Emerging roles of radioresistance in prostate cancer metastasis and radiation therapy

Prostate cancer therapy outcome prediction: are miRNAs a suitable guide for therapeutic decisions?

BACKGROUND

Radical prostatectomy, radiotherapy, chemotherapy, and androgen-deprivation therapy are among the most common treatment options for different forms of prostate cancer (PCa). However, making therapeutic decisions is difficult due to the lack of reliable prediction markers indicating therapy outcomes in clinical practice. The involvement of miRNAs in all mechanisms of the PCa development and their easy detection characterize them as attractive PCa biomarkers. Although there are extensive data on the role of miRNAs in PCa therapy resistance and sensitivity development, the issues of whether they could be used as a guide for therapy choice and, if so, how we can progress toward this goal, remain unclear. Thus, generalizable reviews and studies which summarize, compare, and analyze data on miRNA involvement in responses to different types of PCa therapies are required.

OBJECTIVES

Data on the involvement of miRNAs in therapy responses, on the role of cross-miRNA expression in different therapies, and on miRNA targets were analyzed in order to determine the miRNA-related factors which can lend perspective to the future development of personalized predictors of PCa sensitivity/resistance to therapies.

MATERIALS AND METHODS

The data available on the miRNAs associated with different PCa therapies (resistance and sensitivity therapies) are summarized and analyzed in this study, including analyses using bioinformatics resources. Special attention was dedicated to the mechanisms of the development of therapy resistance.

RESULTS AND DISCUSSION

A comprehensive combined analysis of the current data revealed a panel of miRNAs that were shown to be most closely associated with the PCa therapy response and were found to regulate the genes involved in PCa development via cell proliferation regulation, epithelial-mesenchymal transition (EMT), apoptosis, cell-cycle progression, angiogenesis, metastasis and invasion regulation, androgen-independent development, and colony formation.

CONCLUSION

The selected miRNA-based panel has the potential to be a guide for therapeutic decision making in the effective treatment of PCa.

Overcoming chemoresistance and radio resistance in prostate cancer: The emergent role of non-coding RNAs

Prostate cancer (PCa) continues to be a major health concern worldwide, with its resistance to chemotherapy and radiation therapy presenting major hurdles in successful treatment. While patients with localized prostate cancer generally have a good survival rate, those with metastatic prostate cancer often face a grim prognosis, even with aggressive treatments using various methods. The high mortality rate in severe cases is largely due to the lack of treatment options that can offer lasting results, especially considering the significant genetic diversity found in tumors at the genomic level. This comprehensive review examines the intricate molecular mechanisms governing resistance in PCa, emphasising the pivotal contributions of non-coding RNAs (ncRNAs). We delve into the diverse roles of microRNAs, long ncRNAs, and other non-coding elements as critical regulators of key cellular processes involved in CR & RR. The review emphasizes the diagnostic potential of ncRNAs as predictive biomarkers for treatment response, offering insights into patient stratification and personalized therapeutic approaches. Additionally, we explore the therapeutic implications of targeting ncRNAs to overcome CR & RR, highlighting innovative strategies to restore treatment sensitivity. By synthesizing current knowledge, this review not only provides a comprehension of the chemical basis of resistance in PCa but also identifies gaps in knowledge, paving the way for future research directions. Ultimately, this exploration of ncRNA perspectives offers a roadmap for advancing precision medicine in PCa, potentially transforming therapeutic paradigms and improving outcomes for patients facing the challenges of treatment resistance.

Evaluation of BMP-2 as a Differentiating and Radiosensitizing Agent for Colorectal Cancer Stem Cells

BACKGROUND

Despite effective clinical responses, a large proportion of patients undergo resistance to radiotherapy. The low response rate to current treatments in different stages of colorectal cancer depends on the prominent role of stem cells in cancer.

OBJECTIVE

In the present study, the role of BMP-2 as an ionizing radiation-sensitive factor in colorectal cancer cells was investigated.

METHODS

A sphere formation assay was used for the enrichment of HCT-116 cancer stem cells (CSCs). The effects of combination therapy (BMP-2+ radiation) on DNA damage response (DDR), proliferation, and apoptosis were evaluated in HCT-116 and CSCs. Gene expressions of CSCs and epithelialmesenchymal transition (EMT) markers were also evaluated.

RESULTS

We found that the sphere formation assay showed a significant increase in the percentage of CSCs. Moreover, expression of CSCs markers, EMT-related genes, and DNA repair proteins significantly decreased in HCT-116 cells compared to the CSCs group after radiation. In addition, BMP-2 promoted the radiosensitivity of HCT-116 cells by decreasing the survival rate of the treated cells at 2, 4, and 6 Gy compared to the control group in HCT-116 cells.

CONCLUSION

Our findings indicated that BMP-2 could affect numerous signaling pathways involved in radioresistance. Therefore, BMP-2 can be considered an appealing therapeutic target for the treatment of radioresistant human colorectal cancer.

Dopamine and cyclic adenosine monophosphate-regulated phosphoprotein with an apparent Mr of 32000 promotes colorectal cancer growth

BACKGROUND

Dopamine and cyclic adenosine monophosphate (cAMP)-regulated phosphoprotein with an apparent Mr of 32000 (DARPP-32) is a protein that is involved in regulating dopamine and cAMP signaling pathways in the brain. However, recent studies have shown that DARPP-32 is also expressed in other tissues, including colorectal cancer (CRC), where its function is not well understood.

AIM

To explore the effect of DARPP-32 on CRC progression.

METHODS

The expression levels of DARPP-32 were assessed in CRC tissues using both quantitative polymerase chain reaction and immunohistochemistry assays. The proliferative capacity of CRC cell lines was evaluated with Cell Counting Kit-8 and 5-ethynyl-2’-deoxyuridine assays, while apoptosis was measured by flow cytometry. The migratory and invasive potential of CRC cell lines were determined using wound healing and transwell chamber assays. In vivo studies involved monitoring the growth rate of xenograft tumors. Finally, the underlying molecular mechanism of DARPP-32 was investigated through RNA-sequencing and western blot analyses.

RESULTS

DARPP-32 was frequently upregulated in CRC and associated with abnormal clinicopathological features in CRC. Overexpression of DARPP-32 was shown to promote cancer cell proliferation, migration, and invasion and reduce apoptosis. DARPP-32 knockdown resulted in the opposite functional effects. Mechanistically, DARPP-32 may regulate the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway in order to carry out its biological function.

CONCLUSION

DARPP-32 promotes CRC progression via the PI3K/AKT signaling pathway.

Circular RNA-0072309 has antitumor influences in Hep3B cell line by targeting microRNA-665

Liver cancer is a malignant tumor that occurs in the liver and has a high mortality rate. We strived to detect the role and mechanism of circRNA-0072309 in liver cancer. Hep3B cell line was transfected with pc-circ and si-circ for viability, colony formation, apoptosis, migration, and invasion tests, which were individually performed by CCK-8, colony formation detection, flow cytometry assay, migration and invasion assays. What is more, the luciferase reporter assay was conducted to determine the target relationship between the circRNA-0072309 and microRNA (miR)-665. The expression of circRNA-0072309 was examined by qRT-PCR. The expression of proteins was examined via western blot. CircRNA-0072309 was lowly expressed in liver cancer tissues and positively associated with 5-year survival rate. The viability, colony formation, invasive and migratory ability were inhibited by abundant circRNA-0072309, which promoted cell apoptosis on the contrary. CircRNA-0072309 knockdown induced opposite effects, but could not affect apoptosis. Overexpressed miR-665 in tumor tissues was targeted and negatively controlled by circRNA-0072309. The PI3K/AKT and Wnt/β-catenin pathways were inhibited by abundant circRNA-0072309. miR-665 overexpression disturbed those effects derived from pc-circ. The circRNA-0072309 had antitumor influences in Hep3B cell line through targeting miR-665 relying on the deactivation of PI3K/AKT and Wnt/β-catenin pathways.

Targeting PI3K/AKT/mTOR Signaling Pathway as a Radiosensitization in Head and Neck Squamous Cell Carcinomas

Globally, there are over half a million new patients with head and neck squamous cell carcinomas (HNSCC) every year. The current therapeutic approaches to HNSCC are surgery and adjuvant radiotherapy. These approaches carry a high incidence of metastasis or recurrence from HNSCC cells' radioresistance. Recent studies have revealed that a combination with radiosensitizers can be used to improve the radioresistance in HNSCC; however, few agents are approved as radiosensitizers. The constitutive activation of phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is a vitally oncogenic type of signaling that promotes tumorigenesis, metastasis, and radiotherapy resistance in HNSCC. Pharmacological targeting of PI3K/AKT/mTOR signaling pathway is considered a promising strategy of radiosensitization in HNSCC. In this review, we summarize the oncogenic significance of PI3K/AKT/mTOR signaling in HNSCC with radiotherapy resistance and highlight the therapeutic potential of small molecule inhibitors against PI3K/AKT/mTOR signaling for the radiosensitization in HNSCC treatment. It provides a mechanistic framework for the development of new drugs for radiosensitization in HNSCC radiotherapy via targeting PI3K/AKT/mTOR signaling pathway.

