Vitamin D-induced vitamin D receptor expression induces tamoxifen sensitivity in MCF-7 stem cells via suppression of Wnt/β-catenin signaling

Vitamin D receptor is associated with prognostic characteristics of breast cancer after neoadjuvant chemotherapy-an observational study

Background

Breast cancer (BC) is the most commonly diagnosed malignant tumor in women. The disease and its subsequent treatment pose a serious burden on the quality of life of patients. Neoadjuvant chemotherapy (NAC) has become one of the crucial strategies for the management of BC. Since the identification of the vitamin D receptor (VDR) in mammary tissues, extensive mechanistic research has been conducted on its function. The expression of VDR in BC cells and the tumor microenvironment could be a new prognostic factor for BC after NAC.

Patients and Methods

This observational, single-center study compared data from clinical and histopathological records of 111 female subjects with the expression of VDR in different cellular and tissue components of breast specimens obtained from surgery after NAC. VDR expression was evaluated using an immunoreactive score assigned after immunohistochemistry. Intergroup comparisons and logistic regression were used to identify associations between VDR expression and clinicopathological features of BC.

Results

We found that the expression of VDR is associated with various clinical features (i.e., age, menopausal status, and NAC cycle number) and characteristics of prognostic significance, such as residual cancer burden class. Logistic regression analysis revealed that the expression of VDR in the nuclei and cytoplasm of surrounding normal mammary cells predicted vascular invasion and lymph node involvement.

Conclusions

The expression of VDR in tumor cells and their microenvironment is related to the clinicopathological characteristics of BC after NAC.

Vitamin D suppresses CD133+/CD44 + cancer stem cell stemness by inhibiting NF-κB signaling and reducing NLRP3 expression in triple-negative breast cancer

BACKGROUND AND OBJECTIVE

This study aims to investigate the role of Vitamin D (VD) in regulating the stemness and survival of CD133+/CD44 + breast cancer stem cells, and to explore the role of NLRP3 in this process.

METHODS

Breast cancer tissues were collected for RXRα and VDR expression analysis. A triple-negative breast cancer cell line was cultured and stem-like cells (CD133 + CD44+) isolated using flow cytometry. These cells were treated with VD, analyzing their stem-like properties, apoptosis and proliferation, as well as P65 nuclear expression and NLRP3 expression. After NLRP3 inflammasome activator treatment, the parameters were reassessed. RXRα and VDR interaction was confirmed using co-immunoprecipitation (CoIP). Finally, a subcutaneous xenograft model of triple-negative breast cancer was treated with VD and subsequently analyzed for stem-like properties, proliferation, apoptosis, and NLRP3 expression levels.

RESULTS

CD133+/CD44 + stem cells expressed high levels of SOX2 and OCT4. VD treatment resulted in a significant decrease in SOX2 and OCT4 expression, fewer sphere-forming colonies, lower proliferation ability, and more apoptosis. Additionally, VD treatment inhibited NF-κB signaling and reduced NLRP3 expression. The NLRP3 activator BMS-986,299 counteracted the effects of VD in vitro. In vivo, VD inhibited the growth of breast cancer stem cells, reducing both tumor volume and weight, and decreased NLRP3, SOX2, and OCT4 expression within tumor tissues.

CONCLUSION

Findings elucidate that VD mediates the modulation of stemness in CD133+/CD44 + breast cancer stem cells through the regulation of NLRP3 expression. The research represents novel insights on the implications for the application of VD in cancer therapies.

A 3'-pre-tRNA-derived small RNA tRF-1-Ser regulated by 25(OH)D promotes proliferation and stemness by inhibiting the function of MBNL1 in breast cancer

BACKGROUND

We explored the potential novel anticancer mechanisms of 25-hydroxyvitamin D (25(OH)D), a vitamin D metabolite with antitumour effects in breast cancer. It is stable in serum and is used to assess vitamin D levels in clinical practice. Transfer RNA-derived small RNAs are small noncoding RNAs that generate various distinct biological functions, but more research is needed on their role in breast cancer.

METHODS

Small RNA microarrays were used to explore the novel regulatory mechanism of 25(OH)D. High-throughput RNA-sequencing technology was used to detect transcriptome changes after 25(OH)D treatment and tRF-1-Ser knockdown. RNA pull-down and high-performance liquid chromatography-mass spectrometry/mass spectrometry were used to explore the proteins bound to tRF-1-Ser. In vitro and in vivo functional experiments were conducted to assess the influence of 25(OH)D and tRF-1-Ser on breast cancer. Semi-quantitative PCR was performed to detect alternative splicing events. Western blot assay and qPCR were used to assess protein and mRNA expression.

RESULTS

The expression of tRF-1-Ser is negatively regulated by 25(OH)D. In our breast cancer (BRCA) clinical samples, we found that the expression of tRF-1-Ser was higher in cancer tissues than in paired normal tissues, and was significantly associated with tumour invasion. Moreover, tRF-1-Ser inhibits the function of MBNL1 by hindering its nuclear translocation. Functional experiments and transcriptome data revealed that the downregulation of tRF-1-Ser plays a vital role in the anticancer effect of 25(OH)D.

