Enhanced Therapeutic Efficacy of the Nanoscale Fluoropyrimidine Polymer CF10 in a Rat Colorectal Cancer Liver Metastasis Model

Combination chemotherapy regimens that include fluoropyrimidine (FP) drugs, e.g., 5-fluorouracil (5-FU), are central to the treatment of colorectal cancer liver metastases (CRLMs), a major cause of cancer mortality. We tested a second-generation FP polymer, CF10, in a CC531/WAGRij syngeneic orthotopic rat model of liver metastasis to determine if CF10 improved response relative to 5-FU. CF10 displayed increased potency relative to 5-FU in CC531 rat colorectal cancer cells based on clonogenic assay results and caused increased apoptosis, as shown using a live/dead assay. The increased potency of CF10 to CC531 cells was associated with increased replication stress, as assessed by Western blot for biomarkers of ATR/Chk1 and ATM/Chk2 pathway activation. CF10 dosed to deliver equivalent FP content as an established dose of 5-FU in rats (50 mg/kg) did not cause weight loss in WAGRij rats even when combined with ethynyl uracil (EU), an inhibitor of dihydropyrimidine dehydrogenase, the enzyme primarily responsible for 5-FU degradation in the liver. In contrast, 5-FU caused significant weight loss that was exacerbated in combination with EU. Importantly, CF10 was significantly more effective than 5-FU at inhibiting tumor progression (~90% reduction) in the CC531/WAG/Rij CRLM model. Our results reveal strong potential for CF10 to be used for CRLM treatment.

Synthesis and biological evaluation of benzofuran piperazine derivatives as potential anticancer agents

This work describes about the synthesis and evaluation of substituted benzofuran piperazines as potential anticancer agents. The synthesized candidates have been evaluated for their cell proliferation inhibition properties in six murine and human cancer cell lines. In vitro evaluation of apoptosis and cell cycle analysis with the lead candidate 1.19 reveals that necrosis might be an important pathway for the candidate compounds to cause cell death. Further, in vivo evaluation of the lead compound shows that this candidate is well tolerated in healthy mice. Additionally, an in vivo anticancer efficacy study in mice using a MDA-MB-231 xenograft model with the lead compound provides good anti-cancer efficacy.

Viral Vectors Expressing Interleukin 2 for Cancer Immunotherapy

Interleukin 2 (IL-2) plays a crucial role in T cell growth and survival, enhancing the cytotoxic activity of natural killer and cytotoxic T cells and thus functioning as a versatile master proinflammatory anticancer cytokine. The FDA has approved IL-2 cytokine therapy for the treatment of metastatic melanoma and metastatic renal cell carcinoma. However, IL-2 therapy has significant constraints, including a short serum half-life, low tumor accumulation, and life-threatening toxicities associated with high doses. Oncolytic viruses (OVs) offer a promising option for cancer immunotherapy, selectively targeting and destroying cancer cells while sparing healthy cells. Numerous studies have demonstrated the successful delivery of IL-2 to the tumor microenvironment without compromising safety using OVs such as vaccinia, Sendai, parvo, Newcastle disease, tanapox, and adenoviruses. Additionally, by engineering OVs to coexpress IL-2 with other anticancer transgenes, the immune properties of IL-2 can be further enhanced. Preclinical and clinical studies have shown promising antitumor effects of IL-2-expressing viral vectors, either alone or in combination with other anticancer therapies. This review summarizes the therapeutic potential of IL-2-expressing viral vectors and their antitumor mechanisms of action.

Abstract 6178: A novel second-generation nano-fluoropyrimidine to treat metastatic colorectal cancer and overcome 5-fluorouracil resistance