The Molecular and Cellular Strategies of Glioblastoma and Non-Small-Cell Lung Cancer Cells Conferring Radioresistance

Ionizing radiation (IR) has been shown to play a crucial role in the treatment of glioblastoma (GBM; grade IV) and non-small-cell lung cancer (NSCLC). Nevertheless, recent studies have indicated that radiotherapy can offer only palliation owing to the radioresistance of GBM and NSCLC. Therefore, delineating the major radioresistance mechanisms may provide novel therapeutic approaches to sensitize these diseases to IR and improve patient outcomes. This review provides insights into the molecular and cellular mechanisms underlying GBM and NSCLC radioresistance, where it sheds light on the role played by cancer stem cells (CSCs), as well as discusses comprehensively how the cellular dormancy/non-proliferating state and polyploidy impact on their survival and relapse post-IR exposure.

microRNA-205 in prostate cancer: Overview to clinical translation

Prostate cancer (PrCa) is the most common type of cancer among men in the United States. The metastatic and advanced PrCa develops drug resistance to current regimens which accounts for the poor management. microRNAs (miRNAs) have been well-documented for their diagnostic, prognostic, and therapeutic roles in various human cancers. Recent literature confirmed that microRNA-205 (miR-205) has been established as one of the tumor suppressors in PrCa. miR-205 regulates number of cellular functions, such as proliferation, invasion, migration/metastasis, and apoptosis. It is also evident that miR-205 can serve as a key biomarker in diagnostic, prognostic, and therapy of PrCa. Therefore, in this review, we will provide an overview of tumor suppressive role of miR-205 in PrCa. This work also outlines miR-205's specific role in targeted mechanisms for chemosensitization and radiosensitization in PrCa. A facile approach of delivery paths for successful clinical translation is documented. Together, all these studies provide a novel insight of miR-205 as an adjuvant agent for reducing the widening gaps in clinical outcome of PrCa patients.

CircRNAs in Tumor Radioresistance

Circular RNAs (circRNAs) are endogenous, non-coding RNAs, which are derived from host genes that are present in several species and can be involved in the progression of various diseases. circRNAs’ leading role is to act as RNA sponges. In recent years, the other roles of circRNAs have been discovered, such as regulating transcription and translation, regulating host genes, and even being translated into proteins. As some tumor cells are no longer radiosensitive, tumor radioresistance has since become a challenge in treating tumors. In recent years, circRNAs are differentially expressed in tumor cells and can be used as biological markers of tumors. In addition, circRNAs can regulate the radiosensitivity of tumors. Here, we list the mechanisms of circRNAs in glioma, nasopharyngeal carcinoma, and non-small cell lung cancer; further, these studies also provide new ideas for the purposes of eliminating radioresistance in tumors.

Knockdown of RRM1 in tumor cells promotes radio-/chemotherapy induced ferroptosis by regulating p53 ubiquitination and p21-GPX4 signaling axis

Ferroptosis, a type of regulated cell death brought about by lipid peroxidation, has been discovered to suppress tumor growth. Here, we report that targeting RRM1 promotes ferroptosis and affects sensitivity to radiation and chemotherapeutics in cancer cells. In vitro experiments demonstrate that RRM1 increases the accumulation of cellular reactive oxygen species (ROS) and lipid peroxidation by disrupting the activity and expression of the antioxidant enzyme GPX4. Further studies reveal the downstream mechanisms of RRM1, which can regulate the deubiquitinating enzyme USP11 and ubiquitinating enzyme MDM2 to affect the ubiquitination modification of p53. Unstable p53 then inhibited the activity and expression of GPX4 by restraining the p21 protein. Furthermore, our data reveal that targeting RRM1 also increases radiation-induced DNA damage and apoptotic signaling and causes crosstalk between ferroptosis and apoptosis. On the basis of our collective findings, we propose that RRM1 is an essential negative mediator of radiosensitivity through regulating ferroptosis, which could serve as a potential target to inhibit the tumor's antioxidant system and enhance the efficiency of radio/chemotherapy.

Ginsenoside Rh3 Inhibits Lung Cancer Metastasis by Targeting Extracellular Signal-Regulated Kinase: A Network Pharmacology Study

Lung cancer has a high mortality rate and is very common. One of the main reasons for the poor prognosis of patients with lung cancer is the high incidence of metastasis. Ginsenoside Rh3, a rare ginsenoside extracted from Panax notoginseng, exhibits excellent anti-inflammatory and anti-tumor effects. Nonetheless, the inhibitory potential of Rh3 against lung cancer remains unknown. The target genes of Rh3 were screened by the PharmMapper database; the proliferation of lung cancer cells was detected by MTT assay; the migration and invasion of cells were detected by the Transwell method; and the expression of extracellular signal-regulated kinase (ERK) and EMT-related proteins in vivo and in vitro were detected by Western blotting. In addition, we established a lung metastasis model in nude mice using A549 cells to assess the effect of Rh3 on NSCLC tumor metastasis in vivo. Our findings suggest that Rh3 significantly inhibited lung cancer metastasis both in vivo and in vitro. It was determined by flow cytometry analysis that Rh3 notably inhibited cell proliferation by blocking the G1 phase. In addition, Rh3 inhibited metastasis in lung cancer cells and regulated the expression of metastasis-related proteins under hypoxia. Mechanistic studies suggested that Rh3 targeted ERK to inhibit lung cancer metastasis. The ERK inhibitor U0126 or siRNA-mediated knockdown of ERK had an enhanced effect on Rh3’s ability to inhibit lung cancer metastasis. The studies revealed that the inhibitory effect of Rh3 on the metastatic ability of lung cancer cells may be supported by ERK-related signaling pathways.

The Role of Microbiota in the Immunopathogenesis of Endometrial Cancer

The female reproductive tract hosts a specific microbiome, which plays a crucial role in sustaining equilibrium and good health. In the majority of reproductive women, the microbiota (all bacteria, viruses, fungi, and other single-celled organisms within the human body) of the vaginal and cervical microenvironment are dominated by Lactobacillus species, which benefit the host through symbiotic relationships, in comparison to the uterus, fallopian tubes, and ovaries, which may contain a low-biomass microbiome with a diverse mixture of microorganisms. Although disruption to the balance of the microbiota develops, the altered immune and metabolic signaling may cause an impact on diseases such as cancer. These pathophysiological modifications in the gut–uterus axis may spark gynecological cancers. New information displays that gynecological and gastrointestinal tract dysbiosis (disruption of the microbiota homeostasis) can play an active role in the advancement and metastasis of gynecological neoplasms, such as cervical, endometrial, and ovarian cancers. Understanding the relationship between microbiota and endometrial cancer is critical for prognosis, diagnosis, prevention, and the development of innovative treatments. Identifying a specific microbiome may become an effective method for characterization of the specific microbiota involved in endometrial carcinogenesis. The aim of this study was to summarize the current state of knowledge that describes the correlation of microbiota with endometrial cancer with regard to the formation of immunological pathologies.

Targeting Epithelial-to-Mesenchymal Transition in Radioresistance: Crosslinked Mechanisms and Strategies

Radiotherapy exerts a crucial role in curing cancer, however, its treatment efficiency is mostly limited due to the presence of radioresistance. Epithelial-to-mesenchymal transition (EMT) is a biological process that endows the cancer cells with invasive and metastatic properties, as well as radioresistance. Many potential mechanisms of EMT-related radioresistance being reported have broaden our cognition, and hint us the importance of an overall understanding of the relationship between EMT and radioresistance. This review focuses on the recent progresses involved in EMT-related mechanisms in regulating radioresistance, irradiation-mediated EMT program, and the intervention strategies to increase tumor radiosensitivity, in order to improve radiotherapy efficiency and clinical outcomes of cancer patients.

