Microbial lectins as a potential therapeutics for the prevention of certain human diseases.

Lectins are protein or glycoprotein molecules with a specific ability to bind to carbohydrates. From viruses to mammals, they are found in various organisms and exhibit remarkable diverse structures and functions. They are significant contributors to defense mechanisms against microbial attacks in plants. They are also involved in functions such as controlling lymphocyte migration, regulating glycoprotein biosynthesis, cell-cell recognition, and embryonic development in animals. In addition, lectins serve as invaluable molecular tools in various biological and medical disciplines due to their reversible binding ability and enable the monitoring of cell membrane changes in physiological and pathological contexts. Microbial lectins, often referred to as adhesins, play an important role in microbial colonization, pathogenicity, and interactions among microorganisms. Viral lectins are located in the bilayered viral membrane, whereas bacterial lectins are found intracellularly and on the bacterial cell surface. Microfungal lectins are typically intracellular and have various functions in host-parasite interaction, and in fungal growth and morphogenesis. Although microbial lectin studies are less extensive than those of plants and animals, they provide insights into the infection mechanisms and potential interventions. Glycan specificity, essential functions in infectious diseases, and applications in the diagnosis and treatment of viral and bacterial infections are critical aspects of microbial lectin research. In this review, we will discuss the application and therapeutic potential of viral, bacterial and microfungal lectins.

Therapeutic potential of lectins in the treatment of breast cancer: A review.

Breast cancer is one of the most common malignancies and the leading cause of cancer-related deaths in women. There are 3 major subtypes of breast cancer that are distinguished by expression of estrogen or progesterone receptors and ERBB2 gene amplification. The 3 subtypes have different risk profiles and treatment strategies. Abnormal glycosylation is thought to play an important role in the development of the tumorigenic and metastatic phenotype of breast cancer and resistance to therapy. They may also be a potentially attractive target for breast cancer treatment. Proteins such as lectins, a family of carbohydrate-binding proteins found in a variety of organisms from viruses to humans, can specifically interact with abnormally glycosylated carbohydrate residues in cancer cells and induce cytotoxic effects. In recent years, there has been a growing number of research addressing studies demonstrating their antitumorigenic and antimalignant effects. This review summarizes recent findings on lectins from plants, animals, fungi, and bacteria that are potentially therapeutic agents against breast cancer and outlines the basis of their mechanism of action.

RNA-Seq transcriptome analysis reveals Maackia amurensis leukoagglutinin has antitumor activity in human anaplastic thyroid cancer cells.

BACKGROUND: Lectins are carbohydrate-binding molecules that can bind specifically to the sugar residues of glycoconjugates and are found in almost all organisms. Plant lectins subjected to many studies reported exhibiting anti-cancer activity. This study aimed to investigate the possible molecular mechanisms of Maackia amurensis leukoagglutinin II (MAL-II) treated ATCCs. METHODS AND RESULTS: We tested the effects of MAL-II, which is isolated from Amur seeds, on cancerous features of 8505C human anaplastic thyroid cancer cells (ATCCs) on a large scale using RNA-Seq. Transcriptome analysis was performed using Illumina next-generation sequencing technology by using cDNA libraries obtained from total RNA isolates of ATCCs treated with 0.25 µM MAL-II for 24 h. Gene ontology and pathway enrichment analysis were performed for the systematic analysis of gene functions. Moreover, we validated RNA-Seq findings using qPCR. Our results showed that many cancer-related genes such as TENM4, STIM2, SYT12, PIEZO2, ABCG1, SPNS2, ARRB1, and IRX5 were downregulated and many anticancer genes such as HSPA6, G0S2, TNFAIP3, GEM, GADD45G, RND1, SERPINB2, and IL24 were upregulated. Also, pathway enrichment analysis showed that differentially expressed genes were found to be associated with Ras, p53, and apoptosis signaling pathways, which are some important signal transduction pathways in development, proliferation, stem cell control, and carcinogenesis. CONCLUSION: Collectively, our results show that MAL-II treatment reveals significant antitumor activity by changing the expression of many cancer-related genes and implies that MAL-II treatment might be a potential candidate molecule to inhibit the malignancy of human anaplastic thyroid cancer.

The effect of plant lectins on the survival and malignant behaviors of thyroid cancer cells.

Altered or aberrant glycosylation is a common phenomenon in cancer cells and it originates from changes in the expression of the enzymes, glycosyltransferase, and glycosidase which up-regulate in response to some oncogenes in the glycan synthesis pathway. In this present study, it has been aimed to determine the alteration of sialic acid and fucose expressions in the cell surface of human thyroid carcinoma cells and investigate the changes in tumorigenic and malignant characters after treating them with specific plant lectins. Our study showed that the cell surface glycan chains of anaplastic 8305C, follicular FTC-133, and papillary K1 thyroid carcinoma cells were rich in α-2,6, α-2,3, sialic acid, and α-1,6 fucose residues. When the cells were treated with specific doses of Maackia amurensis lectin II (MAL), Sambucus nigra agglutinin (SNA), and Aleuria aurantia lectin (AAL) which have specific binding capacity for the detected glycan residues, respectively their cancerous traits changed dramatically. Remarkable findings obtained from MAL treatment leading to necrosis in 8505C cells without any toxicity for normal thyroid epithelial cells but it had proliferative effect on K1 and FCT-133 cells. Besides, MAL and SNA treatment decreased the mobility of 8505C and K1 cells. MAL and SNA lectins dramatically reduced the endothelial affinity of the cells and AAL significantly attenuated that of 8050C and K1 cells but not FTC-133. These results suggest that altered cell surface glycosylation in thyroid cancer seems to be a strong candidate for developing new therapeutic strategies.