CONCLUSIONS

In brief, our research revealed a novel anticancer mechanism of 25(OH)D, unveiled the vital function of tRF-1-Ser in BRCA progression, and suggested that tRF-1-Ser could emerge as a new therapeutic target for BRCA.

Dynamic interplay of nuclear receptors in tumor cell plasticity and drug resistance: Shifting gears in malignant transformations and applications in cancer therapeutics

Recent advances have brought forth the complex interplay between tumor cell plasticity and its consequential impact on drug resistance and tumor recurrence, both of which are critical determinants of neoplastic progression and therapeutic efficacy. Various forms of tumor cell plasticity, instrumental in facilitating neoplastic cells to develop drug resistance, include epithelial-mesenchymal transition (EMT) alternatively termed epithelial-mesenchymal plasticity, the acquisition of cancer stem cell (CSC) attributes, and transdifferentiation into diverse cell lineages. Nuclear receptors (NRs) are a superfamily of transcription factors (TFs) that play an essential role in regulating a multitude of cellular processes, including cell proliferation, differentiation, and apoptosis. NRs have been implicated to play a critical role in modulating gene expression associated with tumor cell plasticity and drug resistance. This review aims to provide a comprehensive overview of the current understanding of how NRs regulate these key aspects of cancer biology. We discuss the diverse mechanisms through which NRs influence tumor cell plasticity, including EMT, stemness, and metastasis. Further, we explore the intricate relationship between NRs and drug resistance, highlighting the impact of NR signaling on chemotherapy, radiotherapy and targeted therapies. We also discuss the emerging therapeutic strategies targeting NRs to overcome tumor cell plasticity and drug resistance. This review also provides valuable insights into the current clinical trials that involve agonists or antagonists of NRs modulating various aspects of tumor cell plasticity, thereby delineating the potential of NRs as therapeutic targets for improved cancer treatment outcomes.

MicroRNAs in Anticancer Drugs Hepatotoxicity: From Pathogenic Mechanism and Early Diagnosis to Therapeutic Targeting by Natural Products

Patients receiving cancer therapies experience severe adverse effects, including hepatotoxicity, even at therapeutic doses. Consequently, monitoring patients on cancer therapy for hepatic functioning is necessary to avoid permanent liver damage. Several pathways of anticancer drug-induced hepatotoxicity involve microRNAs (miRNAs) via targeting mRNAs. These short and non-coding RNAs undergo rapid modulation in non-targeted organs due to cancer therapy insults. Recently, there has been an interest for miRNAs as useful and promising biomarkers for monitoring toxicity since they have conserved sequences across species and are cellular-specific, stable, released during injury, and simple to analyze. Herein, we tried to review the literature handling miRNAs as mediators and biomarkers of anticancer drug-induced hepatotoxicity. Natural products and phytochemicals are suggested as safe and effective candidates in treating cancer. There is also an attempt to combine anticancer drugs with natural compounds to enhance their efficiencies and reduce systemic toxicities. We also discussed natural products protecting against chemotherapy hepatotoxicity via modulating miRNAs, given that miRNAs have pathogenic and diagnostic roles in chemotherapy-induced hepatotoxicity and that many natural products can potentially regulate their expression. Future studies should integrate these findings into clinical trials by formulating suitable therapeutic dosages of natural products to target miRNAs involved in anticancer drug hepatotoxicity.

Vitamin D3 Inhibits the Viability of Breast Cancer Cells In Vitro and Ehrlich Ascites Carcinomas in Mice by Promoting Apoptosis and Cell Cycle Arrest and by Impeding Tumor Angiogenesis

The incidence of aggressive and resistant breast cancers is growing at alarming rates, indicating a necessity to develop better treatment strategies. Recent epidemiological and preclinical studies detected low serum levels of vitamin D in cancer patients, suggesting that vitamin D may be effective in mitigating the cancer burden. However, the molecular mechanisms of vitamin D3 (cholecalciferol, vit-D3)-induced cancer cell death are not fully elucidated. The vit-D3 efficacy of cell death activation was assessed using breast carcinoma cell lines in vitro and a widely used Ehrlich ascites carcinoma (EAC) breast cancer model in vivo in Swiss albino mice. Both estrogen receptor-positive (ER+, MCF-7) and -negative (ER-, MDA-MB-231, and MDA-MB-468) cell lines absorbed about 50% of vit-D3 in vitro over 48 h of incubation. The absorbed vit-D3 retarded the breast cancer cell proliferation in a dose-dependent manner with IC50 values ranging from 0.10 to 0.35 mM. Prolonged treatment (up to 72 h) did not enhance vit-D3 anti-proliferative efficacy. Vit-D3-induced cell growth arrest was mediated by the upregulation of p53 and the downregulation of cyclin-D1 and Bcl2 expression levels. Vit-D3 retarded cell migration and inhibited blood vessel growth in vitro as well as in a chorioallantoic membrane (CAM) assay. The intraperitoneal administration of vit-D3 inhibited solid tumor growth and reduced body weight gain, as assessed in mice using a liquid tumor model. In summary, vit-D3 cytotoxic effects in breast cancer cell lines in vitro and an EAC model in vivo were associated with growth inhibition, the induction of apoptosis, cell cycle arrest, and the impediment of angiogenic processes. The generated data warrant further studies on vit-D3 anti-cancer therapeutic applications.