Re-establishing the comprehension of phytomedicine and nanomedicine in inflammation-mediated cancer signaling

Recent mounting evidence has revealed extensive genetic heterogeneity within tumors that drive phenotypic variation affecting key cancer pathways, making cancer treatment extremely challenging. Diverse cancer types display resistance to treatment and show patterns of relapse following therapy. Therefore, efforts are required to address tumor heterogeneity by developing a broad-spectrum therapeutic approach that combines targeted therapies. Inflammation has been progressively documented as a vital factor in tumor advancement and has consequences in epigenetic variations that support tumor instigation, encouraging all the tumorigenesis phases. Increased DNA damage, disrupted DNA repair mechanisms, cellular proliferation, apoptosis, angiogenesis, and its incursion are a few pro-cancerous outcomes of chronic inflammation. A clear understanding of the cellular and molecular signaling mechanisms of tumor-endorsing inflammation is necessary for further expansion of anti-cancer therapeutics targeting the crosstalk between tumor development and inflammatory processes. Multiple inflammatory signaling pathways, such as the NF-κB signaling pathway, JAK-STAT signaling pathway, MAPK signaling, PI3K/AKT/mTOR signaling, Wnt signaling cascade, and TGF-β/Smad signaling, have been found to regulate inflammation, which can be modulated using various factors such as small molecule inhibitors, phytochemicals, recombinant cytokines, and nanoparticles in conjugation to phytochemicals to treat cancer. Researchers have identified multiple targets to specifically alter inflammation in cancer therapy to restrict malignant progression and improve the efficacy of cancer therapy. siRNA-and shRNA-loaded nanoparticles have been observed to downregulate STAT3 signaling pathways and have been employed in studies to target tumor malignancies. This review highlights the pathways involved in the interaction between tumor advancement and inflammatory progression, along with the novel approaches of nanotechnology-based drug delivery systems currently used to target inflammatory signaling pathways to combat cancer.

The Evolution of Pharmacological Activities Bouea macrophylla Griffith In Vivo and In Vitro Study: A Review

Bouea macrophylla Griffith (B. macrophylla) is one of the many herbal plants found in Asia, and its fruit is plum mango. This plant is rich in secondary metabolites, including flavonoids, tannins, polyphenolic compounds, and many others. Due to its bioactive components, plum mango has powerful antioxidants that have therapeutic benefits for many common ailments, including cardiovascular disease, diabetes, and cancer. This review describes the evolution of plum mango’s phytochemical properties and pharmacological activities including in vitro and in vivo studies. The pharmacological activities of B. macrophylla Griffith reviewed in this article are antioxidant, anticancer, antihyperglycemic, antimicrobial, and antiphotoaging. Each of these pharmacological activities described and studied the possible cellular and molecular mechanisms of action. Interestingly, plum mango seeds show good pharmacological activity where the seed is the part of the plant that is a waste product. This can be an advantage because of its economic value as a herbal medicine. Overall, the findings described in this review aim to allow this plant to be explored and utilized more widely, especially as a new drug discovery.

Circular RNAs in prostate cancer: Biogenesis,biological functions, and clinical significance

Circular RNAs (circRNAs) are covalently closed RNA molecules that play important regulatory roles in various tumors. Prostate cancer (PCa) is one of the most common malignant tumors in the world, with high morbidity and mortality. In recent years, more and more circRNAs have been found to be abnormally expressed and involved in the occurrence and development of PCa, including cell proliferation, apoptosis, invasion, migration, metastasis, chemotherapy resistance, and radiotherapy resistance. Most of the circRNAs regulate biological behaviors of cancer through a competitive endogenous RNA (ceRNA) regulatory mechanism, and some can exert their functions by binding to proteins. circRNAs are also associated with many clinicopathological features of PCa, including tumor grade, lymph node metastasis, and distant metastasis. In addition, circRNAs are potential diagnostic and prognostic biomarkers for PCa. Considering their critical regulatory roles in the progression of PCa, circRNAs would be the potential therapeutic targets. In this paper, the current research status of circRNAs in PCa is briefly reviewed.

Decreased mitochondrial membrane potential is an indicator of radioresistant cancer cells

AIMS

To overcome radioresistant cancer cells, clinically relevant radioresistant (CRR) cells were established. To maintain their radioresistance, CRR cells were exposed 2 Gy/day of X-rays daily (maintenance irradiation: MI). To understand whether the radioresistance induced by X-rays was reversible or irreversible, the difference between CRR cells and those without MI for a year (CRR-NoIR cells) was investigated by the mitochondrial function as an index.

MAIN METHODS

Radiation sensitivity was determined by modified high density survival assay. Mitochondrial membrane potential (Δψm) was determined by 5,5',6,6'-tetrachloro-1,1', tetraethylbenzimidazolocarbo-cyanine iodide (JC-1) staining. Rapid Glucose-Galactose assay was performed to determine the shift in their energy metabolism from aerobic glycolysis to oxidative phosphorylation in CRR cells. Involvement of prohibitin-1 (PHB1) in Δψm was evaluated by knockdown of PHB1 gene followed by real-time PCR.

KEY FINDINGS

CRR cells that exhibited resistant to 2 Gy/day X-ray lost their radioresistance after more than one year of culture without MI for a year. In addition, CRR cells lost their radioresistance when the mitochondria were activated by galactose. Furthermore, Δψm were increased and PHB1 expression was down-regulated, in the process of losing their radioresistance.

SIGNIFICANCE

Our finding reveled that tune regulation of mitochondrial function is implicated in radioresistance phenotype of cancer cells. Moreover, as our findings indicate, though further studies are required to clarify the precise mechanisms underlying cancer cell radioresistance, radioresistant cells induced by irradiation and cancer stem cells that are originally radioresistant should be considered separately, the radioresistance of CRR cells is reversible.

Abiraterone In Vitro Is Superior to Enzalutamide in Response to Ionizing Radiation

Abiraterone acetate and Enzalutamide are novel anti-androgens that are key treatments to improve both progression-free survival and overall survival in patients with metastatic castration-resistant prostate cancer. In this study, we aimed to determine whether combinations of AR inhibitors with radiation are additive or synergistic, and investigated the underlying mechanisms governing this. This study also aimed to compare and investigate a biological rationale for the selection of Abiraterone versus Enzalutamide in combination with radiotherapy as currently selection is based on consideration of side effect profiles and clinical experience. We report that AR suppression with Enzalutamide produces a synergistic effect only in AR-sensitive prostate models. In contrast, Abiraterone displays synergistic effects in combination with radiation regardless of AR status, alluding to potential alternative mechanisms of action. The underlying mechanisms governing this AR-based synergy are based on the reduction of key AR linked DNA repair pathways such as NHEJ and HR, with changes in HR potentially the result of changes in cell cycle distribution, with these reductions ultimately resulting in increased cell death. These changes were also shown to be conserved in combination with radiation, with AR suppression 24 hours before radiation leading to the most significant differences. Comparison between Abiraterone and Enzalutamide highlighted Abiraterone from a mechanistic standpoint as being superior to Abiraterone for all endpoints measured. Therefore, this provides a potential rationale for the selection of Abiraterone over Enzalutamide.

C19orf10 promotes malignant behaviors of human bladder carcinoma cells via regulating the PI3K/AKT and Wnt/β-catenin pathways

Background: Chromosome 19 open reading frame 10 (C19orf10) is a myocardial repair mediator overexpressed in hepatocellular carcinoma. However, its function and clinical value in bladder cancer (BC) have not been reported. This study aimed to investigate the role of C19orf10 in BC progression and explore underlying mechanisms.

Methods: C19orf10 expression in BC tissues and human BC cell lines was assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. The correlation between the C19orf10 protein levels determined by immunohistochemical staining and the clinicopathological characteristics of 192 BC patients was evaluated. BC cell lines SW780, J82 and UMUC-3 were transfected with small interfering RNA (siRNA) targeting C19orf10 or plasmids overexpressing C19orf10. Cell proliferation, migration and invasion were measured by Cell Counting Kit-8, Colony formation, EdU incorporation and Transwell assays. The effect of small hairpin RNA (shRNA)-mediated stable C19orf10 knockdown on tumor formation was assessed in a xenograft mouse model. The expressions of epithelial-mesenchymal transition (EMT) markers, PI3K/AKT and Wnt/β-catenin signaling pathways-related molecules were determined by western blot assay.

Results: C19orf10 was significantly upregulated in the BC tissues and a panel of human BC cell lines. High expression of C19orf10 was positively associated with malignant behaviors in BC. C19orf10 knockdown inhibited cell proliferation, migration, and invasion in SW780 and J82 cells, while C19orf10 overexpression in UMUC-3 cells resulted in opposite effects. In addition, C19orf10 silence in SW780 cells suppressed tumor growth in xenograft mice. Moreover, C19orf10 promotes the malignant behaviors and EMT of human bladder carcinoma cells via regulating the PI3K/AKT and Wnt/β-catenin pathways.

Conclusion: C19orf10 is overexpressed in BC and functions as an oncogenic driver that promotes cell proliferation and metastasis, and induces EMT of BC cells via mechanisms involving activation of the PI3K/AKT and Wnt/β-catenin pathways. This study provides valuable insight on targeting C19orf10 for BC treatment.

Radiotherapy programs neutrophils to an antitumor phenotype by inducing mesenchymal-epithelial transition

Background

Neutrophils can play a pro-tumor or anti-tumor role depending on the tumor microenvironment. The effects of concurrent treatment with granulocyte colony-stimulating factor (G-CSF) and radiotherapy (RT) on neutrophils have not yet to be described.

