# GPR168 functions as a tumor suppressor in mouse melanoma by restraining Akt signaling pathway

## TL;DR

This study shows that GPR168 acts as a tumor suppressor in mouse melanoma by inhibiting the Akt signaling pathway, reducing cancer cell growth and spread.

## Contribution

The study identifies GPR168 as a novel tumor suppressor in melanoma through its regulation of the Akt signaling pathway.

## Key findings

- GPR168 overexpression inhibits B16-F10 cell proliferation, migration, and tumor growth in xenograft models.
- GPR168 suppresses melanoma progression by downregulating p-Akt, p-GSK-3β, β-catenin, Myc, CyclinD1, and CDK4.
- Blocking GPR168 with an antibody restores cell proliferation and migration, confirming its tumor-suppressive role.

## Abstract

Malignant melanoma (MM) is a malignant tumor associated with high mortality rates and propensity for metastasis. Despite advancement in treatment, the incidence of MM continue to rise globally. GPR168, also known as MrgprF, is a MAS related GPR family member. The low expression of GPR168 has also been reported in many malignant tumors including MM. In the study, the statistical analysis from The Cancer Genome Atlas (TCGA) revealed a significant down regulation of GPR168 in melanoma compared to normal melanocytes, underscoring its importance in MM. The aim of the present study is to investigate the affect of GPR168 overexpression and elucidate its molecular mechanisms in MM cells. In addition, we used mouse melanoma B16-F10 cell line and xenograph tumor model to explore the function of GPR168 in melanoma. Our findings demonstrate that GPR168 overexpression could inhibit B16-F10 cell proliferation, migration, and xenografts tumor growth. Further, mechanistic studies revealed that GPR168 affected B16-F10 progress through Akt signal pathway with the decreased expression of p-Akt, p-GSK-3β, β-catenin, Myc, CyclinD1 and CDK4. In order to validate these findings, a rescue experiment was formulated employing GPR168 polyclonal antibody (Anti-GPR168 pAbs) to block GPR168 functionality. The addition of Anti-GPR168 pAbs into the culture medium restored both cell proliferation and migration. In conclusion, the overexpression of GPR168 in mouse melanoma B16-F10 cells suppressed proliferation and migration through the Akt signaling pathway. These findings collectively propose GPR168 as a promising novel tumor suppressor in MM, suggesting its potential as a therapeutic target in future interventions.