Mechanistic study of TIMM44 mediating gastric carcinogenesis via the Gαi1-PI3K-AKT-mTOR signaling pathway

Sep 22, 2026

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Hyperglycemic conditions increase TIMM44, a mitochondrial inner membrane protein, but its function in gastric cancer remains unclear. Western blot and qRT-PCR assessed TIMM44 protein and mRNA levels, while flow cytometry evaluated cell-cycle progression. Cell viability, migration, invasion, and proliferation were tested using CCK-8, colony formation, wound healing, Transwell, and EdU assays; apoptosis was measured by TUNEL. Immunohistochemistry compared TIMM44 in gastric cancer versus adjacent tissues. TIMM44 was highly expressed in tumor samples; overexpression promoted malignancy, whereas depletion inhibited it, accompanied by increased Gαi1 and AKT phosphorylation.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages14

Reading Time35 min

AccessFree to download

Background

Gastric cancer burden and biomarker need

Known roles of Gαi1/3 signaling

Rationale and related evidence

TIMM44 in hyperglycemia and mitochondria-related tumor biology

Prior links to prognosis and signaling regulation

Methods and experimental approach

Expression assays: western blot and qRT-PCR

Cell phenotyping: flow cytometry, CCK-8, colony formation, wound healing, Transwell, EdU

Apoptosis and tissue comparison: TUNEL and immunohistochemistry

[www. nature.com/scientificreports](www. nature.com/scientificreports) OPEN Mechanistic study of TIMM44 mediating gastric carcinogenesis via the Gαi1-PI3K-AKT-mTOR signaling pathway Ting Chen1,6, Rong Xu2,6, Xiaojing Shi1,6, Dongliang Yang3, Yi Du4, Yu Song1􀀍, Yan Lv5􀀍 & Yanan Chen1􀀍 Hyperglycemic conditions up-regulate TIMM44, an inner mitochondrial membrane protein. Its expression is related to many cancers, yet its role in gastric cancer (GC) remains unproven. To study this, we used western blot and qRT-PCR to measure protein and mRNA levels. Flow cytometry analyzed cell cycle progression. CCK − 8, colony formation, wound healing, Transwell, and EdU assays evaluated cell viability, migratory and invasion abilities. TUNEL-based method detected apoptosis, and immunohistochemical assay compared TIMM44 expression inGC and adjacent non-cancerous tissues. The results showed TIMM44 was highly expressed in GC tissues. Over-expressing TIMM44 promoted AGS and HGC27 cells’ viability, proliferation, invasion, and migration, while its depletion inhibited these. Forced TIMM44 expression increased Gαi1 andAkt phosphorylation. In conclusion, TIMM44 is crucial in the Gαi1-PI3K-AKT-mTOR pathway, enhancing GC cells’ malignancy and potentially threatening patient survival. Keywords Gastric cancer, TIMM44, Gαi1, AKT-mTOR pathway, Molecularly targeted therapy Gastric cancer (GC) is among the most frequently encountered malignancies on a global scale. Alarmingly, it stands as the third leading cause of mortality among all cancer types, accounting for an approximate 9% mortality rate1,2. Approximately 40% of the world’s annual 1.2 million new cases of GC are reported in China3. A significant majority of GC cases are typically diagnosed at an advanced stage, constituting 80–85% of all instances, and the 5-year survival rate on a broader scale remains below 50% in China4. Several contributing factors are associated with the development of GC, including Helicobacter pylori infection, dietary habits, tobacco use, alcohol consumption, obesity, gender disparities, genetic mutations, hereditary predisposition, and familial medical history5. Treatment of GC has improved significantly because of advances in diagnostic methods, immunotherapy, and molecularly targeted therapy. Despite improvements in GC treatment, the 5-year survival rate remains unsatisfactory. Early diagnosis, therapy, and prognosis of GC rely on research and identification of biomarkers6,7. Previous research by our group has established that G protein inhibitory α subunits 1 and 3 (Gαi1/3 proteins) are critical components of multiple signalling cascades. Gαi1/3 proteins interact with receptors such as tyrosine kinases (RTKs) to mediate downstream signal (PI3K-Akt-mTOR and ERK-MAPK) transduction, when stimulated by multiple cells and growth factors8. The expression of Gαi1/3 displayed an elevation in glioma tissues in contrast to normal brain tissues. In the inner mitochondrial membrane, YME1L (YME1 Like 1 ATPase) on the inner mitochondrial membrane leads to an enhancement in the proliferative capacity of glioma cell by facilitating the Gαi1 up-regulation, consequently triggering downstream activation of Akt activation9. Gαi1/3 has been found to be the key protein for Netrin-1, which induces downstream signal transduction and retinal angiogenesis10. Our earlier investigation illuminated the up-regulation of Gαi1 in GC, establishing a link with lowered overall survival rates. Additionally, we identified that microRNA-200a (miR-200a) directly restricts the expression of Gαi1, consequently instigating anti-GC cell activities11. 1Department of Oncology, Zhangjiagang Hospital Affiliated to Soochow University, Suzhou, China. 2Department of Pathology, Zhangjiagang Hospital Affiliated to Soochow University, Suzhou, China. 3Department of Urinary Surgery, Zhangjiagang Hospital Affiliated to Soochow University, Suzhou, China. 4Department of Gynecology, Zhangjiagang Hospital Affiliated

FAQs

What is the main purpose of the study on TIMM44 in gastric cancer?

To determine how TIMM44 contributes to gastric carcinogenesis and whether it acts through the Gαi1-PI3K-AKT-mTOR signaling pathway under hyperglycemic conditions.

How did the researchers measure TIMM44 expression?

They used western blot and qRT-PCR to quantify TIMM44 protein and mRNA levels, and immunohistochemistry to compare TIMM44 in gastric cancer tissues versus adjacent non-cancerous tissues.

What effects did TIMM44 overexpression and depletion have on gastric cancer cells?

Overexpression increased cell viability, proliferation, invasion, and migration, while TIMM44 depletion inhibited these malignant behaviors.

Sep 22, 2026

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