Methods

Hypofractionated radiation of 8 Gy ×3 fractions was administered with or without recombinant G-CSF to Lewis lung carcinoma tumor-bearing C57BL/6 model mice. The activation status of cytotoxic T cells in the mice was measured, along with the levels of tumor-associated neutrophils, cytotoxic T cells, and Treg cells. Tumor growth, survival, cytokine expression, and signaling pathways underlying anti-tumor effects of tumor-associated neutrophils after treatment were also studied. To ascertain the effects of concurrent RT and G-CSF on tumor-associated neutrophils, neutrophil depletion was performed.

Results

RT affected early neutrophil infiltration, which is the first-line immune response. Subsequently, enhanced accumulation of lymphocytes, particularly CD8 cytotoxic T cells, was observed. Notably, lymphocytic infiltration was inhibited by neutrophil depletion but enhanced by G-CSF treatment. RT generated persistent DNA damage, as evidenced by an accumulation of phosphorylation of histone H2AX (γH2AX), and subsequently triggered inflammatory chemokine secretion. The chemokines CXCL1, CXCL2, and CCL5 were upregulated in both radiation-treated cells and the corresponding supernatants. Neutrophils that were newly recruited after RT improved radiosensitivity by inhibiting epithelial-mesenchymal transition via the reactive oxygen species-mediated PI3K/Akt/Snail signaling pathway, and G-CSF treatment enhanced this effect.

Conclusions

The results of this study suggest that RT activates neutrophil recruitment and polarizes newly recruited neutrophils toward an antitumor phenotype, which is enhanced by the concurrent administration of G-CSF. Mesenchymal-epithelial transition induced by reactive oxygen species accumulation plays a major role in this process. Thus, the polarization of tumor-associated neutrophils might play a role in future cancer immunotherapies.

Longitudinal CTCs gene expression analysis on metastatic castration-resistant prostate cancer patients treated with docetaxel reveals new potential prognosis markers

CTCs have extensively been used for the monitoring and characterization of metastatic prostate cancer, but their application in the clinic is still very scarce. Besides, the resistance mechanisms linked to prostate cancer treatment remain unclear. Liquid biopsies represent the most promising alternative due to the complexity of biopsying bone metastasis and the duration of the disease. We performed a prospective longitudinal study in CTCs from 20 castration-resistant prostate cancer patients treated with docetaxel. For that, we used CellSearch® technology and a custom gene expression panel with qRT-PCR using a CTCs negative enrichment approach. We found that CTCs showed a hybrid phenotype during the disease, where epithelial features were associated with the presence of ≥ 5 CTCs/7.5 mL of blood, while high relative expression of the gene MYCL was observed preferentially in the set of samples with < 5 CTCs/7.5 mL of blood. At baseline, patients whose CTCs had stem or hybrid features showed a later progression. After 1 cycle of docetaxel, high relative expression of ZEB1 indicated worse outcome, while KRT19 and KLK3 high expression could predisposed the patients to a worse prognosis at clinical progression. In the present work we describe biomarkers with clinical relevance for the prediction of early response or resistance in castration-resistant prostate cancer patients. Besides, we question the utility of targeted isolated CTCs and the use of a limited number of markers to define the CTCs population.

miRNAs and radiotherapy response in prostate cancer

BACKGROUND

Gaining insight into microRNAs (miRNAs) and genes that regulate the therapeutic response of cancer diseases in general and prostate cancer (PCa) in particular is an important issue in current molecular biomedicine and allows the discovery of predictive miRNA targets.

OBJECTIVES

The aim of this study was to analyze the available data on the influence of radiotherapy (RT) on miRNA expression and on miRNA involved in radiotherapy response in PCa.

MATERIALS AND METHODS

The data used in this review were extracted from research papers and the DIANA, STRING, and other databases with a special focus on the mechanisms of radiotherapy PCa response and the miRNA involved and associated genes.

RESULTS AND DISCUSSION

A search for miRNA prognostic and therapeutic effectiveness markers should rely on both the data of recent experimental studies on the influence of RT on miRNA expression and miRNAs involved in regulation of radiosensitivity in PCa and on bioinformatics resources. miRNA panels and genes targeted by them and involved in radioresponse regulation highlighted by meta-analysis and cross-analysis of the data in the present review have.

CONCLUSION

Selected miRNA and gene panel has good potential as prognostic and radiotherapy effectiveness markers for PCa and, moreover, as radiotherapy effectiveness markers in other types of cancer, as the proposed model is not specific to PCa, which opens up opportunities for the development of a universal diagnostic system (or several intersecting systems) for oncology radiotherapy in general.

Overcoming epithelial-mesenchymal transition-mediated drug resistance with monensin-based combined therapy in non-small cell lung cancer

BACKGROUND

The epithelial-mesenchymal transition (EMT) is a key process in tumor progression and metastasis and is also associated with drug resistance. Thus, controlling EMT status is a research of interest to conquer the malignant tumors.

MATERIALS AND METHODS

A drug repositioning analysis of transcriptomic data from a public cell line database identified monensin, a widely used in veterinary medicine, as a candidate EMT inhibitor that suppresses the conversion of the EMT phenotype. Using TGF-β-induced EMT cell line models, the effects of monensin on the EMT status and EMT-mediated drug resistance were assessed.

RESULTS

TGF-β treatment induced EMT in non-small cell lung cancer (NSCLC) cell lines and the EGFR-mutant NSCLC cell lines with TGF-β-induced EMT acquired resistance to EGFR-tyrosine kinase inhibitor. The addition of monensin effectively suppressed the TGF-β-induced-EMT conversion, and restored the growth inhibition and the induction of apoptosis by the EGFR-tyrosine kinase inhibitor.

CONCLUSION

Our data suggested that combined therapy with monensin might be a useful strategy for preventing EMT-mediated acquired drug resistance.

Knockdown of Circ_CCNB2 Sensitizes Prostate Cancer to Radiation Through Repressing Autophagy by the miR-30b-5p/KIF18A Axis

Background: Circular RNAs (circRNAs) have recently emerged as crucial regulatory molecules in prostate cancer (PCa), but few researches focus on the effects of circRNAs on PCa radiosensitivity. The issue will be addressed in this study using circRNA Cyclin B2 (circ_CCNB2) as an object. Materials and Methods: All RNA and protein levels were severally examined using quantitative real-time polymerase chain reaction and Western blot. Colony formation assay and flow cytometry were implemented for detecting cell colony capacity and apoptotic cells, respectively. Cellular migration and invasion abilities were evaluated by transwell assay. The combination between potential target molecules was analyzed by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. The effect of circ_CCNB2 on PCa radiosensitivity in vivo was explored using xenograft models in mice. Results: Circ_CCNB2 was upregulated in irradiation-resistant PCa tissues and cells. Circ_CCNB2 knockdown had promoted effect on the radiosensitivity of irradiation-resistant PCa cells by inhibiting autophagy. Besides, circ_CCNB2 could directly sponge miR-30b-5p, and the promotion of circ_CCNB2 knockdown on PCa radiosensitivity was achieved by elevating miR-30b-5p. MiR-30b-5p enhanced the radiosensitivity of irradiation-resistant PCa cells through repressing the expression of its target kinesin family member 18A (KIF18A). Furthermore, circ_CCNB2 regulated the KIF18A level through targeting miR-30b-5p. Circ_CCNB2 downregulation facilitated PCa radiosensitivity in vivo through inhibiting autophagy by miR-30b-5p/KIF18A. Conclusions: In this study, knockdown of circ_CCNB2 was shown to promote PCa radiosensitivity through autophagy repression by miR-30b-5p/KIF18A axis, developing a molecular resistance mechanism of PCa radiotherapy and a feasible strategy to increase radiosensitivity.

The anticancer activities of Vernonia amygdalina Delile. Leaves on 4T1 breast cancer cells through phosphoinositide 3-kinase (PI3K) pathway

Vernonia amygdalina Delile (Asteraceae) is used in traditional medicine to treat diabetes mellitus, and some research provides its activity to treat breast cancer. The aim of this study is to assess the anticancer activity of Vernonia amygdalina Delile leaves fractions on 4T1 breast cancer cells. Analysis of phytochemical compounds were carried out with LC-MS/MS. Cytotoxic activity was determined using the MTT method in the 4T1 cell line. Apoptosis, the cell cycle, and PI3K and mTOR profiles were analyzed with flow cytometry. The phytochemicals found were diterpene (ingenol-3-angelate) and some phenolics (chlorogenic acid and 4-methoxycinnamic acid), flavonoids (apigetrin, apigenin, luteolin, diosmetin, baicalin, rhoifolin, and scutellarin), and coumarines (7-hydroxycoumarine, 4-methylumbelliferone, and 4-methylumbelliferyl glucuronide). The results of the MTT assay showed that the IC₅₀ values n-hexane fraction, ethylacetate fraction (EAF), and ethanol fractions were 1,860.54 ± 93.11, 25.04 ± 0.36, and 1,940.84 ± 96.37 μg/mL, respectively. EAF induced early and late apoptosis, inhibited cell cycle progression on the G₂/M phase, and inhibited PI3K and mTOR expression. The EAF of Vernonia amygdalina Delile leaves showed anticancer activity on 4T1 breast cancer cells through induction of apoptosis, enhanced cell accumulation on G₂/M phases in the cell cycle, and inhibited expression of PI3K and mTOR.

