Regorafenib as a potential adjuvant chemotherapy agent in disseminated small colon cancer: Drug selection outcome of a novel screening system using nanoimprinting 3-dimensional culture with HCT116-RFP cells

Abstract

Colon cancer is one of the leading causes of cancer death worldwide. Adjuvant chemotherapy following primary surgical treatment is suggested to be beneficial in eradicating invisible disseminated small tumors in colon cancer; however, an effective drug remains to be developed. Recently, we reported a novel drug screening system using a nanoimprinting 3-dimensional (3D) culture that creates multicellular spheroids, which simulate in vivo conditions and, thereby, predict effective drugs in vivo. This study aimed to perform drug selection using our recently developed 3D culture system in a human colon cancer HCT116 cell line stably expressing red fluorescent protein (HCT116-RFP), to determine the most effective agent in a selection of clinically used antitumor agents for colon cancer. In addition, we confirmed the efficacy of the selected drug regorafenib, in vivo using a mouse model of disseminated small tumors. HCT116-RFP cells were cultured using a nanoimprinting 3D culture and in vitro drug selection was performed with 8 clinically used drugs [bevacizumab, capecitabine, cetuximab, 5-fluorouracil (5-FU), irinotecan, oxaliplatin, panitumumab and regorafenib]. An in vivo study was performed in mice bearing HCT116-RFP intraperitoneally disseminated small tumors using 3'-[18F]-fluoro-3'-deoxythymidine-positron emission tomography and fluorescence microscopy imaging to evaluate the therapeutic effects. Regorafenib was determined to be the most effective drug in the 3D culture, and significantly inhibited tumor growth in vivo, compared to the untreated control and 5-FU-treated group. The drug 5-FU is commonly used in colon cancer treatment and was used as a reference. Our results demonstrate that regorafenib is a potentially efficacious adjuvant chemotherapeutic agent for the treatment of disseminated small colon cancer and, therefore, warrants further preclinical and clinical studies.

Anti-tumoral activity of single and combined regorafenib treatments in preclinical models of liver and gastrointestinal cancers

“…Moreover, daily regorafenib administration at 30 mg/kg suppressed tumor growth in a highly aggressive murine CT26 metastatic colon cancer model 55 . Although similar results were observed in different HCT116-bearing mouse models 53,56 , it has been noted that a lower regorafenib dose, such as 10 mg/kg/day, can delay tumor growth 47 , even in oxaliplatin-refractory CRC-PDX 50 .…”

“…A study performed with the human CRC cell lines HCT15, DLD-1, HT29, and HCT116 showed a drastic decrease in cell viability when regorafenib was administered at doses higher than 5 µM 47 , an effect that was also observed in SW480 48 , KM12SM, Caco-2, LoVo, WiDr, and RKO CRC cells 49 . Cell proliferation inhibition was also corroborated in a panel of in vitro models 50–52 , as well as in an HCT116 nanoimprinting 3D culture 53 and in cell lines established from CRC primary tumors 54 . Moreover, daily regorafenib administration at 30 mg/kg suppressed tumor growth in a highly aggressive murine CT26 metastatic colon cancer model 55 .…”

Integrated treatment using intraperitoneal radioimmunotherapy and positron emission tomography-guided surgery with 64Cu-labeled cetuximab to treat early- and late-phase peritoneal dissemination in human gastrointestinal cancer xenografts

“…Human colon cancer HCT116 cells (CCL-247; American Type Cell Collection) stably expressing RFP (HCT116-RFP), established in our previous study [ 48 ], were used. Human gastric cancer NUGC4-RFP cells (Anticancer) were also used in this study.…”

Concise Review: 3D cell culture systems for anticancer drug screening

“…Using polymeric microparticle surfaces to create 3D tumors, they found that 2D MCF7 cells were significantly more sensitive to these drugs than 3D MCF7 cells, with a 12-to 23-fold disparity in the IC50 values. The study also showed that the sum of collagen in the 3D model was 2 times greater than that of 2D condition and the expression of many genes were different, possibly accounting for the difference in responses to the drugs (Horning et al, 2008 Based on their 3D culture studies, the authors were able to demonstrate effective and non-effective drugs for colon cancer treatment (Yoshii et al, 2016). …”