Silencing of TMSG1 enhances metastasis capacity by targeting V-ATPase in breast cancer

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Tumor metastasis suppressor 1 (TMSG1) is a novel gene linked to breast cancer metastasis and drug resistance.
• The precise molecular mechanisms underlying TMSG1's role in breast cancer progression remain largely unelucidated.

Purpose of the Study:

• To investigate the impact of TMSG1 gene silencing on the invasive capabilities of the human breast carcinoma cell line MCF-7.
• To elucidate the molecular mechanisms involving extracellular pH that mediate TMSG1's effect on breast cancer metastasis.

Main Methods:

• Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot analysis were employed to assess TMSG1 mRNA and protein levels.
• Small interfering RNA (siRNA) was used to silence TMSG1 expression in MCF-7 cells.
• Cell migration and invasion assays were performed, alongside measurements of vacuolar ATPase (V-ATPase) and matrix metalloproteinase-2 (MMP-2) activity.

Main Results:

• TMSG1 silencing via siRNA significantly reduced TMSG1 mRNA and protein expression in MCF-7 cells.
• Silencing TMSG1 markedly increased cell migration and invasion capabilities.
• V-ATPase and MMP-2 activity were significantly elevated in TMSG1-silenced cells.
• An acidic extracellular environment was found to enhance MMP-2 activity, cell migration, and invasion.

Conclusions:

• TMSG1 silencing promotes breast cancer cell metastasis.
• The mechanism involves increased V-ATPase activity, leading to decreased extracellular pH.
• This acidic environment facilitates MMP-2 activation, thereby enhancing the metastatic potential of breast cancer cells.