Hydroxychloroquine-loaded hollow mesoporous silica nanoparticles for enhanced autophagy inhibition and radiation therapy

Radiotherapy (RT) is a major modality for cancer treatment, along with surgery and chemotherapy. Despite its therapeutic effect, the recurrence and metastasis of tumors due to the acquired resistance of cancer cells to RT remain significant clinical problems. Therefore, it is imperative to overcome radioresistance and improve radiosensitivity in cancer patients. Here, we synthesized hydroxychloroquine (HCQ)-loaded hollow mesoporous silica nanoparticles (HMSNs) to enable effective inhibition of radiation-induced cytoprotective autophagy and enhance the therapeutic efficacy of RT. HCQ-HMSN-treated HCT116 colon cancer cells showed a 200-fold higher intracellular uptake of HCQ than that of free HCQ-treated cells, thereby effectively inhibiting the radiation-induced autophagy of cancer cells. In vivo imaging and therapy studies of a tumor xenograft model showed preferential accumulation of HCQ-HMSNs in tumor tissues and significant enhancement of RT by inhibiting autophagy in the tumor sites. Histopathology analyses of major organs, blood chemistry profiles, and changes in body weights of mice confirmed the good biocompatibility of HCQ-HMSNs.

Moringa oleifera methanolic leaves extract induces apoptosis and G0/G1 cell cycle arrest via downregulation of Hedgehog Signaling Pathway in human prostate PC-3 cancer cells

The inadequacy of effective treatment approaches for prostate cancer enlightens the crucial necessity for the search and emergence of novel and multitasking anticancer substances. Several experimental studies suggested the role of natural compounds in prostate cancer growth inhibition by Hedgehog signaling modulation. In the current study, we suggested the anticancer and apoptosis inducing effects of Moringa oleifera (M. oleifera) were linked to downregulation of Hedgehog pathway in PC-3 prostate cancer cells. We found that M. oleifera leaves methanolic extract exhibited significant anticancerous potential by inducing ROS-mediated apoptosis and activation of caspase-3 activity in prostate cancer. We also observed a dose-dependent G0/G1 cell cycle arrest as well as significant alteration in mRNA expression of apoptosis related and Hedgehog signaling pathway genes by M. oleifera extract treatment. Altogether, these experimental findings demonstrated that M. oleifera may exert antiproliferative apoptosis inducing effects by Hedgehog signaling pathway downregulation. PRACTICAL APPLICATIONS: Moringa oleifera plant, a rich nutrional source, has extensive range of pharmacological applications including antioxidant, anti-inflammatory, and anticancer activity. To best of our knowledge, this could be the first intensive report which presented the inhibitory potential of M. oleifera leaves extract against PC-3 prostate cancer cells via targeting key molecules of Hedgehog signaling. Decreased mRNA expression of GLI1 transcription factor and SMO protein of Hedgehog signaling pathway may be involved in antiproliferative effects of M. oleifera leaves extract against prostate cancer cells. Our study suggested that M. oleifera supplementation might be beneficial for the development and improvement of targeted therapeutic strategies in prostate cancer cells.

SPOP Deregulation Improves the Radiation Response of Prostate Cancer Models by Impairing DNA Damage Repair

Speckle-type POZ (pox virus and zinc finger protein) protein (SPOP) is the most commonly mutated gene in prostate cancer (PCa). Recent evidence reports a role of SPOP in DNA damage response (DDR), indicating a possible impact of SPOP deregulation on PCa radiosensitivity. This study aimed to define the role of SPOP deregulation (by gene mutation or knockdown) as a radiosensitizing factor in PCa preclinical models. To express WT or mutant (Y87N, K129E and F133V) SPOP, DU145 and PC-3 cells were transfected with pMCV6 vectors. Sensitivity profiles were assessed using clonogenic assay and immunofluorescent staining of γH2AX and RAD51 foci. SCID xenografts were treated with 5 Gy single dose irradiation using an image-guided small animal irradiator. siRNA and miRNA mimics were used to silence SPOP or express the SPOP negative regulator miR-145, respectively. SPOP deregulation, by either gene mutation or knockdown, consistently enhanced the radiation response of PCa models by impairing DDR, as indicated by transcriptome analysis and functionally confirmed by decreased RAD51 foci. SPOP silencing also resulted in a significant downregulation of RAD51 and CHK1 expression, consistent with the impairment of homologous recombination. Our results indicate that SPOP deregulation plays a radiosensitizing role in PCa by impairing DDR via downregulation of RAD51 and CHK1.

Novel PI3K/Akt/mTOR pathway inhibitors plus radiotherapy: Strategy for non-small cell lung cancer with mutant RAS gene

Non-small cell lung cancer (NSCLC) with RAS -mutant gene has been the most difficult obstacle to overcome. Over 25% of muted lung adenocarcinomas have RAS mutation. The prognosis of NSCLC patients with RAS-mutant genes is always poor because there is no effective drug to suppress RAS-mutant genes. NSCLC patients with RAS-mutant usually develop resistance to radiotherapy and chemotherapy, which in some cases leads to a 5-10% survival rate for non-small cell lung cancer (NSCLC). As little clinical symptom of NSCLC was presented at its early stages, thus it always brings in disappointing treatment outcome. Currently, NSCLC presents the highest morbidity and mortality all over the world. The combination of PI3K/AKT/mTOR pathway inhibitors with radiotherapy is a novel strategy to improve radiosensitivity and therapeutic outcome of NSCLC with a RAS-mutant gene. There have been many preclinical studies and clinical trials on the effect of PI3K/AKT/mTOR pathway inhibitors combined with radiotherapy in NSCLC with a RAS-mutant gene have been reported in the past years. This review provides current knowledge of the combination of PI3K/Akt/mTOR pathway inhibitors with radiotherapy, which prove to be a significant improvement for the treatment of NSCLC patients with RAS mutations and will benefit NSCLC patients with RAS mutations.

Ras and Wnt Interaction Contribute in Prostate Cancer Bone Metastasis

Prostate cancer (PCa) is one of the most prevalent and malignant cancer types in men, which causes more than three-hundred thousand cancer death each year. At late stage of PCa progression, bone marrow is the most often metastatic site that constitutes almost 70% of metastatic cases of the PCa population. However, the characteristic for the osteo-philic property of PCa is still puzzling. Recent studies reported that the Wnt and Ras signaling pathways are pivotal in bone metastasis and that take parts in different cytological changes, but their crosstalk is not well studied. In this review, we focused on interactions between the Wnt and Ras signaling pathways during each stage of bone metastasis and present the fate of those interactions. This review contributes insights that can guide other researchers by unveiling more details with regard to bone metastasis and might also help in finding potential therapeutic regimens for preventing PCa bone metastasis.

The role of epithelial-mesenchymal transition in regulating radioresistance

Cancer patients with different stages can benefit from radiotherapy, but there are still limited due to inherent or acquired radioresistance. The epithelial-mesenchymal transition (EMT) is a complex biological process that is implicated in malignant characteristics of cancer, such as radioresistance. Although the possible mechanisms of EMT-dependent radioresistance are being extensively studied, there is a lack of a clear picture of the overall signaling of EMT-mediated radioresistance. In this review, we highlight the role and possible molecular mechanisms of EMT in cancer radioresistance, in particular to EMT-associated signaling pathway, EMT-inducing transcription factors (EMT-TFs), EMT-related non-coding RNAs. The knowledge of EMT-associated mechanisms of radioresistance will offer more potent therapy targets to improve the radiotherapy responses.

RETRACTED: Endogenous production of C-C motif chemokine ligand 2 by nasopharyngeal carcinoma cells drives radioresistance-associated metastasis

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Following the publication of the above article, the Editor was notified by a concerned reader that the authors supplied duplicated images. Specifically, overlap in Figures 1C, 4A, 4B, 4D, and 5C. These concerns were also reported at PubPeer https://pubpeer.com/publications/CAC11E726E1C3E261A1F8BB90FF173. After review, the Editor found that duplication did occur and therefore the decision was made to retract the article. After re-examination of the entire paper, raw data and lab records, the authors have found that “pictures between different experiments were carelessly mixed. We want to apologize for all the inconvenience it caused to the editorial board, and to all our peers and to all the readers of our paper.”

