Topics in Anti-Cancer Research

Exosomes are extracellular vesicles that are 30-150 nm in diameter. Exosomes have recently emerged as critical mediators of cell-cell communication by the transfer of DNA, RNA, and protein structured macromolecules between cells and tissues. With the advantage of the distant endocrine signalling, cancer cells use exosomes to suppress the immune system, next contribute to the formation of premetastatic niches and angiogenesis. On the other hand, researchers have been benefited from the immunosuppressive, natural carrier, and tissue regenerating roles of exosomes and disclosed patents that are claiming the utilities of exosomes for treating chronic inflammation, autoimmunity related diseases, targeted drug delivery vehicles, and tissue regenerating agents. Moreover, the use of exosomes as vaccine components to prevent cancer, therapeutic molecules for cancer treatment, and the host of biomarkers for the diagnosis and prognosis of cancer are among the issues that are protected by recent patents. The most inspiring one among them could be the incorporation of a therapeutic siRNA that is complementary to oncogenic KRASG12D into CD47+ exosomes for the treatment of pancreatic cancer. The other one could be the demonstration of the utility of exosomes secreted from dendritic as a cancer vaccine component in phase II clinical trial. It is clear that we have started to understand the fundamentals of exosomes. However, more studies are needed to develop exosomebased cancer vaccines, drug delivery vehicles, immune-stimulating agents that evoke immune cells to kill the cancer cells, and diagnostic and prognostic markers for monitoring cancer in the next years.

The most common malignancy in the gastrointestinal tract is colorectal carcinomas (CRC), which is the second most common cancer in women and the third most in men worldwide. Adenomas are the most frequently observed precursor lesions for CRC. Two basic pathways have been defined for CRCs: the classical adenomacarcinoma sequence and serrated pathway developing from sessile serrated lesions or adenomas. In the previously reported literature, there is no potential for malignancy, but now the serrated neoplasia pathway is observed in approximately 30% of all CRCs. In large colonoscopic series studies, the prevalence of serrated polyp is approximately 20%. Colorectal serrated lesions are characterized by sawtooth or stellate morphological features of the epithelium. For sessile serrated lesion (SSL) definition, according to the World Health Organization (WHO) Classification of Tumors of the Digestive System 2019, the presence of at least 1unequivocal distorted crypt is considered sufficient for diagnosis. There is major variability in the morphology of colorectal serrated lesions or polyps, and as a consequence, a number of pathological subtypes have been described and 3 significant types have been defined; hyperplastic polyp (HP), sessile serrated lesion (SSL), and traditional serrated adenoma (TSA). HP is the most common lesion among all serrated polyps, and the potential for colorectal cancer development is very low. Improving the detection of SSLs reduces both the incidence and mortality of CRCs and reduces the risk of developing cancer of interval cancers. In this article, we will discuss serrated polyps, nomenclature, the particularly associated risk of cancer, terminology and classifications, molecular features and colonoscopic follow-up with the current designation.

Background: Plaque brachytherapy has been introduced as a treatment for ocular melanoma, an intraocular tumor, and is an available alternative to eye enucleation. Brachytherapy is one of the radiotherapy methods, which uses radioactive sources near or on the tumor.

Introduction: So far, various plaques have been used to treat eye tumors. The aim of this research is the development of radioactive material for brachytherapy plaques.

Method: In order to introduce and produce new brachytherapy plaques, all the isotopes of the periodic table of elements have been identified, and the mother and daughter of elements whose mother had long half-life beta decay and its daughter had a short halflife have been identified and the method of mother production has been examined.

Result: After reviewing, two new ¹⁸⁸W/¹⁸⁸Re and ¹⁴⁴Ce/¹⁴⁴Pr plaques have been selected for use in brachytherapy.

Conclusion: Each of the new plaques has a special advantage in comparison with old plaques. The 2D dose distribution of ¹⁸⁸W/¹⁸⁸Re and ¹⁴⁴Ce/¹⁴⁴Pr plaques in eye and tumor was obtained and was compared with old plaques.

ShcA proteins are the family of adaptor proteins that mediate biological responses by transducing extracellular signals into intracellular signals. ShcA family consists of three different alternatively spliced or alternative translational initiated isoforms known as p66Shc, p52Shc and p46Shc. The p52and p46Shc isoforms are usually involved in promoting cell growth, mediating their action by activating mitogen-activated protein kinases (MAPK) and phosphoinositide-3-kinase/Akt signalling pathways. However, the p66Shc isoform acts as a dual player in cell development and is involved in stimulating both cell proliferative and apoptotic pathways. Any deregulation in the expression of ShcA proteins and pathways regulated by ShcA proteins results in the occurrence of different types of cancerous diseases, including breast cancer, thyroid cancer, prostate cancer and lung cancer. Aberrations in the expression of ShcA proteins have been demonstrated to promote key elements of cancer progression, including cell migration, cell proliferation, metabolic reprogramming, angiogenesis and tumorigenesis. Based on all these studies, the present chapter focuses on the structure of ShcA proteins and their role in promoting metastasis and progression of various cancers. Understanding the role of ShcA proteins may provide new tools for therapeutic interventions in dreadful cancer disease.

Cancer is a disease that causes a huge health burden for communities. Despite the great progress made in diagnostic tools for cancer and the advancement of treatment strategies, cancer is still one of the commonest causes of death in the world. Melatonin, a hormone produced mainly by the pineal gland, possesses an anti-cancer property. The discovery of this effect of melatonin on cancer cells was a breakthrough in the field of cancer research. Several lines of evidence support this property of melatonin, including in vitro and in vivo studies and clinical trials. This effect of melatonin was examined in various types of cancer, and a consensus has been reached with regard to its oncostatic/anti-cancer effect. Multiple mechanisms have been proposed for this effect of melatonin, among which are the anti-oxidant, antiinflammatory, anti-estrogen/androgen, anti-angiogenic, and pro-apoptotic actions of melatonin. This chapter presents an account on the anti-cancer effect of melatonin, focusing on mechanisms of action by presenting examples of cancer types, including the most common types of cancer in the world: cancers of the lung, prostate, breast, and colon, as well as ovarian cancer.

The available therapy for cancers mostly revolves around chemotherapy, radiation, immunotherapy, and surgery, but these treatment modalities are not satisfactorily treating the patients and are associated with various side effects, pain, immune reduction, trauma, and also induce drug resistance in some patients. Besides, these treatments do not treat the disease's origin but eliminate the tumor itself somewhat without confirmation of avoiding its metastasis. Therefore, there is a need to develop a new effective therapy to treat cancer patients successfully. Hormones naturally present in the human body for controlling various biological and physiological functions also possess potential capabilities to treat different types of cancers. Both preclinical and clinical data show that hormones include anticancer abilities, are controlled by hormonal managing. This chapter has discussed the cellular and molecular role of different types of hormones in treating various kinds of cancers and other pertinent topics related to their impact on stem cell functionality and cancer management.