Polyploid Giant Cancer Cells Generated from Human Cytomegalovirus-Infected Prostate Epithelial Cells

BACKGROUND

Prostate cancer is the most commonly diagnosed malignancy and the sixth leading cause of cancer death in men worldwide. Chromosomal instability (CIN) and polyploid giant cancer cells (PGCCs) have been considered predominant hallmarks of cancer. Recent clinical studies have proven the association of CIN, aneuploidy, and PGCCs with poor prognosis of prostate cancer (PCa). Evidence of HCMV transforming potential might indicate that HCMV may be involved in PCa.

METHODS

Herein, we underline the role of the high-risk HCMV-DB and -BL clinical strains in transforming prostate epithelial cells and assess the molecular and cellular oncogenic processes associated with PCa.

RESULTS

Oncogenesis parallels a sustained growth of "CMV-Transformed Prostate epithelial cells" or CTP cells that highly express Myc and EZH2, forming soft agar colonies and displaying stemness as well as mesenchymal features, hence promoting EMT as well as PGCCs and a spheroid appearance.

CONCLUSIONS

HCMV-induced Myc and EZH2 upregulation coupled with stemness and EMT traits in IE1-expressing CTP might highlight the potential role of HCMV in PCa development and encourage the use of anti-EZH2 and anti-HCMV in PCa treatment.

The Price of Human Evolution: Cancer-Testis Antigens, the Decline in Male Fertility and the Increase in Cancer

The increasing frequency of general and particularly male cancer coupled with the reduction in male fertility seen worldwide motivated us to seek a potential evolutionary link between these two phenomena, concerning the reproductive transcriptional modules observed in cancer and the expression of cancer-testis antigens (CTA). The phylostratigraphy analysis of the human genome allowed us to link the early evolutionary origin of cancer via the reproductive life cycles of the unicellulars and early multicellulars, potentially driving soma-germ transition, female meiosis, and the parthenogenesis of polyploid giant cancer cells (PGCCs), with the expansion of the CTA multi-families, very late during their evolution. CTA adaptation was aided by retrovirus domestication in the unstable genomes of mammals, for protecting male fertility in stress conditions, particularly that of humans, as compensation for the energy consumption of a large complex brain which also exploited retrotransposition. We found that the early and late evolutionary branches of human cancer are united by the immunity-proto-placental network, which evolved in the Cambrian and shares stress regulators with the finely-tuned sex determination system. We further propose that social stress and endocrine disruption caused by environmental pollution with organic materials, which alter sex determination in male foetuses and further spermatogenesis in adults, bias the development of PGCC-parthenogenetic cancer by default.

Cdc42 Regulates the Expression of Cytoskeleton and Microtubule Network Proteins to Promote Invasion and Metastasis of Progeny Cells Derived from CoCl2-induced Polyploid Giant Cancer Cells

Purpose: Our previous studies have shown that CoCl₂ can induce the formation of polyploid giant cancer cells (PGCCs) and PGCCs could produce progeny cells via asymmetric division. In this study, the molecular mechanism by which PGCCs generate progeny cells with high invasion and migration abilities was explored. Methods: In this study, PGCCs induced by CoCl₂ produced progeny cells via asymmetric division, which was observed dynamically using laser scanning confocal microscopy. Cell cycle in LoVo and Hct116 before and after CoCl₂ treatment was analyzed by flow cytometry. Cell function experiments, co-immunoprecipitation, mass spectrometry analysis, ML141 treatment, western blotting, and siRNA transfection experiments were used to demonstrate that Cdc42/PAK1 was involved in the regulation of cytoskeleton expression. The proliferation, migration, and invasion abilities of PGCCs and progeny cells were compared in PGCCs and progeny cells with and without inhibiting the expression of Cdc42 and PAK1. Results: G2/M phase arrest appeared in CoCl_2-treated LoVo and Hct116 cells. After CoCl₂ treatment, an increased expression of Cdc42 and PAK1 led to a decrease in the expression of stathmin and an increase in the expression of phosphorylated stathmin, which is located in the nucleus of PGCCs and progeny cells. PTPN14 negatively regulates the expression of PAK1 and p38MAPK. Low levels of PTPN14 expression, a downstream regulatory protein of stathmin, endows progeny tumor cells generated by PGCCs with the ability to invade and metastasize. The expression of PKA1α, cathepsin B, and D increased in CoCl₂-treated cells compared with that in the control cells, associated with the infiltration and migration of PGCCs with their progeny cells. Conclusion: CoCl₂-induced overexpression of Cdc42 plays a critical role in increasing the infiltration and migration abilities of PGCCs and progeny cells by regulating cytoskeleton protein expression.