Hypoxia induced microRNA-301b-3p overexpression promotes proliferation, migration and invasion of prostate cancer cells by targeting LRP1B

Prostate cancer is a high burden on society worldwide due to its high morbidity and mortality. Growing evidence has implicated microRNAs (miRNAs or miRs) in the occurrence and progression of prostate cancer. The present study was conducted with main emphasis put on the possible effect of hypoxia-induced miR-301b-3p on prostate cancer by targeting low-density lipoprotein receptor-related protein 1B (LRP1B). Firstly, the differentially expressed genes were identified by conducting microarray-based gene expression profiling of prostate cancer. Next, the expression of miR-301b-3p in prostate cancer cells was examined in cells treated with 1% oxygen or dimethyloxalylglycine (DMOG), and the cell line with the highest miR-301b-3p expression was selected for subsequent experiments. Subsequently, the target relationship between miR-301b-3p and LRP1B was identified. The effect of miR-301b-3p and LRP1B on cell proliferation, migration and invasion as well as tumorigenicity of transfected cells was examined using the gain- and loss-of-function approaches. Hypoxia induced miR-301b-3p was highly expressed while LRP1B was poorly expressed in prostate cancer. Moreover, miR-301b-3p could down-regulate LRP1B by interacting with LRP1B, which acted to promote the proliferation, migration and invasion abilities of prostate cancer cells in addition to tumor growth in vivo. In addition, up-regulation of LRP1B can reverse the promoting effect of miR-301b-3p on the aforementioned factors. Collectively, up-regulation of miR-301b-3p induced by hypoxia could potentially accelerate proliferation, migration and invasion of prostate cancer cells via the inhibitory effect on LRP1B expression, highlighting that miR-301b-3p may be instrumental for the therapeutic targeting of prostate cancer.

Network-based analysis of prostate cancer cell lines reveals novel marker gene candidates associated with radioresistance and patient relapse

Radiation therapy is an important and effective treatment option for prostate cancer, but high-risk patients are prone to relapse due to radioresistance of cancer cells. Molecular mechanisms that contribute to radioresistance are not fully understood. Novel computational strategies are needed to identify radioresistance driver genes from hundreds of gene copy number alterations. We developed a network-based approach based on lasso regression in combination with network propagation for the analysis of prostate cancer cell lines with acquired radioresistance to identify clinically relevant marker genes associated with radioresistance in prostate cancer patients. We analyzed established radioresistant cell lines of the prostate cancer cell lines DU145 and LNCaP and compared their gene copy number and expression profiles to their radiosensitive parental cells. We found that radioresistant DU145 showed much more gene copy number alterations than LNCaP and their gene expression profiles were highly cell line specific. We learned a genome-wide prostate cancer-specific gene regulatory network and quantified impacts of differentially expressed genes with directly underlying copy number alterations on known radioresistance marker genes. This revealed several potential driver candidates involved in the regulation of cancer-relevant processes. Importantly, we found that ten driver candidates from DU145 (ADAMTS9, AKR1B10, CXXC5, FST, FOXL1, GRPR, ITGA2, SOX17, STARD4, VGF) and four from LNCaP (FHL5, LYPLAL1, PAK7, TDRD6) were able to distinguish irradiated prostate cancer patients into early and late relapse groups. Moreover, in-depth in vitro validations for VGF (Neurosecretory protein VGF) showed that siRNA-mediated gene silencing increased the radiosensitivity of DU145 and LNCaP cells. Our computational approach enabled to predict novel radioresistance driver gene candidates. Additional preclinical and clinical studies are required to further validate the role of VGF and other candidate genes as potential biomarkers for the prediction of radiotherapy responses and as potential targets for radiosensitization of prostate cancer.

Prostate cancer cell lines represent an important model system to characterize molecular alterations that contribute to radioresistance, but irradiation can cause deletions and amplifications of DNA segments that affect hundreds of genes. This in combination with the small number of cell lines that are usually considered does not allow a straight-forward identification of driver genes by standard statistical methods. Therefore, we developed a network-based approach to analyze gene copy number and expression profiles of such cell lines enabling to identify potential driver genes associated with radioresistance of prostate cancer. We used lasso regression in combination with a significance test for lasso to learn a genome-wide prostate cancer-specific gene regulatory network. We used this network for network flow computations to determine impacts of gene copy number alterations on known radioresistance marker genes. Mapping to prostate cancer samples and additional filtering allowed us to identify 14 driver gene candidates that distinguished irradiated prostate cancer patients into early and late relapse groups. In-depth literature analysis and wet-lab validations suggest that our method can predict novel radioresistance driver genes. Additional preclinical and clinical studies are required to further validate these genes for the prediction of radiotherapy responses and as potential targets to radiosensitize prostate cancer.

Transmembrane (TMEM) protein family members: Poorly characterized even if essential for the metastatic process

The majority of cancer-associated deaths are related to secondary tumor formation. This multistep process involves the migration of cancer cells to anatomically distant organs. Metastasis formation relies on cancer cell dissemination and survival in the circulatory system, as well as adaptation to the new tissue notably through genetic and/or epigenetic alterations. A large number of proteins are clearly identified to play a role in the metastatic process but the structures and modes of action of these proteins are essentially unknown or poorly described. In this review, we detail the involvement of members of the transmembrane (TMEM) protein family in the formation of metastases or in the mechanisms leading to cancer cell dissemination such as migration and extra-cellular matrix remodelling. While the phenotype associated with TMEM over or down-expression is clear, the mechanisms by which these proteins allow cancer cell spreading remain, for most of them, unclear. In parallel, the 3D structures of these proteins are presented. Moreover, we proposed that TMEM proteins could be used as prognostic markers in different types of cancers and could represent potential targets for cancer treatment. A better understanding of this heterogeneous family of poorly characterized proteins thus opens perspectives for better cancer patient care.

PTEN Tumor-Suppressor: The Dam of Stemness in Cancer

PTEN is one of the most frequently inactivated tumor suppressor genes in cancer. Loss or variation in PTEN gene/protein levels is commonly observed in a broad spectrum of human cancers, while germline PTEN mutations cause inherited syndromes that lead to increased risk of tumors. PTEN restrains tumorigenesis through different mechanisms ranging from phosphatase-dependent and independent activities, subcellular localization and protein interaction, modulating a broad array of cellular functions including growth, proliferation, survival, DNA repair, and cell motility. The main target of PTEN phosphatase activity is one of the most significant cell growth and pro-survival signaling pathway in cancer: PI3K/AKT/mTOR. Several shreds of evidence shed light on the critical role of PTEN in normal and cancer stem cells (CSCs) homeostasis, with its loss fostering the CSC compartment in both solid and hematologic malignancies. CSCs are responsible for tumor propagation, metastatic spread, resistance to therapy, and relapse. Thus, understanding how alterations of PTEN levels affect CSC hallmarks could be crucial for the development of successful therapeutic approaches. Here, we discuss the most significant findings on PTEN-mediated control of CSC state. We aim to unravel the role of PTEN in the regulation of key mechanisms specific for CSCs, such as self-renewal, quiescence/cell cycle, Epithelial-to-Mesenchymal-Transition (EMT), with a particular focus on PTEN-based therapy resistance mechanisms and their exploitation for novel therapeutic approaches in cancer treatment.

The Role of the Tumor Microenvironment in Neuropilin 1-Induced Radiation Resistance in Lung Cancer Cells

Background: Neuropilin 1 (NRP1) is a pleiotropic receptor which can interact with multiple ligands and their receptors. It plays an important role in the process of axonal growth, angiogenesis, tumor metastasis and radiation resistance in endothelial cells and some tumor cells. Interaction of stromal and tumor cells plays a dynamic role in initiating and enhancing carcinogenesis, and has received considerable attention in recent years.

Material and Methods: In this study, A549 lung cancer cell lines with different NRP1 expression levels were constructed in vitro, a two-dimensional (2D), three-dimensional (3D) co-culture system and tumor-bearing model was established in SCID mice. Western blot, qRT-PCR, immunofluorescence, cytometric bead array and flow cytometry were used to investigate the effect of the tumor microenvironment in NRP1-induced lung cancer cell radiation resistance.

Results: In 2D or 3D co-culture system, NRP1 could be regulated inflammatory factors such as TNF, IL-6 IL-8 and IL-17 and the related chemokines MCP-1, IP-10 and RANTES in the tumor microenvironment, which in turn induced radiation resistance in lung cancer cells. In addition, different expression levels of NRP1 in 2D, 3D culture systems and tumor-bearing models were able to significantly regulate cell phenotype, proliferative capacity, epithelial-mesenchymal transition (EMT) and the radiation resistance of A549 cells.

Conclusion: Our results verified that NRP1, inflammatory factors, chemokines and related signaling pathways, which affect the transformation of related cell components and thus lung cancer cell immune tolerance and migratory ability, all play an important role in radiation resistance.

