Synergic effect between 5-fluorouracil and celecoxib on hypoxic gastric cancer cells

NSAIDs: Old Acquaintance in the Pipeline for Cancer Treatment and Prevention─Structural Modulation, Mechanisms of Action, and Bright Future

The limitations of current chemotherapeutic drugs are still a major issue in cancer treatment. Thus, targeted multimodal therapeutic approaches need to be strategically developed to successfully control tumor growth and prevent metastatic burden. Inflammation has long been recognized as a hallmark of cancer and plays a key role in the tumorigenesis and progression of the disease. Several epidemiological, clinical, and preclinical studies have shown that traditional nonsteroidal anti-inflammatory drugs (NSAIDs) exhibit anticancer activities. This Perspective reports the most recent outcomes for the treatment and prevention of different types of cancers for several NSAIDs alone or in combination with current chemotherapeutic drugs. Furthermore, an extensive review of the most promising structural modifications is reported, such as phospho, H₂S, and NO releasing-, selenium-, metal complex-, and natural product-NSAIDs, among others. We also provide a perspective about the new strategies used to obtain more efficient NSAID- or NSAID derivative- formulations for targeted delivery.

Pharmacodynamic mechanisms of anti-inflammatory drugs on the chemosensitization of multidrug-resistant cancers and the pharmacogenetics effectiveness

Drug resistance as a remarkable issue in cancer treatment is associated with inflammation which occurs through complex chemical reactions in the tumor microenvironment. Recent studies have implicated that glucocorticoids and NSAIDs are mainly useful combinations for inflammatory response modulation in chemotherapeutic protocols for cancer treatment. Immunosuppressive actions of glucocorticoids and NSAIDs are mainly mediated by the transrepression or activation regulation of inflammatory genes with different DNA-bound transcription factors including AP-1, NFAT, NF-κB, STAT and also, varying functions of COX enzymes in cancer cells. Interestingly, many investigations have proved the benefits of these anti-inflammatory agents in the quenching of multidrug resistance pathways. Numerous analyses on the ABC transporter promoters showed conserved nucleotide sequences with several DNA response elements that participate in transcriptional regulation. Furthermore, genetic variations in nucleotide sequences of membrane transporters were strongly associated with changes in these transporters' expression or function and a substantial impact on systemic drug exposure and toxicity. It appeared that several polymorphisms in MDR transporter genes especially MDR1 have influenced the regulatory mechanisms and explained differences in glucocorticoid responses.

Celecoxib in Cancer Therapy and Prevention - Review

BACKGROUND AND OBJECTIVES

It is generally accepted that inflammatory cells found in the tumor microenvironment are involved in the neoplastic process, promoting cell proliferation, survival, and migration. Therefore, administering anti-inflammatory medication in cancer therapy seems to be justified. A potential pathway associated with the aforementioned issue is cyclooxygenase-2 inhibition, particularly as the overexpression of this enzyme has been proven to occur in cancer tissues and is also associated with a poor prognosis in several types of human malignancies. Celecoxib, a COX-2 selective inhibitor, has been utilized for over 20 years, particularly as an anti-inflammatory, analgesic and antipyretic medication. However, to date, its antineoplastic properties have not been sufficiently investigated. In recent years, the number of research studies on the antineoplastic effects of celecoxib has increased considerably. The vast majority of publications refers to preclinical studies attempting to elucidate its mechanisms of action. Clinical trials concerning celecoxib have focused primarily on the treatment of cancers of the colon, breast, lung, prostate, stomach, head and neck, as well as premalignant lesions such as familial adenoma polyposis. In this review article authors attempt to summarise the latest research which has elucidated celecoxib use in the treatment and prevention of cancer.

CONCLUSION

Both preclinical and clinical studies have demonstrated promising results of the role of celecoxib in the treatment and prevention of cancer - the best outcome was observed in colon, breast, prostate and head and neck cancers. However, more clinical trials providing real evidence-based clinical advances of celecoxib use are needed.

Induction of hypoxia and necrosis in multicellular tumor spheroids is associated with resistance to chemotherapy treatment

Culture of cancerous cells in standard monolayer conditions poorly mirrors growth in three-dimensional architectures typically observed in a wide majority of cancers of different histological origin. Multicellular tumor spheroid (MCTS) culture models were developed to mimic these features. However, in vivo tumor growth is also characterized by the presence of ischemic and necrotic areas generated by oxygenation gradients and differential access to nutrients. Hypoxia and necrosis play key roles in tumor progression and resistance to treatment. To provide in vitro models recapitulating these events in highly controlled and standardized conditions, we have generated colorectal cancer (CRC) cell spheroids of different sizes and analyzed their gene expression profiles and sensitivity to treatment with 5FU, currently used in therapeutic protocols. Here we identify three MCTS stages, corresponding to defined spheroid sizes, characterized by normoxia, hypoxia, and hypoxia plus necrosis, respectively. Importantly, we show that MCTS including both hypoxic and necrotic areas most closely mimic gene expression profiles of in vivo-developing tumors and display the highest resistance to 5FU. Taken together, our data indicate that MCTS may mimic in vitro generation of ischemic and necrotic areas in highly standardized and controlled conditions, thereby qualifying as relevant models for drug screening purposes.

In-vitro and in-vivo inhibition of melanoma growth and metastasis by the drug combination of celecoxib and dacarbazine

Celecoxib has been found to be effective in cancer prevention and treatment. Its combination with other chemotherapeutic agents was reported to produce synergistic/additive effects on various cancers. Dacarbazine (DTIC) is one of the most commonly used drugs in the treatment of metastatic melanoma. This investigation aimed to determine the in-vitro and in-vivo effects of the drug combination of celecoxib and DTIC on melanoma growth and metastasis. Melanoma cells B16-F10 and SK-MEL-28, and female C57BL/6 mice were used for the study. Our in-vitro data showed that significant synergistic effects were obtained when celecoxib was used together with various concentrations of DTIC. A study with B16-F10 cells using flow cytometry analysis showed that the drug combination induced significantly more apoptosis than each drug used individually. Our in-vivo results showed that the drug combination was much more effective than each drug used alone for the inhibition of both melanoma growth and metastasis in the B16-F10+C57BL/6 mouse models. For melanoma growth, the median survival rates for phosphate-buffered saline (PBS) (control), celecoxib (30 mg/kg), DTIC-1 (10 mg/kg), DTIC-2 (positive control, 50 mg/kg), and the drug combination (DTIC 10 mg/kg+celecoxib 30 mg/kg) were 6, 6.5, 7.5, 7.5, and 9 days, respectively. For melanoma metastasis, the average number of metastatic tumors in murine lungs was 53.7±10.7, 31.8±18.6, 21.2±21.7, 7.0±9.0, and 0.8±2.0 for PBS, DTIC-1, celecoxib, the drug combination, and DTIC-2. Our results warrant further investigation of the combination as an effective treatment for melanoma patients.