a crucial role in governing malignant characteristics of GC cells, including proliferation, apoptosis, and metastasis. These findings underscore the promising potential of PYCR1 as a diagnostic biomarker and a target for tailored therapeutic interventions in patients with GC.

Deciphering the effects of PYCR1 on cell function and its associated mechanism in hepatocellular carcinoma

Overexpression of pyrroline-5-carboxylate reductase 1 (PYCR1) has been associated with the development of certain cancers; however, no studies have specifically examined the role of PYCR1 in hepatocellular carcinoma (HCC). Based on The Cancer Genome Atlas expression array and meta-analysis conducted using the Gene Expression Omnibus database, we determined that PYCR1 was upregulated in HCC compared to adjacent nontumor tissues (P < 0.05). These data were verified using quantitative real-time polymerase chain reaction, western blotting, and immunohistochemistry analysis. Additionally, patients with low PYCR1 expression showed a higher overall survival rate than patients with high PYCR1 expression. Furthermore, PYCR1 overexpression was associated with the female sex, higher levels of alpha-fetoprotein, advanced clinical stages (III and IV), and a younger age (< 45 years old). Silencing of PYCR1 inhibited cell proliferation, invasive migration, epithelial-mesenchymal transition, and metastatic properties in HCC in vitro and in vivo. Using RNA sequencing and bioinformatics tools for data-dependent network analysis, we found binary relationships among PYCR1 and its interacting proteins in defined pathway modules. These findings indicated that PYCR1 played a multifunctional role in coordinating a variety of biological pathways involved in cell communication, cell proliferation and growth, cell migration, a mitogen-activated protein kinase cascade, ion binding, etc. The structural characteristics of key pathway components and PYCR1-interacting proteins were evaluated by molecular docking, and hotspot analysis showed that better affinities between PYCR1 and its interacting molecules were associated with the presence of arginine in the binding site. Finally, a candidate regulatory microRNA, miR-2355-5p, for PYCR1 mRNA was discovered in HCC. Overall, our study suggests that PYCR1 plays a vital role in HCC pathogenesis and may potentially serve as a molecular target for HCC treatment.