Polyploid giant cancer cells, cytokines and cytomegalovirus in breast cancer progression

BACKGROUND

Breast cancer is the most common cancer among women. Accumulated evidence over the past decades indicates a very high prevalence of human cytomegalovirus (HCMV) in breast cancer. High-risk HCMV strains possess a direct oncogenic effect displayed by cellular stress, polyploid giant cancer cells (PGCCs) generation, stemness, and epithelial-to-mesenchymal transition (EMT) leading to cancer of aggressive phenotype. Breast cancer development and progression have been regulated by several cytokines where the latter can promote cancer cell survival, help in tumor immune evasion, and initiate the EMT process, thereby resulting in invasion, angiogenesis, and breast cancer metastasis. In the present study, we screened cytokines expression in cytomegalovirus-transformed HMECs (CTH cells) cultures infected with HCMV high-risk strains namely, HCMV-DB and BL, as well as breast cancer biopsies, and analyzed the association between cytokines production, PGCCs count, and HCMV presence in vitro and in vivo.

METHODS

In CTH cultures and breast cancer biopsies, HCMV load was quantified by real-time qPCR. PGCCs count in CTH cultures and breast cancer biopsies was identified based on cell morphology and hematoxylin and eosin staining, respectively. CTH supernatants were evaluated for the production of TGF-β, IL-6, IL1-β, and IL-10 by ELISA assays. The above-mentioned cytokines expression was assessed in breast cancer biopsies using reverse transcription-qPCR. The correlation analyses were performed using Pearson correlation test.

RESULTS

The revealed PGCCs/cytokine profile in our in vitro CTH model matched that of the breast cancer biopsies, in vivo. Pronounced cytokine expression and PGCCs count were detected in particularly CTH-DB cultures and basal-like breast cancer biopsies.

CONCLUSIONS

The analysis of cytokine profiles in PGCCs present mostly in basal-like breast cancer biopsies and derived from CTH cells chronically infected with the high-risk HCMV strains might have the potential to provide novel therapies such as cytokine-based immunotherapy which is a promising field in cancer treatments.

The evolutionary cancer gene network theory versus embryogenic hypotheses

The present paper compares the statements of the evolutionary cancer gene-network theory (cancer genome theory) with the statements of embryogenic hypotheses like the embryonic rest hypothesis, the very small embryonic-like stem cells hypothesis, (VSEL), the para-embryonic p-ESC hypothesis, and the PGCC-life cycle hypothesis, including the life code theory. In my opinion, the evolutionary gene network theory is the only theory that can satisfactorily explain the homologies between carcinogenesis, tumorigenesis, metastasis, gametogenesis, and early embryogenesis. From an evolutionary point of view, there is no reason to see the origin of cancer in cells of early embryonic life.

Acetylated-PPARγ expression is regulated by different P53 genotypes associated with the adipogenic differentiation of polyploid giant cancer cells with daughter cells

OBJECTIVE

Polyploid giant cancer cells (PGCCs) with daughter cells express epithelial-mesenchymal transition (EMT)-associated proteins. Highly malignant tumor cells with EMT properties can transdifferentiate into mature tumor cells. In this study, we elucidated the potential for, and underlying mechanism of, adipogenic differentiation of PGCCs with daughter cells (PDCs).

METHODS

Cobalt chloride was used to induce PGCC formation in HEY (wild-type P53) and MDA-MB-231 (mutant P53) cells; these cells were then cultured in adipogenic differentiation medium. Oil red O staining was used to confirm adipogenic differentiation, and the cell cycle was detected with flow cytometry. The expression of adipogenic differentiation-associated proteins and P300 histone acetyltransferase activity were compared before and after adipogenic differentiation. Animal xenograft models were used to confirm the adipogenic differentiation of PDCs.

RESULTS

PDCs transdifferentiated into functional adipocytes. Two different cell cycle distributions were observed in PDCs after adipogenic differentiation. The expression levels of PPARγ, Ace-PPARγ, and Ace-P53 were higher in PDCs after adipogenic differentiation than in cells before adipogenic differentiation. Ace-PPARγ and FABP4 expression increased in HEY cells and decreased in MDA-MB-231 PDCs after p53 knockdown. A485 treatment increased Ace-P53, Ace-PPARγ, and FABP4 expression in HEY PDCs by inhibiting SUMOylation of P53. In MDA-MB-231 PDCs, A485 treatment decreased Ace-P53, Ace-PPARγ, and FABP4 expression. Animal experiments also confirmed the adipogenic differentiation of PDCs.

CONCLUSIONS

Acetylation of P53 and PPARγ plays an important role in the adipogenic differentiation of PDCs.