Discovery of small molecule β-catenin suppressors that enhance immunotherapy

Small molecules directly downregulating β-catenin could potentially offer a more effective therapeutic approach for combating against cancer stem cells, as compared to targeting the downstream components of the Wnt/β-catenin pathway. The challenge, however, lies in the fact that very few β-catenin suppressors have proven clinically effective, leaving a significant gap in medical solutions. Given that E-cadherin has a natural affinity for β-catenin, it stands to reason that agents designed to increase E-cadherin expression might provide an alternative method of regulating β-catenin levels. In this study, we report our discovery of DSS-C12 and DSS-B8, specific ester-based drugs derived from Dan-Shen-Su (DSS) extracted from the herb Salvia miltiorrhiza. Remarkably, these compounds display a potent ability to downregulate β-catenin, while also improving overall survival in post-surgery mice. Additionally, when these drugs are used in combination with PD-L1 checkpoint blockade, they stimulate enhanced systemic immune responses leading to significant suppression of primary tumor growth. In-depth mechanistic studies revealed that DSS-B8 functions as a vitamin D receptor agonist without inducing hypercalcemic effects. Collectively, our findings indicate that DSS-derived small molecules have considerable potential as clinically viable therapeutic strategies for β-catenin deactivation.

Association of CYP24A1 with survival and drug resistance in clinical cancer patients: a meta-analysis

BACKGROUND

Acquired chemo-drug resistance constantly led to the failure of chemotherapy for malignant cancers, consequently causing cancer relapse. Hence, identifying the biomarker of drug resistance is vital to improve the treatment efficacy in cancer. The clinical prognostic value of CYP24A1 remains inconclusive, hence we aim to evaluate the association between CYP24A1 and the drug resistance in cancer patients through a meta-analysis approach.

METHOD

Relevant studies detecting the expression or SNP of CYP24A1 in cancer patients up till May 2022 were systematically searched in four common scientific databases including PubMed, EMBASE, Cochrane library and ISI Web of Science. The pooled hazard ratios (HRs) indicating the ratio of hazard rate of survival time between CYP24A1^high population vs CYP24A1^low population were calculated. The pooled HRs and odds ratios (ORs) with 95% confidence intervals (CIs) were used to explore the association between CYP24A1's expression or SNP with survival, metastasis, recurrence, and drug resistance in cancer patients.

RESULT

Fifteen studies were included in the meta-analysis after an initial screening according to the inclusion and exclusion criteria. There was a total of 3784 patients pooled from all the included studies. Results indicated that higher expression or SNP of CYP24A1 was significantly correlated with shorter survival time with pooled HRs (95% CI) of 1.21 (1.12, 1.31), metastasis with pooled ORs (95% CI) of 1.81 (1.11, 2.96), recurrence with pooled ORs (95% CI) of 2.14 (1.45, 3.18) and drug resistance with pooled HRs (95% CI) of 1.42 (1.17, 1.68). In the subgroup analysis, cancer type, treatment, ethnicity, and detection approach for CYP24A1 did not affect the significance of the association between CYP24A1 expression and poor prognosis.

CONCLUSION

Findings from our meta-analysis demonstrated that CYP24A1's expression or SNP was correlated with cancer progression and drug resistance. Therefore, CYP24A1 could be a potential molecular marker for cancer resistance.

Vitamin D Reverts the Exosome-Mediated Transfer of Cancer Resistance to the mTOR Inhibitor Everolimus in Hepatocellular Carcinoma

Several multi-kinase inhibitors were widely tested as potential first-line or second-line therapy in patients with advanced hepatocellular carcinoma (HCC). However, acquired drug resistance limits their clinical efficacy. Exosomes are microvesicles secreted by tumor and stromal cells that participate in many biological processes, including drug resistance. The current study evaluated the capability of exosomes derived from everolimus (EVE)-resistant HCC cells in inducing drug resistance in parental human HCC cells and the effect of 1,25(OH)₂Vitamin D (VitD) treatment in restoring EVE sensitivity. The internalization of exosomes from EVE-resistant (EveR) cells into parental cells conferred the transmission of aggressive phenotype by promoting the transition of epithelial-to-mesenchymal phenotype, as demonstrated by immunofluorescence, and the acquisition of EVE resistance, as demonstrated by cell proliferation and colony formation assays. Moreover, the internalization of exosomes from EveR into parental cells induced deregulation of the mTOR pathway mainly by triggering the activation of the serine/threonine protein kinase Akt, involved in the cellular survival pathway, as demonstrated by Western blot analysis. Interestingly, the treatment with VitD prevented exosome-induced EVE resistance in HCC cells, significantly inhibiting cell proliferation but also partially reducing colony and size number when combined with EVE compared with control. In conclusion, the results of the current study demonstrated that exosomes derived from EveR cells could induce EVE resistance in EVE-sensitive HCC cells and that VitD can revert the exosome-induced EVE resistance by resensitizing to EVE treatment.

