The "stone-like" pattern of LC3A expression and its clinicopathologic significance in hepatocellular carcinoma

Autophagy is an evolutionarily conserved process that involves lysosomal degradations of cellular organelles. Microtubule-associated protein 1 light chain 3A (LC3A), an autophagic gene, is differentially expressed in human cancers. However, the relationship between LC3A expression and hepatocellular carcinoma (HCC) has not been investigated. Tissue microarray-based immunohistochemistry was used to examine the expression patterns of LC3A in HCC. The resulting data were analyzed using receiver operating characteristic curves, Spearman's rank correlation, Kaplan-Meier plots and Cox proportional hazards regression modeling. Two distinct patterns of LC3A expression were observed in HCC: "stone-like" structuring and diffuse cytoplasmic expression. High levels of LC3A expression were more frequently observed in HCC tissues compared to the adjacent non-tumorous tissue. Correlation analyses indicated that high expression of the "stone-like" LC3A was correlated with greater levels of serum AFP, poorer tumor differentiation and the presence of vascular invasion. Kaplan-Meier survival analysis showed a significant association between high expression of the "stone-like" LC3A and unfavorable prognosis (P<0.001). Importantly, multivariate analysis (P<0.05) identified the "stone-like" expression of LC3A in HCC as an independent prognostic factor. Collectively, our data provide compelling evidence that "stone-like" expression of LC3A plays an important role in HCC progression and may act as a biomarker of prognosis for patients with HCC.