A Comparative Study of Oncolytic Vaccinia Viruses Harboring Different Marine Lectins in Breast Cancer Cells

Abstract

Our previous studies demonstrated that arming vaccinia viruses with marine lectins enhanced the antitumor efficacy in several cancer cells. This study aims to compare the efficacy of oncolytic vaccinia viruses harboring Tachypleus tridentatus lectin (oncoVV-TTL), Aphrocallistes vastus lectin (oncoVV-AVL), white-spotted charr lectin (oncoVV-WCL), and Asterina pectinifera lectin (oncoVV-APL) in breast cancer cells (BC). These results indicated that oncoVV-AVL elicited the highest anti-tumor effect, followed by oncoVV-APL, while oncoVV-TTL and oncoVV-WCL had lower effects in BC. Further studies showed that apoptosis and replication may work together to enhance the cytotoxicity of oncoVV-lectins in a cell-type dependent manner. TTL/AVL/APL/WCL may mediate multiple pathways, including ERK, JNK, Hippo, and PI3K pathways, to promote oncoVV replication in MDA-MB-231 cells. In contrast, these pathways did not affect oncoVV-TTL/AVL/APL/WCL replication in MCF-7 cells, suggesting that the mechanisms of recombinant viruses in MCF-7 (ER+, PR+) and MDA-MB-231 (TNBC) cells were significantly different. Based on this study, we hypothesized that ER or PR may be responsible for the differences in promoting viral replication and inducing apoptosis between MCF-7 and MDA-MB-231 cells, but the specific mechanism needs to be further explored. In addition, small-molecule drugs targeting key cellular signaling pathways, including MAPK, PI3K/Akt, and Hippo, could be conjunction with oncoVV-AVL to promote breast cancer therapy, and key pathway factors in the JNK and PI3K pathways may be related to the efficacy of oncoVV-APL/TTL/WCL. This study provides a basis for applying oncolytic vaccinia virus in breast carcinoma.

Effects of Oncolytic Vaccinia Viruses Harboring Different Marine Lectins on Hepatocellular Carcinoma Cells

“…The cell viability of Hep-3B, Huh7, or PLC/PRF/5 was assessed by MTT assay as previously described [ 30 ]. Cells were cultured for 12 h and then treated with PBS, oncoVV, or recombinant viruses at 5 or 10 MOI.…”

“…Apoptosis was assessed by flow cytometry as previously described [ 30 ]. In brief, cell lines (Hep-3B, Huh7, and PLC/PRF/5) treated with PBS, oncoVV, and recombinant vaccinia viruses were collected and then stained with Annexin V-FITC and PI.…”

“…The viral titers were determined by TCID 50 assay as previously described [ 29 , 30 ]. Cell lines (Hep-3B, Huh7, and PLC/PRF/5) were infected with viruses at 5 MOI for 0 h, 12 h, 24 h, 36 h, and 48 h. To study how lectins affect viral replication through signaling pathways, some activators or inhibitors (Selleck Chemicals LLC, Houston, TX, USA) were administered, and the drug was used 1 h prior to infection.…”

“…Proteins were assessed by WB as previously described [ 30 ]. Cells (Hep-3B, Huh7, and PLC/PRF/5) infected with oncoVV or recombinant viruses for 36 h at 5 MOI were collected and lysed.…”

“…Diluted suspensions were then added to HEK 293A cells and viral plaque holes were counted. The formula T = 7 × 10 (d + 0.5) PFU/mL (d = sum of positive proportion) was used to calculate the viral titer [ 29 , 30 ]. The levels of A27L were detected by WB.…”