Current Medicinal Chemistry - Volume 21, Issue 9, 2014

The term “cancer cell reprogramming” is used to define any kind of intervention aimed at transforming cancer cells into terminally differentiated cells. Using this approach, new technologies have been applied with different methods for a more systemic approach to cancer treatment. This review reports on advances of these technologies, including our personal contributions, mainly carried out on endocrine-related cancers. Some of the interventions, aimed at reverting cancer cells into a normal phenotype, are based on the evidence that tumor development is suppressed by the embryonic microenvironment. On the basis of this rationale, experiments have been conducted using stem cell differentiation stage factors (SCDSFs) taken at different stages of development of Zebrafish embryos, oocyte extracts, or naïve human umbilical cord matrix derived stem cells (UMDSCs). SCDSFs induce significant growth inhibition on different tumor cell lines in vitro, likely because of increases in cell cycle regulatory molecules, such as p53 and pRb. Treatment with these factors activates apoptosis and differentiation related to caspase-3. This is achieved via p73 apoptotic-dependent pathway activation with a concurrent normalization of the E-cadherin and beta-catenin ratio. Extracts from prophase amphibian oocytes could reprogram relevant epigenetic alterations in MCF-7 and HCC1954 breast cancer cell lines, while un-engineered (naïve) human UMDSCs attenuated growth of MDA-231 human breast carcinoma cells. A product prepared for human treatments, containing SCDSFs at very low doses, yielded favorable results in breast cancer and in intermediate-advanced hepatocellular carcinoma. Other reprogramming interventions used in the models of breast, prostate and ovarian cancer cell lines are described. Finally, current and future perspectives of this novel technology are discussed and a new hallmark of cancer is suggested: the loss of differentiation of cancer cells.

Neuroendocrine prostate carcinoma (NE-PCa) is a heterogeneous disease. Due to a high prevalence of NE (neuroendocrine) differentiation in patients who receive prolonged androgen deprivation treatment, the real incidence of NE-PCa remains unknown. Similarly, the biological steps from prostate carcinoma (PCa) toward NE differentiation are far less than definitive and, consequently, there is a lack of evidence to support any of the treatments as the “gold standard”. Materials and Methods: A systematic literature search was conducted using the PubMed, Scopus, and Embase databases to identify original articles and review articles regarding NE-PCa . Keywords were “prostate cancer” and “neuroendocrine”. Articles published between 1995 and 2013, were reviewed and selected with the consensus of all of the authors. Results: Fifty-one articles were selected by the authors for the purpose of this review. The principle findings were reported into some subsections: Epidemiology, Biological steps of NE differentiation (with some principle articles on animal and in vitro, since there is very little in the literature on human studies); for the treatment options, we had to expand the search on PubMed to a larger timeframe and selection since very little was specifically found in the first criteria: surgery, radiotherapy, ablative techniques, immunomodulation and epigenetic therapy were then reviewed. A multidisciplinary approach, advocated by many authors, although promising, has failed to demonstrate increased survival rates. Limitations of this review include the lack of a clear definition of NE-PCa and consequently, the lack of strong evidence provided by a large series with long-term follow-up. Conclusions: Supported from this extensive review, we propose it is worthwhile to investigate a new multimodal therapeutic approach to address advanced NE-PCa starting from a debulking (with radical intent) of the disease plus epigenetic therapy with stem cell differentiation stage factors (SCDSFs). In addition immunotherapy can be used to treat the cancer presenting phenotype in association with chemomodulation plus ablative therapies, in case of advanced or recurrent diseases. SCDSFs may be utilized to regulate cancer stem cells and possible new phenotypes could also be associated with ablative therapies. Hormonal deprivation, radiotherapy, chemotherapy, ex vivo vaccines and targeted therapies could also be used and reserved in case of failure