Brominated flame retardants effect in MCF-7 cells: Impact on vitamin D pathway

Brominated flame retardants (BFRs) are persistent environmental pollutants, allowing a constant human exposure which carries several health risks, including the occurrence of breast cancer and vitamin D deficiency. Vitamin D inhibits cell growth and is negatively associated with breast cancer risk. The effect of BFRs in breast cancer and vitamin D pathway is still poorly understood. MCF-7 cells were treated with hexabromocyclododecane (HBCD), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), hexabromobenzene (HBB) and pentabromotoluene (PBT) using short and long-term exposure protocols. Viability, proliferation, migration, cell cycle and gene expression were assessed. Gene expression of hVDBP and hCYP2R1 was also evaluated in hepatocytes. Long-term exposure of MCF-7 cells to HBB increased cell proliferation and migration, consequently increasing MMP-9 expression. The vitamin D pathway was also altered by BFRs: cells appeared less prepared to activate and transport vitamin D and the signaling, action and inactivation mechanisms were diminished in the presence of BFRs. Untreated MCF-7 cells showed cell cycle arrest in phase G0/G1 in the presence of activated vitamin D. However, when MCF-7 cells were exposed to BFRs, cell cycle was arrested in phase G2/M, possibly due to DNA damage. Nonetheless, calcitriol seems to be able to mitigate the effect of some BFRs exposure, e.g. PBT.

Claudin1 decrease induced by 1,25-dihydroxy-vitamin D3 potentiates gefitinib resistance therapy through inhibiting AKT activation-mediated cancer stem-like properties in NSCLC cells

Claudins, the integral tight junction proteins that regulate paracellular permeability and cell polarity, are frequently dysregulated in cancer; however, their roles in regulating EGFR tyrosine kinase inhibitors (EGFR-TKIs) resistance in non-small cell lung cancer (NSCLC) are unknown. To this end, we performed GEO dataset analysis and identified that claudin1 was a critical regulator of EGFR-TKI resistance in NSCLC cells. We also found that claudin1, which was highly induced by continuous gefitinib treatment, was significantly upregulated in EGFR-TKI-resistant NSCLC cells. By knocking down claudin1 in cell lines and xenograft models, we established that gefitinib resistance was decreased. Moreover, claudin1 knockdown suppressed the expression levels of pluripotency markers (Oct4, Nanog, Sox2, CD133, and ALDH1A1). Claudin1 loss inhibited phosphorylated AKT (p-AKT) expression and reduced cancer cell stemness by suppressing AKT activation. Furthermore, SKL2001, a β-catenin agonist, upregulated the expression levels of claudin1, p-AKT, and pluripotency markers, and 1,25-dihydroxy-vitamin D3 (1,25(OH)₂D₃) reduced claudin1 expression, AKT activation, and cancer cell stemness by inhibiting β-catenin, and suppressed claudin1/AKT pathway mediated cancer stem-like properties and gefitinib resistance. Collectively, inhibition of claudin1-mediated cancer stem-like properties by 1,25(OH)₂D₃ may decrease gefitinib resistance through the AKT pathway, which may be a promising therapeutic strategy for inhibiting gefitinib resistance in EGFR-mutant lung adenocarcinoma.

Vitamin D May Protect against Breast Cancer through the Regulation of Long Noncoding RNAs by VDR Signaling

Dietary vitamin D3 has attracted wide interest as a natural compound for breast cancer prevention and therapy, supported by in vitro and animal studies. The exact mechanism of such action of vitamin D3 is unknown and may include several independent or partly dependent pathways. The active metabolite of vitamin D3, 1α,25-dihydroxyvitamin D3 (1,25(OH)2D, calcitriol), binds to the vitamin D receptor (VDR) and induces its translocation to the nucleus, where it transactivates a myriad of genes. Vitamin D3 is involved in the maintenance of a normal epigenetic profile whose disturbance may contribute to breast cancer. In general, the protective effect of vitamin D3 against breast cancer is underlined by inhibition of proliferation and migration, stimulation of differentiation and apoptosis, and inhibition of epithelial/mesenchymal transition in breast cells. Vitamin D3 may also inhibit the transformation of normal mammary progenitors into breast cancer stem cells that initiate and sustain the growth of breast tumors. As long noncoding RNAs (lncRNAs) play an important role in breast cancer pathogenesis, and the specific mechanisms underlying this role are poorly understood, we provided several arguments that vitamin D3/VDR may induce protective effects in breast cancer through modulation of lncRNAs that are important for breast cancer pathogenesis. The main lncRNAs candidates to mediate the protective effect of vitamin D3 in breast cancer are lncBCAS1-4_1, AFAP1 antisense RNA 1 (AFAP1-AS1), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), long intergenic non-protein-coding RNA 511 (LINC00511), LINC00346, small nucleolar RNA host gene 6 (SNHG6), and SNHG16, but there is a rationale to explore several other lncRNAs.

