No abstract

Background: Cancer is one of the most fatal diseases across the world and it was reported that 90% of cancer fatality depends on its angiogenesis potential. Black seed or Nigella sativa L. is a medicinal plant native to southwest Asia. N. sativa has been used for medicinal purposes for centuries and predominantly has bioactive components like Thymoquinone, which is used as a candidate for anti-cancer and anti-angiogenesis drugs. Methods: Callus was induced from leaf tissue, after that alcoholic extracts were prepared from three-month-old calluses. Thymoquinone content was measured by HPLC methods. AGS cell line was cultured and treated with standard Thymoquinone and extracts from callus. Then, cell proliferation, expression of angiogenic factor (VEGF-A gene), and apoptosis test were done by MTT assay, real-time PCR and Annexin-v kit, respectively. Results: HPLC found the maximum amount of Thymoquinone in the extract of leaf calluses, which were grown in the dark. MTT assay revealed that particular doses of extracts reduced cell proliferation. Real-time and Fluorescence- Activated Cell Sorting (FACS) results demonstrated that standard Thymoquinone and callus extracts down-regulated the VEGF-A gene expression, and all three induced apoptosis in the AGS cell line. Conclusion: It has been shown that TQ has pro-apoptotic and anti-metastatic effects on stomach cancer cell line, and these properties can introduce it as an anti-cancer drug in the near future.

Immunotherapy is considered a promising approach for cancer treatment. An important strategy for cancer immunotherapy is the use of cancer vaccines, which have been widely used for cancer treatment. Despite the great potential of cancer vaccines for cancer treatment, their therapeutic effects in clinical settings have been limited. The main reason behind the lack of significant therapeutic outcomes for cancer vaccines is believed to be the immunosuppressive tumor microenvironment (TME). The TME counteracts the therapeutic effects of immunotherapy and provides a favorable environment for tumor growth and progression. Therefore, overcoming the immunosuppressive TME can potentially augment the therapeutic effects of cancer immunotherapy in general and therapeutic cancer vaccines in particular. Among the strategies developed for overcoming immunosuppression in TME, the use of toll-like receptor (TLR) agonists has been suggested as a promising approach to reverse immunosuppression. In this paper, we will review the application of the four most widely studied TLR agonists including agonists of TLR3, 4, 7, and 9 in cancer immunotherapy.