Among the most common human cancers, often only breast and prostate cancers have advantage of hormone dependence. For a long time, this advantage permitted breast cancer to be efficaciously managed in the adjuvant and metastatic settings with low side effects by endocrine therapy. Unfortunately, soon or afterward hormone dependence is lost in most patients. In breast cancer, de novo or acquired hormone resistance is an hot issue and the focus of endless debate. Although a lack of oestrogen receptors (ERs) is considered to be the main reason for de novo hormone resistance, many studies have been conducted and many different mechanisms have been hypothesised to account for acquired hormone resistance. Thus far, hormone resistance appears to be occasionally delayed or avoided in “in vivo” experiments. However, this finding did not have a significant benefit in current clinical practice. The principal aim of this review article is to sum up and update the issue of changing the endocrine dependence of breast cancer. Recent molecular insights extensively elucidating and shedding new light on this very controversial issue are considered. Moreover, based on our recent reports, a new mechanistic interpretation of and a therapeutic approach for overcome hormone resistance are proposed.

Lung neuroendocrine tumors are neoplasms originating from bronchopulmonary neuroendocrine cells, usually Kulchitsky cells, loaded with argentaffin granules. They account for 20-25% of all primitive lung tumors, the most common being the small-cell undifferentiated carcinoma. They include different tumors, from tumors of low-grade malignancy, especially the typical carcinoids, with high survival rates after surgical therapy, to the high-grade malignancy tumors, especially small-cell undifferentiated carcinomas. The latter have very few indications for surgical treatment with a low survival rate, even after multimodal therapy. The aim of this review is to describe the present knowledge and discuss possible new developments in the management of pulmonary neuroendocrine tumors. The authors examine and discuss in particular the role that surgical techniques should have in the treatment of small-cell lung cancer in opposition to a nihilism position that has limited therapies to non-surgical approaches. The critical review of this attitude opens the door to a more aggressive approach. In the meantime the review shows that it might be possible to include the new minimally invasive percutaneous ablative techniques as cryosurgery, thermotherapy and irreversible electroporation within a modern and flexible framework. The authors also present the hypothesis that cancer stem cells (CSC) are at the basis of recurrences of small-cell lung cancer (SCLC) and therefore that the issue is of difficult solution with the conventional oncologic approach considering the chemo-resistance of CSC to drugs. For these reasons an epigenetic therapy based on differentiation factors is proposed alongside the usual surgical and chemo-radiation protocols.

Neoplastic urothelium has the capacity to display enormous plasticity and divergent differentiation. Neuroendocrine tumors arise as a result of such capacity. Neuroendocrine tumors of the bladder represent a limited number of neoplasms characterized by neuroendocrine hormone secretion and a poor outcome. These tumors can be displayed as pure neuroendocrine neoplasms or more frequently as a neuroendocrine counterpart mixed with classical urothelial bladder cell carcinomas, adenocarcinoma, sarcomatoid carcinoma or mixtures of these components. Their heterogeneous character and clinical aggressiveness remain a challenge for clinical, pathological diagnosis and for therapy selection. Several types have been described, although small cell carcinoma represents the major subgroup of neuroendocrine tumors as compared to large cell carcinoma and carcinoid subtypes. In this review, epidemiology, presentation, macroscopic and microscopic features, and clinical prognostic and therapeutic implications of the major subgroups are described. Special focus is given to discuss how immunohistochemistry protein patterns and laboratory determinations may aid to characterize this type of tumors and to improve the clinical management of this highly aggressive type of bladder cancer patients.

Observations on the role of ovarian hormones in breast cancer growth, as well as interest in contraception, stimulated research into the biology of estrogens. The identification of the classical receptors ERα and ERβ and the transmembrane receptor GPER and the resolution of the structure of the ligand bound to its receptor established the principal molecular mechanisms of estrogen action. The presence of estrogen-like compounds in many plants used in traditional medicine or ingested as food ingredients, phytoestrogens, as well as the estrogenic activities of many industrial pollutants and pesticides, xenoestrogens, have prompted investigations into their role in human health. Phyto- and xenoestrogens bind to the estrogen receptors with a lower affinity than the endogenous estrogens and can compete or substitute the hormone. Xenoestrogens, which accumulate in the body throughout life, are believed to increase breast cancer risk, especially in cases of prenatal and prepuberal exposure whereas the role of phytoestrogens is still a matter of debate. At present, the application of phytoestrogens appears to be limited to the treatment of post-menopausal symptoms in women where the production of endogenous estrogens has ceased. In this review we discuss chemistry, structure and classification, estrogen signaling and the consequences of the interactions of estrogens, phytoestrogens and xenoestrogens with their receptors, the complex interactions of endogenous and exogenous ligands, the evaluation of the health risks related to xenoestrogens, and the perspectives toward the synthesis of potent third generation selective estrogen receptor modulators (SERMs).