Comparative pharmacokinetic study of bicalutamide administration alone and in combination with vitamin D in rats

Bicalutamide (BCL) has been approved for treatment of advanced prostate cancer (Pca), and vitamin D is inevitably used in combination with BCL in Pca patients for skeletal or anti-tumor strategies. Therefore, it is necessary to study the effect of vitamin D application on the pharmacokinetics of BCL.

We developed and validated a specific, sensitive and rapid UHPLC–MS/MS method to investigate the pharmacokinetic behaviours of BCL in rat plasma with and without the combined use of vitamin D. Plasma samples were extracted by protein precipitation with ether/dichloromethane (2:1 v/v), and the analytes were separated by a Kinetex Biphenyl 100A column (2.1 × 100 mm, 2.6 μm) with a mobile phase composed of 0.5 mM ammonium acetate (PH 6.5) in water (A) and acetonitrile (B) in a ratio of A:B = 35:65 (v/v). Analysis of the ions was run in the multiple reactions monitoring (MRM) mode. The linear range of BCL was 5–2000 ng mL−1. The intra- and inter-day precision were less than 14%, and the accuracy was in the range of 94.4–107.1%. The mean extraction recoveries, matrix effects and stabilities were acceptable for this method. The validated method was successfully applied to evaluate the pharmacokinetic behaviours of BCL in rat plasma. The results demonstrated that the pharmacokinetic property of BCL is significantly affected by combined use of vitamin D, which might help provide useful evidence for the clinical therapy and further pharmacokinetic study.

MACC1 regulates the AKT/STAT3 signaling pathway to induce migration, invasion, cancer stemness, and suppress apoptosis in cervical cancer cells

Cervical cancer (CC) ranks as the second most frequent tumor in women, and CC stem cells have been vital in the tumorigenesis of CC. Recently, the metastasis- associated in colon cancer 1 (MACC1) gene was proven to be a promising biomarker of CC. However, the role and mechanism of MACC1 in CC remain undetermined. Expressions of MACC1 were estimated by qRT-PCR, immunohistochemistry, and Western blot assays in cervical cancer tissues and cells. Three siRNAs were generated to knockdown expressions of MACC1 in CC cells. After knockdown of MACC1 or/and Colivelin treatment, cell migration, invasion, apoptosis, and stemness were evaluated through a series of functional experiments including Transwell, flow cytometry, Hoechst staining, and sphere-formation assays. MACC1 was found to express more highly in CC tissues in comparison with corresponding non-tumor tissues at both mRNA and protein levels. Functionally, the knocking- down of MACC1 significantly repressed migration and invasion, and induced apoptosis of CC cells. Also, knockdown of MACC1 was discovered to suppress sphere-formation of CC cells and downregulate OCT4 and Nanog. It was proved that knockdown of MACC1 had a significant blocking effect on the AKT/STAT3 pathway. In addition, we verified that treatment with the STAT3 activator (Colivelin) had significant reversal effects on the malignant behaviors of CC cells and CC stemness. Our study concluded that MACC1 might be a novel regulator of CC by regulating the AKT/STAT3 pathway to change the migration, invasion, apoptosis, and cancer stemness of CC cells.

Calcitriol induces estrogen receptor α expression through direct transcriptional regulation and epigenetic modifications in estrogen receptor-negative breast cancer cells

Patients with estrogen receptor (ER) α-negative breast tumors have a poor prognosis and are not suitable for hormone therapy. Previously, we demonstrated that calcitriol, the active metabolite of vitamin D, induces ERα expression and re-establishes the response to antiestrogens in ER-negative breast cancer cells. However, the mechanisms involved in this process have not been elucidated. Therefore, the present study was undertaken to investigate the mechanisms implicated in the calcitriol-induced ERα expression in ER-negative breast cancer cells. Using EMSA and ChIP assays, we found that the calcitriol/vitamin D receptor (VDR)/retinoic X receptor (RXR) complex binds to putative vitamin D response elements (VDREs) in the ERα gene promoter region. In addition, we established by a fluorometric assay that calcitriol decreased DNA-methyltransferase and histone deacetylase activities. Flow cytometry and qPCR analyses showed that co-treatment of calcitriol with inhibitors of the histone deacetylase and DNA methyltransferase, and genistein significantly increased ERα expression, compared to that observed with the compounds alone. In conclusion, the calcitriol-dependent ERα induction in ER-negative breast cancer cells results from binding of the VDR-RXR complex to VDREs in the ERα gene promoter region, including the downregulation of enzymes with chromatin-remodeling activities. These results may bring forth novel mechanistic knowledge into the actions of calcitriol in ERα-negative breast cancer.

