Comparative Secretome Analyses Using a Hollow Fiber Culture System with Label-Free Quantitative Proteomics Indicates the Influence of PARK7 on Cell Proliferation and Migration/Invasion in Lung Adenocarcinoma

As the leading cause of cancer death worldwide, lung
cancer lacks effective diagnosis tools and treatments to prevent its
metastasis. Fortunately, secretome has clinical usages as biomarkers
and protein drugs. To discover the secretome that influences lung
adenocarcinoma metastasis, the hollow fiber culture (HFC) system was
used along with label-free proteomics approach to analyze cell secretomes
between CL1-0 and CL1-5 cell lines, which exhibit low and high metastatic
potentials. Among the 703 proteins quantified, 50 possessed different
levels between CL1-0 and CL1-5. PARK7 was a primary focus because
of the lack of research involving lung adenocarcinoma. The cell proliferation,
migration, and invasion properties of CL1-0, CL1-5, and A549 cells
were significantly diminished when the expression of their PARK7 proteins
was reduced. Conversely, these functions were promoted when PARK7
was overexpressed in CL1-0. In clinical expression, PARK7 levels within
tissue specimens and plasma samples were significantly higher in the
cancer group. This represents the first time the HFC system has been
used with label-free quantification to discern the elements of metastasis
in lung adenocarcinoma cell secretomes. Likewise, PARK7 has never
been researched for its role in promoting lung adenocarcinoma progression.