Colorectal cancer (CRC) is the 3rd leading cause of cancer-related mortality. The mortality associated with colon cancer results notably from metastatic disease (mCRC), with a 5-year survival rate for patients with stage IV CRC being < 14%. Despite extensive efforts towards developing personalized therapies, limited success has been achieved and chemotherapeutic regimens that include the fluoropyrimidine (FP) drug 5-fluorouracil (5-FU) are central to patient management. While using 5-FU-based regimens such as FOLFOX and FOLFIRI in combination with biologics confer a survival benefit, their ineffectiveness at promoting long-term survival in a substantial fraction of mCRC patients and associated toxicities limits their use. This underscores the pressing need to develop improved FP drugs. To overcome the limitations of 5-FU that include resistance due to elevated expression of thymidylate synthase (TS) and inefficient anabolic metabolism to FdUMP, the TS-inhibitory/active metabolite, we are developing FP polymers consisting of single-stranded DNA with FdUMP (only active metabolite) as the repeating nucleotide unit. Our therapeutic objective is to initiate a Phase I clinical trial with a new 2nd generation nanoscale FP polymer (CF10) that demonstrates promising anticancer effects in several preclinical models and significantly lower systemic toxicity. We observed that CF10 displayed significantly higher anti-tumor activity than 5-FU in flank and syngeneic tumor models. Additionally, CF10 treatment improved survival (84.5 days vs 32 days; P < 0.0001) relative to 5-FU in an orthotopic HCT-116-luc colorectal cancer mice model that spontaneously metastasized to the liver. Interestingly, a reduction in metastatic tumor burden in the CF10 treatment group led us to hypothesize that CF10 could inhibit the TS-mediated EMT phenotype and pro-metastatic activities in colorectal cancer cells (CRCs). This was supported by increased vimentin, decreased E-cadherin expression, and increased cell migration and invasion in TS-overexpressing CRC cells (“Tet-on” system). Alkaline comet assay, immunofluorescence imaging, and immunoblot identified significantly higher replication stress with CF10 treatment than 5-FU in mouse, rat, and human-established CRC cell lines and primary CRC cells. Strikingly, we also discovered that CF10 attenuates the growth of TS-overexpressing primary colonoids. In conclusion, CF10 induces increased replication stress compared to a similar concentration of conventional drugs. Our findings suggest the significance of elevated TS in CRC metastatic progression and 5-FU resistance and demonstrate that CF10 may be effective at inhibiting CRC metastatic progression. CF10 may be a successful candidate for early-phase clinical trials to treat mCRC.

Citation Format: Naresh Sah, Pamela Luna, Chinnadurai Mani, William Gmeiner, Komaraiah Palle. A novel second-generation nano-fluoropyrimidine to treat metastatic colorectal cancer and overcome 5-fluorouracil resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6178.

Sulfasalazine-induced drug rash with eosinophilia and systemic symptoms syndrome in a seronegative spondyloarthritis patient: A Case report

The objectives were to evaluate drug rash with eosinophilia and systemic symptoms syndrome due to sulfasalazine and to carry out the pharmacoeconomic assessment associated with this adverse drug reaction (ADR). A 37-year woman was presented with rashes, fever, cough, and dyspnea. In the past 3 months, she was on sulfasalazine for inflammatory polyarthritis and seronegative spondyloarthritis. The diagnosis was based on raised eosinophils count, breathing difficulty, and typical pattern of rashes. Significant improvement was seen after discontinuation of sulfasalazine and with the initiation of parenteral corticosteroids. The casualty of this ADR was “probable” based on RegiSCAR, WHO, and Naranjo casualty assessment scales. Preventability, severity was assessed and total cost for management of the ADR was found to be ' 12,126. Thus, ADRs not only adds to patient sufferings but also increase the economic burden. Health-care providers need to be made aware of potentially fatal ADRs associated with sulfa drugs and should be keen to report such ADRs to drug safety authorities.

Growth, Purification, and Titration of Oncolytic Herpes Simplex Virus

Oncolytic viruses (OVs), such as the oncolytic herpes simplex virus (oHSV), are a rapidly growing treatment strategy in the field of cancer immunotherapy. OVs, including oHSV, selectively replicate in and kill cancer cells (sparing healthy/normal cells) while inducing anti-tumor immunity. Because of these unique properties, oHSV-based treatment strategies are being increasingly used for the treatment of cancer, preclinically and clinically, including FDA-approved talimogene laherparevec (T-Vec). Growth, purification, and titration are three essential laboratory techniques for any OVs, including oHSVs, before they can be utilized for experimental studies. This paper describes a simple step-by-step method to amplify oHSV in Vero cells. As oHSVs multiply, they produce a cytopathic effect (CPE) in Vero cells. Once 90-100% of the infected cells show a CPE, they are gently harvested, treated with benzonase and magnesium chloride (MgCl2), filtered, and subjected to purification using the sucrose-gradient method. Following purification, the number of infectious oHSV (designated as plaque-forming units or PFUs) is determined by a "plaque assay" in Vero cells. The protocol described herein can be used to prepare high-titer oHSV stock for in vitro studies in cell culture and in vivo animal experiments.