The role of AKR1 family in tamoxifen resistant invasive lobular breast cancer based on data mining

Background

Tamoxifen (TAM) resistance to invasive lobular cell carcinoma is a challenge for breast cancer treatment. This study explored the role of Aldo-keto reductase family 1 (AKR1) family in tamoxifen-resistant aggressive lobular breast cancer based on data mining.

Methods

TAM-resistant invasive lobular breast cancer gene chip was downloaded from the Gene Expression Omnibus (GEO) database (accession-numbered as GSE96670). The online analytical tool GEO2R was used to screen for differentially expressed genes in TAM-resistant invasive lobular breast cancer cells and TAM-sensitive counterparts. A protein-protein interaction (PPI) networks were constructed using the STRING online platform and the Cytoscape software. GeneMANIA and GSCALite online tools were used to reveal the potential role of these hub genes in breast cancer progression and TAM resistance development. And the used the GSE67916 microarray data set to verify the differentially expression of these hub genes in breast cancer. The protein expression levels of AKR1C1, AKR1C2 and AKR1C3 in TAM-sensitive and resistant breast cancer cells were compared. The TAM sensitivity of breast cancer cells with or without AKR1C1, AKR1C2 or AKR1C3 gene manipulation was evaluated by cell viability assay.

Results

A total of 184 differentially expressed genes were screened. Compared with TAM sensitive breast cancer cells, 162 were up-regulated and 22 were down-regulated. The study identified several hub genes in the PPI network that may be involved in the development of TAM resistance of breast cancer, including signal transducer and activator of transcription 1 (STAT1), estrogen receptor alpha (ESR1), fibronectin1 (FN1), cytochrome P4501B1 (CYP1B1), AKR1C1, AKR1C2, AKR1C3 and uridine diphosphate glucuronosyltransferase (UGT) 1A family genes (UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A7, UGT1A8, UGT1A9, UGT1A10). Compared with TAM-sensitive counterparts, the expression levels of AKR1C1, AKR1C2, and AKR1C3 were up-regulated in TAM-resistant breast cancer cells.

Conclusions

Overexpression of each of these three genes significantly increased the resistance of breast cancer cells to TAM treatment, while their knockdown showed opposite effects, indicating that they are potential therapeutic target for the treatment of TAM-resistant breast cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-09040-8.

Vitamin D modulates hepatic microRNAs and mitigates tamoxifen-induced steatohepatitis in female rats

Tamoxifen (TAM) is a life-saving and cost-effective drug widely used in the prevention and treatment of breast cancer. However, the adverse effects of tamoxifen can lead to non-adherence and poor patient outcomes. Therefore, exploring novel strategies to improve TAM safety profile is crucial. Given the key role that vitamin D (VD) plays in modulating lipid metabolism and inflammation, in addition to its benefits in reducing risk and progression of breast cancer, we evaluated the protective potential of VD against TAM-induced hepatotoxicity focusing on lipid metabolism and microRNAs (miRNAs) regulation. Female rats were pretreated with VD as cholecalciferol (500 IU/kg/day, po) for 4 weeks before receiving TAM (40 mg/kg/day, po) concurrently with VD during the fifth and sixth weeks. Liver histology, lipid profile and expression of genes, proteins, and miRNAs involved in lipid metabolism and inflammation were examined. TAM-induced steatohepatitis was evidenced by elevated liver triglycerides and cholesterol contents, increased serum miRNA-122 level, and ALT activity, in parallel with accumulation of lipid droplets, focal necrosis, and inflammatory cells infiltration in hepatocytes. Prophylactic use of VD mitigated TAM-induced steatohepatitis by modulating key transcription factors in the liver: PPAR-α, Srebf1, and NF-κB and their downstream genes/proteins Fas, CPT-1A, and TNF-α resulting in reduced hepatic lipids and suppressed pro-inflammatory signaling. Notably, VD pretreatment mitigated TAM-induced alterations in the expression of serum miRNA-122, hepatic miRNA-21, and miRNA-33. The combination therapy of VD and TAM has complementary benefits in terms of safety and not only efficacy and should be further investigated clinically.

Utilizing the Hippo pathway as a therapeutic target for combating endocrine-resistant breast cancer

Drug resistance is always a great obstacle in any endocrine therapy of breast cancer. Although the combination of endocrine therapy and targeted therapy has been shown to significantly improve prognosis, refractory endocrine resistance is still common. Dysregulation of the Hippo pathway is often related to the occurrence and the development of many tumors. Targeted therapies of this pathway have played important roles in the study of triple negative breast cancer (TNBC). Targeting the Hippo pathway in combination with chemotherapy or other targeted therapies has been shown to significantly improve specific antitumor effects and reduce cancer antidrug resistance. Further exploration has shown that the Hippo pathway is closely related to endocrine resistance, and it plays a "co-correlation point" role in numerous pathways involving endocrine resistance, including related pathways in breast cancer stem cells (BCSCs). Agents and miRNAs targeting the components of the Hippo pathway are expected to significantly enhance the sensitivity of breast cancer cells to endocrine therapy. This review initially explains the possible mechanism of the Hippo pathway in combating endocrine resistance, and it concludes by recommending endocrine therapy in combination with therapies targeting the Hippo pathway in the study of endocrine-resistant breast cancers.

