{Reference Type}: Journal Article
{Title}: The Density of CD8+ Tumor-infiltrating Lymphocytes Correlated With Akt Activation and Ki-67 Index in Canine Soft Tissue Sarcoma.
{Author}: Nururrozi A;Miyanishi K;Igase M;Sakurai M;Sakai Y;Tanabe M;Mizuno T;
{Journal}: In Vivo
{Volume}: 38
{Issue}: 4
{Year}: 2024 Jul-Aug
{Factor}: 2.406
{DOI}: 10.21873/invivo.13620
{Abstract}: <B>OBJECTIVE: </B>The activation of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway has been implicated in canine soft tissue sarcoma (STS) and may serve as a prognostic marker. This study investigated the correlation between PI3K/Akt activation in tumor cells and tumor-infiltrating lymphocytes (TILs).<BR><B>METHODS: </B>A total of 59 STS samples were labeled via immunohistochemistry to calculate the density of TILs, including CD3+ T cells, CD8+ T cells, CD20+ B cells, and FOXP3+ regulatory T cells.<BR><B>RESULTS: </B>Forty-eight samples (81.3%) had intra-tumoral TILs with a high density of CD3+ T cells (mean: 283.3 cells/mm2) and CD8+ T cells (mean: 134.8 cells/mm2). Conversely, CD20+ B cells (mean: 73.6 cells/mm2) and FOXP3+ regulatory T cells (mean: 9.2 cells/mm2) were scarce. The abundance of CD3+/CD8+, CD3+/CD20+, and CD8+/CD20+ TILs were highly correlated in multivariate analyses (r=0.895, 0.946, and 0.856, respectively). Nonetheless, TIL density was unrelated to clinicopathological parameters (sex, age, tumor location, breed) and tumor grade. The abundance of CD8+ T cells was positively correlated with the activation of PI3K/Akt, indicating that samples with high levels of phospho-Akt and phospho-S6 tend to have a higher CD8+ T cell density (p=0.0032 and 0.0218, respectively). Furthermore, TIL density was correlated with the Ki-67 index, a tumor proliferation and growth marker. Samples with a high Ki-67 index had a significantly higher abundance of CD3+ T cells, CD8+ T cells, and CD20+ B cells (p=0.0392, 0.0254, 0.0380, respectively).<BR><B>CONCLUSIONS: </B>PI3K/Akt pathway activation may influence the infiltration of CD8+ T cells within the tumor microenvironment in canine STS. Prospective studies involving a higher number of cases are warranted to confirm these findings.