According to the ECCB, cancer represents the transition of a genomically damaged multicellular cell to a lower level of cell organization, controlled by the ancestral gene regulatory network (GRN) from the ancestral compartment of human and metazoan genomes. Cancer adopts ancient mechanisms and rules of the common ancestor, similar to those observed in parasitic amoebae. In cancer, the productive cell line generating CSCs is a non-gametogenic cancer germline. This germline proliferates through asymmetric cell division (ACD phenotype). CSCs lack proliferative capacity; they persist in hypoxic niches in a quiescent cell state or transition to an amplifying cell state that performs cyst-like polyploidization cycles, giving rise to precursors and CSCs capable of differentiation. Malignization arises from genomically dysfunctional tetraploid germline cells (DSCD phenotype) that proliferate in a precancerous stage through symmetric cell cycles. DSCD progeny undergo homotypic fusion, forming multinucleated genome repair syncytia (MGRS pathway) driving carcinogenesis. During tumorigenesis, metastasis, and recurrence, subsequent germline clones initiate a cascade of increasingly pathogenic CSCs through mechanisms such as heterotypic cell fusion, soma-to-germ transition, and polyploid giant cell structures (PGCCs). Irradiation and chemotherapies drive some of the very few surviving but dysfunctional CSCs through a PGCC repair pathway homologous to the MGRS pathway of carcinogenesis. The large number of PGCCs during metastasis and recurrence results from the perpetual germline cell damage and CSC poverty induced by oxygen levels above 6.0% O2 (germline hyperoxia).

According to evolutionary cancer cell biology ECCB, cancer stem cells do not arise from normal stem cells, but rather from the functional ACD phenotype of the germline. This phenotype proliferates through asymmetric cell division, producing self-renewing cells and non-proliferating daughter cells with cancer stem cell qualities (CSCs). ECCB posits that cancer stem cells themselves do not proliferate. Similar to protists, there is a close reciprocal relationship between both sister cells that collectively form a germ and stem cell lineage. These sister cells share functional roles: the proliferating cancer germline cells generate stem cells, while the non-proliferating cancer stem cells accumulate progenitor cells for new germline clones. ECCB distinguishes between primary CSCs, which are associated with carcinogenesis and primary tumors, and secondary CSCs, which are linked to metastases. This unicellular stem cell system is homologous to that of parasitic protists, such as amoebae. Both cancer stem cells and amoebae stem cells are generated by an oxygen-sensitive germline and are vulnerable to damage when oxygen levels exceed 6.0% (germline hyperoxia). Oxygen concentrations above this threshold can damage the germline genome. Dysfunctional germline cells do not undergo senescence; instead, they continue to cycle through defective symmetric cell cycles However, to regain functionality, the germline genome requires repair by hyperpolyploid giant cells known as native PGCCs, which are homologous to the multinucleated genome repair structures MGRS found in protists. Native PGCCs differ in some respects from genotoxic-induced PGCCs

Ovarian cancer is among the most common causes of female mortality. Despite improvements in diagnostic methods, non-specific symptoms and delayed gynecological exams can lead to late-stage ovarian tumor discovery. In this study, the effect of an anti-cancer compound, 3-amino-N-(3-chloro-2-methylphenyl)-5-oxo-5,6,7,8-tetrahydrothieno[2,3-b]quinoline-2-carboxamide (Compound 1) was examined. Cytotoxicity, apoptosis, and metabolomic changes in ovarian cancer cell lines SK-OV-3 and OVCAR-3, as well as glycosphingolipid (GSL) expression, both on cancer stem cells (CSCs), marked as CD49f+ and non-CSCs (CD49f-) were explored. Treatment with Compound 1 reduced the percentage of CSCs compared to non-treated cells (P < 0.001). The expression of eight GSLs on CSCs and non-CSCs was examined using flow cytometry. Both cell lines showed a change in the glycophenotype of the cells, either up or down of its expression, after the treatment. These findings raise the possibility of specifically targeting CSCs in ovarian cancer therapy. Additionally, treatment of Compound 1 resulted in a statistically significant increase in both early and late apoptosis (P<0.001) suggesting a pivotal role in initiating programmed cell death by the apoptotic pathway. The metabolic analysis revealed that the treated cancer cells showed reduced metabolic activity compared to the control group (P < 0.001)

The global prevalence of cancer is on the rise, and while targeted therapies, early diagnosis, im-munotherapies, and conventional personalized chemotherapy have significantly upgraded out-comes for cancer patients, there is still a significant likelihood that cancer cannot be fully eradi-cated. Cancer stem-like cells (CSCs) and Epithelial-mesenchymal transition (EMT) exhibit pivotal roles in cancer cell metastasis, tumor recurrence, chemotherapy resistance, and cancer cell death, among other processes. This review aims to elucidate the molecular mechanisms underlying EMT and CSCs, their interplay, associated signaling pathways, and regulation of the EMT process and the initiation of CSCs. EMT induction confers mesenchymal properties and the potential of cancer cells to adopt the CSC state. These processes are intricately associated with the regulation of Notch and Wnt signaling pathways, transforming growth factor-β (TGF-β), as well as the expres-sion of miRNAs. Further exploring the relationship between EMT and CSCs is essential for the development of new chemotherapeutic strategies and the identification of novel therapeutic tar-gets, and hence, the development of therapeutic strategies targeting EMT, or CSCs holds promise for improving cancer therapy.