Newly-identified Pathways Relating Vitamin D to Carcinogenesis: A Review

BACKGROUND

The epidemiological relationship between vitamin D levels and cancer has been thoroughly investigated. Published data from large studies appear to corroborate a significant relationship between higher serum vitamin D concentrations and improved survival. Mechanistic reviews on commonly-studied cancers - including breast cancer, colon cancer and melanoma - focus predominantly on data from older studies. In outlining avenues for future research, we believe there is utility in summarizing novel findings introduced to the literature.

MATERIALS AND METHODS

In this narrative review, we used MEDLINE, PUBMED and Cochrane databases to identify mechanistic studies published from January 1, 2015 onwards exploring this topic.

RESULTS

Twenty-five mechanistic studies were included in this review. It was found that vitamin D plays a critical role in both direct (i.e. tumor gene expression, proliferation, invasiveness, sensitivity to chemotherapy etc.) and indirect (i.e. effects on the tumor microenvironment and immunomodulation) tumor suppression mechanisms.

CONCLUSION

These newly-identified pathways warrant further research, with the hopes that we may understand how and when vitamin D supplementation can be integrated into precision medicine therapeutics for cancers of the breast, colon and skin. Cancer care providers should consider recommendations to screen for vitamin D deficiency in this population.

Immune Response: A Missed Opportunity Between Vitamin D and Radiotherapy

Radiotherapy (RT) is a mainstay treatment in several types of cancer and acts by mediating various forms of cancer cell death, although it is still a large challenge to enhance therapy efficacy. Radiation resistance represents the main cause of cancer progression, therefore, overcoming treatment resistance is now the greatest challenge for clinicians. Increasing evidence indicates that immune response plays a role in reprogramming the radiation-induced tumor microenvironment (TME). Intriguingly, radiation-induced immunosuppression possibly overwhelms the ability of immune system to ablate tumor cells. This induces an immune equilibrium, which, we hypothesize, is an opportunity for radiosensitizers to make actions. Vitamin D has been reported to act in synergistic with RT by potentiating antiproliferative effect induced by therapeutics. Additionally, vitamin D can also regulate the TME and may even lead to immunostimulation by blocking immunosuppression following radiation. Previous reviews have focused on vitamin D metabolism and epidemiological trials, however, the synergistic effect of vitamin D and existing therapies remains unknown. This review summarizes vitamin D mediated radiosensitization, radiation immunity, and vitamin D-regulated TME, which may contribute to more successful vitamin D-adjuvant radiotherapy.

Targeting mTOR by CZ415 Suppresses Cell Proliferation and Promotes Apoptosis via Lipin-1 in Cervical Cancer In Vitro and In Vivo

CZ415, a novel inhibitor of mammalian target of rapamycin (mTOR) kinase, has demonstrated anti-tumor activity in several types of cancer. However, its biological function and underlying mechanism of action in cervical cancer (CC) have not been fully studied. Two CC cell lines (Hela and Siha) were treated with increasing concentrations of CZ415. Cell viability was tested with the CCK-8 assay, cell proliferation was determined by Edu staining and the colony formation assay, and apoptosis was determined by flow cytometry and Hoechst 33342 staining. Protein expression was evaluated by western blotting. A nude mouse xenograft model was used to confirm the anti-tumor activity of CZ415 in vivo. Hematoxylin and eosin (H&E) and immunohistochemistry (IHC) staining were performed on samples of tumor tissue. Results showed that CZ415 inhibited CC cell survival in a dose- and time-dependent manner, and 100 nanomolar and 48 h were the optimal conditions. In vitro and in vivo experiments showed that treatment with CZ415 significantly inhibited spheroid formation, cell proliferation, and tumor growth. Further studies showed that the anti-cancer effects of CZ415 were due to an induction of apoptosis, which was accompanied by an upregulation of Bax and downregulation of Bcl-2 through Lipin-1. CZ415 also reduced the levels of mTOR/STAT3 expression. However, these phenotypic changes were reversed by overexpression of Lipin-1. Our results suggest that the novel mTOR inhibitor CZ415 mediates tumor malignancy via Lipin-1 and might be useful for treating CC.