Dairy Products: Is There an Impact on Promotion of Prostate Cancer? A Review of the Literature

This review of the literature aims to study potential associations between high consumption of milk and/or dairy products and prostate cancer (PC). Literature is scarce, yet there is a direct relationship between mTORC1 activation and PC; several ingredients in milk/dairy products, when in high concentrations, increase signaling of the mTORC1 pathway. However, there are no studies showing an unequivocal relationship between milk products PC initiation and/or progression. Three different reviews were conducted with articles published in the last 5 years: (M1) PC and intake of dairy products, taking into account the possible mTORC1signaling mechanism; (M2) Intake of milk products and incidence/promotion of PC; (M3) mTORC1 activation signaling pathway, levels of IGF-1 and PC; (M4) mTORC pathway and dairy products. Of the 32 reviews identified, only 21 met the inclusion criteria and were analyzed. There is little scientific evidence that directly link the three factors: incidence/promotion of PC, intake of dairy products and PC, and PC and increased mTORC1 signaling. Persistent hyper-activation of mTORC1 is associated with PC promotion. The activity of exosomal mRNA in cellular communication may lead to different impacts of different types of milk and whether or not mammalian milks will have their own characteristics within each species. Based on this review of the literature, it is possible to establish a relationship between the consumption of milk products and the progression of PC; we also found a possible association with PC initiation, hence it is likely that the intake of dairy products should be reduced or minimized in mens' diet.

Predictors of Overall and Disease-Free Survival in Metastatic Castration-Resistant Prostate Cancer Patients Receiving 225Ac-PSMA-617 Radioligand Therapy

Metastatic prostate carcinoma overexpresses prostate-specific membrane antigen (PSMA), making this antigen a suitable target for radioligand therapy of the disease. Here we report on our experience with a series of 73 castration-resistant prostate carcinoma patients treated with ²²⁵Ac-PSMA-617, identifying variables predictive for overall survival (OS) and progression-free survival (PFS) after ²²⁵Ac-PSMA-617 treatment. Methods: ²²⁵Ac-PSMA-617 was administered to patients who had metastatic castration-resistant prostate carcinoma and who had exhausted available therapy options for their disease. Full blood count, glomerular filtration rate, and liver function test were obtained at baseline and on follow-up for evaluation of toxicity. ⁶⁸Ga-PSMA PET/CT was obtained at baseline, before every treatment cycle, and on follow-up for selection of patients for treatment, to determine the activity of the treatment agent to be administered, and for response assessment. Serial prostate-specific antigen (PSA) was obtained for PSA response assessment. Results: Seventy-three men (mean age, 69 y; range, 45-85 y) with metastatic castration-resistant prostate carcinoma were treated with 210 cycles of ²²⁵Ac-PSMA-617. In 70% of patients, a PSA decline of greater than or equal to 50% was obtained; 82% of patients had any PSA decline. In 29% of patients, all lesions on ⁶⁸Ga-PSMA PET resolved in response to treatment. During follow-up, 23 patients experienced disease progression, whereas 13 patients died from their disease. The estimated median PFS and OS were 15.2 mo (95% CI, 13.1-17.4) and 18 mo (95% CI, 16.2-19.9), respectively. In univariate analyses, factors such as baseline PSA, any PSA decline, PSA decline of greater than or equal to 50%, prior chemotherapy, prior radiation therapy, and baseline hemoglobin level were associated with longer PFS and OS (all Ps < 0.05). In multivariate analyses, there was a negative association between prior ¹⁷⁷Lu-PSMA therapy and PFS, and a positive association between PSA decline of greater or equal to 50% and PFS. Only a PSA decline of greater than or equal to 50% remained significantly associated with OS on multivariate analyses. Xerostomia was seen in 85% of patients but was not severe enough to warrant discontinuing treatment. Anemia was seen in 27 patients; no patients had grade IV bone marrow toxicity. Renal failure of grade III or IV was seen in 5 patients with baseline renal impairment. Conclusion: In this study, a PSA decline of greater than or equal to 50% after treatment with ²²⁵Ac-PSMA-617 was proven by multivariate analyses to be significantly associated with OS and PFS. Furthermore, previous ¹⁷⁷Lu-PSMA treatment was negatively associated with PFS in both univariate and multivariate analyses.

Contribution of Epithelial Plasticity to Therapy Resistance

Therapy resistance is responsible for tumour recurrence and represents one of the major challenges in present oncology. Significant advances have been made in the understanding of the mechanisms underlying resistance to conventional and targeted therapies improving the clinical management of relapsed patients. Unfortunately, in too many cases, resistance reappears leading to a fatal outcome. The recent introduction of immunotherapy regimes has provided an unprecedented success in the treatment of specific cancer types; however, a good percentage of patients do not respond to immune-based treatments or ultimately become resistant. Cellular plasticity, cancer cell stemness and tumour heterogeneity have emerged as important determinants of treatment resistance. Epithelial-to-mesenchymal transition (EMT) is associated with resistance in many different cellular and preclinical models, although little evidence derives directly from clinical samples. The recognition of the presence in tumours of intermediate hybrid epithelial/mesenchymal states as the most likely manifestation of epithelial plasticity and their potential link to stemness and tumour heterogeneity, provide new clues to understanding resistance and could be exploited in the search for anti-resistance strategies. Here, recent evidence linking EMT/epithelial plasticity to resistance against conventional, targeted and immune therapy are summarized. In addition, future perspectives for related clinical approaches are also discussed.

URG11 promotes proliferation and induced apoptosis of LNCaP cells

von Willebrand factor C and EGF domain-containing protein (URG11), a cell growth regulator, is involved in the progression of a variety of types of cancer, including prostate cancer (Pca). However, the functions of the URG11 gene in Pca cells require in-depth investigation. The mRNA and protein levels of URG11 were measured by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. Cell Counting kit-8 (CCK-8), wound-healing and Transwell assays were used to detect cell viability, migration and invasion, respectively. Apoptosis and cell cycle analyses were performed using flow cytometry. The mRNA and protein expression levels of epithelial (E)-cadherin, vimentin, α-smooth muscle actin (α-SMA), cyclin D1 and MYC proto-oncogene protein (c-Myc) were analyzed by RT-qPCR and western blot analysis. In the present study, the mRNA and protein levels of URG11 were markedly upregulated in Pca cell lines compared with those in the normal prostate epithelial cell line. With functional experiments, the cell viability, migration and invasion of Pca cells were markedly promoted by URG11 overexpression. The cell cycle was effectively induced by URG11 and apoptosis was inhibited by the overexpression of URG11. Concomitantly, the epithelial marker E-cadherin was downregulated, and the mesenchymal markers vimentin and α-SMA were upregulated following URG11 overexpression. By contrast, genetic knockout of URG11 elicited the opposite effects. The present study also identified that the downstream effector genes of the Wnt/β-catenin signal pathway, cyclin D1 and c-Myc, were increased following the overexpression of endogenous URG11, which are known to regulate cell proliferation. In addition, the Wnt/β-catenin inhibitor FH535 ameliorated the promotive effects of URG11 on LNCaP cells viability, migration and invasion, and the Wnt/β-catenin agonist LiCl reversed the inhibitory effects of siURG11 in LNCaP cells on cell viability, migration and invasion. The present study demonstrated that URG11 served an oncogenic role in the development of Pca cells and provided evidence that URG11 has potential as a novel therapeutic target in Pca.

Quantitative Single-Cell Analysis of Isolated Cancer Cells with a Microwell Array

The heterogeneous nature of tumor-cell populations suggests that quantitative analysis at the single-cell level may provide better insights into cancer biology. Specifically, detection of multiple biomarkers from a single cell offers important initial information about cellular behavior. However, conventional approaches limit biomarker detection at the single-cell level. Here, we fabricated a polymer microwell array to capture single cells from prostate-cancer cell lines and quantitatively analyzed the expression of three different cancer-related biomarkers, CD44, EpCAM, and PSMA, without a membrane protein-extraction step. The resulting information on cell-surface biomarker distributions was compared with that from other standard analytical techniques. Interestingly, a large variation in CD44-expression levels was observed when the cell-proliferation cycle was modulated. On the other hand, the expression levels of EpCAM in three different cell lines are consistent among the different analytical methods with the exception of the microarray, where it has a different substrate material to adhere to. This observation clearly emphasizes that biomarker choice and environmental control are critical for properly understanding the single-cell state.

miR-205 enhances radiation sensitivity of prostate cancer cells by impairing DNA damage repair through PKCε and ZEB1 inhibition

BACKGROUND

Radiotherapy is one of the main treatment options for non-metastatic prostate cancer (PCa). Although treatment technical optimization has greatly improved local tumor control, a considerable fraction of patients still experience relapse due to the development of resistance. Radioresistance is a complex and still poorly understood phenomenon involving the deregulation of a variety of signaling pathways as a consequence of several genetic and epigenetic abnormalities. In this context, cumulative evidence supports a functional role of microRNAs in affecting radioresistance, suggesting the modulation of their expression as a novel radiosensitizing approach. Here, we investigated for the first time the ability of miR-205 to enhance the radiation response of PCa models.

