Antiadhesive antibodies targeting E-cadherin sensitize multicellular tumor spheroids to chemotherapy in vitro.
Multicellular resistance, a subtype of therapeutic resistance manifested in cancer cells grown as three-dimensional multicellular masses, such as spheroids in vitro and solid tumors in vivo, occurs with respect to a variety of anticancer treatment strategies including chemotherapy, ionizing radiation, and even host-mediated antibody-dependent cellular cytotoxicity. Previous studies from our laboratory have shown that multicellular resistance to chemotherapy demonstrated by aggregates of EMT-6 murine mammary carcinoma cells can be overcome by using hyaluronidase to disrupt intercellular adhesive interactions and associated patterns of protein expression. In this proof of principle study, we explored the concept of antiadhesive chemosensitization in the context of human cancer cells by using a monoclonal antibody to disrupt E-cadherin-mediated cell-cell interactions in multicellular spheroids of HT29 human colorectal adenocarcinoma. In so doing, we found that disruption of E-cadherin-mediated adhesion sensitizes multicellular spheroids of HT29 in vitro to treatment with 5-fluorouracil, paclitaxel, vinblastine, and etoposide but not cisplatin. Furthermore, we have found that antibody-mediated blockage of E-cadherin function leads to decreased expression and activity of protein kinase C alpha and beta1, both of which have previously been implicated in chemoresistance exhibited by HT29 cells; however, we have found that the chemosensitization effects of the anti-E-cadherin antibody are independent of its influence on protein kinase C beta1.
Molecular and Cellular Biology Research, Sunnybrook and Women's College Health Sciences Center and Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.
Shane K
SK
Green
Giulio
G
Francia
Ciro
C
Isidoro
Robert S
RS
Kerbel
D000818:Animals; D000906:Antibodies / Q000276:immunology* / Q000627:therapeutic use*; D015820:Cadherins / Q000276:immunology*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D004351:Drug Resistance / Q000187:drug effects; D005047:Etoposide / Q000494:pharmacology; D005472:Fluorouracil / Q000494:pharmacology; D006801:Humans; D051379:Mice; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D017239:Paclitaxel / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism; D064546:Protein Kinase C beta; D018874:Spheroids, Cellular; D014747:Vinblastine / Q000494:pharmacology
D000906:Antibodies; D015820:Cadherins; D014747:Vinblastine; D005047:Etoposide; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D017239:Paclitaxel; D005472:Fluorouracil