Reprogramming technologies have been developed to revert somatic differentiated cells into pluripotent stem cells that can be differentiated into different lineages potentially useful in stem cell therapy. Reprogramming methods have been progressively refined to increase their efficiency, to obtain a cell population suitable for differentiation, and to eliminate viral plasmid which could be responsible for many unwanted side-effects when used in personalized medicine. All these methods are aimed to introduce into the cell genes or mRNAs encoding a set of four transcription factors (OCT- 4, SOX-2, KLF-4 and c-MYC) or a set of three lincRNAs (large intragenic non-coding RNAs) acting downstream of the reprogramming transcription factors OCT-4, SOX-2 and NANOG. Translational clinical applications in human pathologies and in developmental, repair and cancer biology have been numerous. Cancer cells can be, at least in principle, reprogrammed into a normal phenotype. This is a recently raised issue, rapidly advancing in many human tumors, especially endocrine-related cancers, such as breast, prostate and ovarian ca. The present review aims to describe basic phenomena observed in reprogramming tumor cells and solid tumors and to discuss their meaning in human hormone-related cancers. We will also discuss the fact that some of the targeted transcription factors are "normally" activated in a number of physiological processes, such as morphogenesis, hypoxia and wound healing, suggesting an in vivo role of reprogramming for development and homeostasis. Finally, we will review concerns and warnings raised for in vivo reprogramming of human tumors and for the use of induced pluripotent stem cells (iPSCs) in human therapy.

Amyloid aggregation is linked to a large number of human disorders, from neurodegenerative diseases as Alzheimer’s disease (AD) or spongiform encephalopathies to non-neuropathic localized diseases as type II diabetes and cataracts. Because the formation of insoluble inclusion bodies (IBs) during recombinant protein production in bacteria has been recently shown to share mechanistic features with amyloid self-assembly, bacteria have emerged as a tool to study amyloid aggregation. Herein we present a fast, simple, inexpensive and quantitative method for the screening of potential anti-aggregating drugs. This method is based on monitoring the changes in the binding of thioflavin-S to intracellular IBs in intact Eschericchia coli cells in the presence of small chemical compounds. This in vivo technique fairly recapitulates previous in vitro data. Here we mainly use the Alzheimer’s related β-amyloid peptide as a model system, but the technique can be easily implemented for screening inhibitors relevant for other conformational diseases simply by changing the recombinant amyloid protein target. Indeed, we show that this methodology can be also applied to the evaluation of inhibitors of the aggregation of tau protein, another amyloidogenic protein with a key role in AD.

In the present work, QSAR model was derived by multiple linear regression method for the prediction of anticancer activity of 18β-glycyrrhetinic acid derivatives against the human breast cancer cell line MCF-7. The QSAR model for anti-proliferative activity against MCF-7 showed high correlation (r2=0.90 and rCV2=0.83) and indicated that chemical descriptors namely, dipole moment (debye), steric energy (kcal/mole), heat of formation (kcal/mole), ionization potential (eV), LogP, LUMO energy (eV) and shape index (basic kappa, order 3) correlate well with activity. The QSAR virtually predicted that active derivatives were first semi-synthesized and characterized on the basis of their 1H and 13C NMR spectroscopic data and then were in-vitro tested against MCF-7 cancer cell line. In particular, octylamide derivative of glycyrrhetinic acid GA-12 has marked cytotoxic activity against MCF-7 similar to that of standard anticancer drug paclitaxel. The biological assays of active derivative selected by virtual screening showed significant experimental activity.