METHODS

miR-205 reconstitution by a miRNA mimic in PCa cell lines (DU145 and PC-3) was used to elucidate miR-205 biological role. Radiation response in miRNA-reconstituted and control cells was assessed by clonogenic assay, immunofluorescence-based detection of nuclear γ-H2AX foci and comet assay. RNAi was used to silence the miRNA targets PKCε or ZEB1. In addition, target-protection experiments were carried out using a custom oligonucleotide designed to physically disrupt the pairing between the miR-205 and PKCε. For in vivo experiments, xenografts generated in SCID mice by implanting DU145 cells stably expressing miR-205 were exposed to 5-Gy single dose irradiation using an image-guided animal micro-irradiator.

RESULTS

miR-205 reconstitution was able to significantly enhance the radiation response of prostate cancer cell lines and xenografts through the impairment of radiation-induced DNA damage repair, as a consequence of PKCε and ZEB1 inhibition. Indeed, phenocopy experiments based on knock-down of either PKCε or ZEB1 reproduced miR-205 radiosensitizing effect, hence confirming a functional role of both targets in the process. At the molecular level, miR-205-induced suppression of PKCε counteracted radioresistance through the impairment of EGFR nuclear translocation and the consequent DNA-PK activation. Consistently, disruption of miR-205-PKCε 3'UTR pairing almost completely abrogated the radiosensitizing effect.

CONCLUSIONS

Our results uncovered the molecular and cellular mechanisms underlying the radiosensitizing effect of miR-205. These findings support the clinical interest in developing a novel therapeutic approach based on miR-205 reconstitution to increase PCa response to radiotherapy.

Cirsiliol Suppressed Epithelial to Mesenchymal Transition in B16F10 Malignant Melanoma Cells through Alteration of the PI3K/Akt/NF-κB Signaling Pathway

Malignant melanoma is a highly aggressive form of skin cancer which has a propensity for metastasis. Epithelial mesenchymal transition (EMT) plays a primordial role in the progression of metastatic disease. Metastatic melanoma is resistant to conventional therapies. Hence, researchers have been exploring alternative approaches, including the utility of bioactive phytochemicals to manage metastatic disease. In the present study, we investigated the potential of cirsiliol, a flavonoid isolated from Centaurea jacea L., in modulating the aggressive behavior of B16F10 metastatic melanoma cells, including EMT, and associated molecular mechanisms of action. Cirsiliol was found to be effective in restraining the colony formation and migration of fibronectin-induced B16F10 metastatic melanoma cells. Cirsiliol inhibited the activity and expression of matrix metalloproteinase-9 (MMP-9). Cirsiliol also suppressed the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (also known as Akt)/nuclear factor-κB (NF-κB) signaling pathway which, in turn, caused upregulation of E-cadherin and downregulation of N-cadherin, Snail and Twist. Based on these results, cirsiliol may be considered a promising compound against EMT in the therapeutic management of malignant melanoma.

Radiosensitivity nomogram based on circulating neutrophils in thoracic cancer

AIM

To evaluate the prediction ability of neutrophils and develop a nomogram on radiosensitivity in thoracic cancer patients.

METHODS

We retrospectively reviewed 398 lung and esophageal cancers patients who received external-beam radiotherapy or concurrent chemoradiotherapy as first-line therapy.

RESULTS

Logistic regression model showed that patients with low levels of neutrophil counts and/or TGF-β1 exhibited better radiation sensitivity. Furthermore, a nomogram was created to predict radiotherapy sensitivity. The combination of neutrophil count and TGF-β1 level was an independent prognostic factor for lung and esophageal cancers patients.

CONCLUSION

The study developed a nomogram based on the levels of circulating neutrophils and TGF-β1. The prediction value in radiosensitivity and protumorigenic effect of neutrophils might owe to N2 tumor-associated neutrophils.

miR-17-3p Downregulates Mitochondrial Antioxidant Enzymes and Enhances the Radiosensitivity of Prostate Cancer Cells

Radioresistance remains to be a major obstacle in the management of patients with advanced prostate cancer (PCa). We have identified a mature miR-17-3p processed from the 3' arm of precursor miR-17, which appeared to be able to inhibit three major antioxidant enzymes located in mitochondria, i.e., manganese superoxide dismutase (MnSOD), glutathione peroxidase 2 (Gpx2), and thioredoxin reductase 2 (TrxR2). Here we show that upregulation of miR-17-3p remarkably sensitized PCa cells to ionizing radiation (IR). Reductions of the three antioxidants led to increasing cellular reactive oxygen species (ROS) accumulation as well as declining mitochondrial respiration. The miR-17-3p-mediated dysfunction of mitochondrial antioxidants apparently sensitizing IR therapy was manifested in vitro and in vivo. Substantially, the miR-17-3p effect on suppression of the antioxidants can be efficiently eliminated or attenuated by transfecting with either an miR-17-3p inhibitor or each of the related antioxidant cDNA expression constructs. Overall, in addition to the insights into the functional assessments for the duplex of miR-17-5p and miR-17-3p, the present study highlights the rigorous evidence that demonstrated suppression of multiple mitochondrial antioxidants by a single microRNA (miRNA), thereby providing a promising approach to improve radiotherapy for advanced PCa by targeting mitochondrial function.

IMPDH2 promotes colorectal cancer progression through activation of the PI3K/AKT/mTOR and PI3K/AKT/FOXO1 signaling pathways

Background

Inosine 5′-monophosphate dehydrogenase type II (IMPDH2) was originally identified as an oncogene in several human cancers. However, the clinical significance and biological role of IMPDH2 remain poorly understood in colorectal cancer (CRC).

Methods

Quantitative real-time polymerase chain reaction (qPCR), western blotting analysis, the Cancer Genome Atlas (TCGA) data mining and immunohistochemistry were employed to examine IMPDH2 expression in CRC cell lines and tissues. A series of in-vivo and in-vitro assays were performed to demonstrate the function of IMPDH2 and its possible mechanisms in CRC.

Results

IMPDH2 was upregulated in CRC cells and tissues at both mRNA and protein level. High IMPDH2 expression was closely associated with T stage, lymph node state, distant metastasis, lymphovascular invasion and clinical stage, and significantly correlated with poor survival of CRC patients. Further study revealed that overexpression of IMPDH2 significantly promoted the proliferation, invasion, migration and epithelial-mesenchymal transition (EMT) of CRC cells in vitro and accelerated xenograft tumour growth in nude mice. On the contrary, knockdown of IMPDH2 achieved the opposite effect. Gene set enrichment analysis (GSEA) showed that the gene set related to cell cycle was linked to upregulation of IMPDH2 expression. Our study verified that overexpressing IMPDH2 could promote G1/S phase cell cycle transition through activation of PI3K/AKT/mTOR and PI3K/AKT/FOXO1 pathways and facilitate cell invasion, migration and EMT by regulating PI3K/AKT/mTOR pathway.

Conclusions

These results suggest that IMPDH2 plays an important role in the development and progression of human CRC and may serve as a novel prognostic biomarker and therapeutic target for CRC.

Activation of tumor cell integrin αvβ3 by radiation and reversal of activation by chemically modified tetraiodothyroacetic acid (tetrac)

PURPOSE

Integrin αvβ3 is an important structural and signaling protein of the plasma membrane of cancer cells and dividing blood vessel cells. The plastic extracellular domain of the protein binds to extracellular matrix proteins and plasma membrane proteins, changing cell-cell interactions and generating intracellular signals that influence cell behavior. αvβ3 also contains a receptor for thyroid hormone and derivatives, including tetraiodothyroacetic acid (tetrac).

MATERIALS AND METHODS

Human prostate cancer (PC3) cells were engrafted in the chicken chorioallantoic membrane model. The well-vascularized spheroidal xenografts were exposed to X-radiation in varying dosages (1-10 Gy) and in the presence and absence of an antibody that recognizes unliganded human β3 integrin monomer in the extended or open (activated) configuration.

RESULTS

Radiation significantly increased activated β3 within 1 h (P < .001), a radiation response not previously reported. Incubation of cells with unmodified tetrac or tetrac covalently linked to a nanoparticle (Nanotetrac, NDAT) did not change basal activation state of the integrin monomer, but prevented radiation-induced activation of β3.

CONCLUSIONS

Activation of the integrin in response to radiation is interpreted as a defensive response, perhaps leading to increased intercellular affinity and inhibition of cell division, a radioresistant state. Action of NDAT indicates that pharmacologic interventions in the radiation response of integrin β3 monomer and therefore of αvβ3 are feasible.