Wnt and Vitamin D at the Crossroads in Solid Cancer

Simple Summary

The Wnt/β-catenin signaling pathway is aberrantly activated in most colorectal cancers and less frequently in a variety of other solid neoplasias. Many epidemiological and experimental studies and some clinical trials suggest an anticancer action of vitamin D, mainly against colorectal cancer. The aim of this review was to analyze the literature supporting the interference of Wnt/β-catenin signaling by the active vitamin D metabolite 1α,25-dihydroxyvitamin D₃. We discuss the molecular mechanisms of this antagonism in colorectal cancer and other cancer types. Additionally, we summarize the available data indicating a reciprocal inhibition of vitamin D action by the activated Wnt/β-catenin pathway. Thus, a complex mutual antagonism between Wnt/β-catenin signaling and the vitamin D system seems to be at the root of many solid cancers.

Abstract

Abnormal activation of the Wnt/β-catenin pathway is common in many types of solid cancers. Likewise, a large proportion of cancer patients have vitamin D deficiency. In line with these observations, Wnt/β-catenin signaling and 1α,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃), the active vitamin D metabolite, usually have opposite effects on cancer cell proliferation and phenotype. In recent years, an increasing number of studies performed in a variety of cancer types have revealed a complex crosstalk between Wnt/β-catenin signaling and 1,25(OH)₂D₃. Here we review the mechanisms by which 1,25(OH)₂D₃ inhibits Wnt/β-catenin signaling and, conversely, how the activated Wnt/β-catenin pathway may abrogate vitamin D action. The available data suggest that interaction between Wnt/β-catenin signaling and the vitamin D system is at the crossroads in solid cancers and may have therapeutic applications.

WNT/β-catenin signaling in the development of liver cancers

The WNT/β-catenin signaling pathway is a highly conserved and tightly controlled molecular mechanism that regulates embryonic development, cellular proliferation and differentiation. Of note, accumulating evidence has shown that the aberrant of WNT/β-catenin signaling promotes the development and/or progression of liver cancer, including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), the two most prevalent primary liver tumours in adults. There are two different WNT signaling pathways have been identified, which were termed non-canonical and canonical pathways, the latter involving the activation of β-catenin. β-catenin, acting as an intracellular signal transducer in the WNT signaling pathway, is encoded by CTNNB1 and plays a critical role in tumorigenesis. In the past research, most liver tumors have mutations in genes encoding key components of the WNT/β-catenin signaling pathway. In addition, several of other signaling pathways also can crosswalk with β-catenin. In this review, we discuss the most relevant molecular mechanisms of action and regulation of WNT/β-catenin signaling in the development and pathophysiology of liver cancers, as well as in the development of therapeutics.

Nature-derived compounds modulating Wnt/ -catenin pathway: a preventive and therapeutic opportunity in neoplastic diseases

The Wnt/β-catenin signaling is a conserved pathway that has a crucial role in embryonic and adult life. Dysregulation of the Wnt/β-catenin pathway has been associated with diseases including cancer, and components of the signaling have been proposed as innovative therapeutic targets, mainly for cancer therapy. The attention of the worldwide researchers paid to this issue is increasing, also in view of the therapeutic potential of these agents in diseases, such as Parkinson's disease (PD), for which no cure is existing today. Much evidence indicates that abnormal Wnt/β-catenin signaling is involved in tumor immunology and the targeting of Wnt/β-catenin pathway has been also proposed as an attractive strategy to potentiate cancer immunotherapy. During the last decade, several products, including naturally occurring dietary agents as well as a wide variety of products from plant sources, including curcumin, quercetin, berberin, and ginsenosides, have been identified as potent modulators of the Wnt/β-catenin signaling and have gained interest as promising candidates for the development of chemopreventive or therapeutic drugs for cancer. In this review we make an overview of the nature-derived compounds reported to have antitumor activity by modulating the Wnt/β-catenin signaling, also focusing on extraction methods, chemical features, and bio-activity assays used for the screening of these compounds.

Vitamin D-Induced Molecular Mechanisms to Potentiate Cancer Therapy and to Reverse Drug-Resistance in Cancer Cells

Increasing interest in studying the role of vitamin D in cancer has been provided by the scientific literature during the last years, although mixed results have been reported. Vitamin D deficiency has been largely associated with various types of solid and non-solid human cancers, and the almost ubiquitous expression of vitamin D receptor (VDR) has always led to suppose a crucial role of vitamin D in cancer. However, the association between vitamin D levels and the risk of solid cancers, such as colorectal, prostate and breast cancer, shows several conflicting results that raise questions about the use of vitamin D supplements in cancer patients. Moreover, studies on vitamin D supplementation do not always show improvements in tumor progression and mortality risk, particularly for prostate and breast cancer. Conversely, several molecular studies are in agreement about the role of vitamin D in inhibiting tumor cell proliferation, growth and invasiveness, cell cycle arrest and inflammatory signaling, through which vitamin D may also regulate cancer microenvironment through the activation of different molecular pathways. More recently, a role in the regulation of cancer stem cells proliferation and short non-coding microRNA (miRNAs) expression has emerged, conferring to vitamin D a more crucial role in cancer development and progression. Interestingly, it has been shown that vitamin D is able not only to potentiate the effects of traditional cancer therapy but can even contribute to overcome the molecular mechanisms of drug resistance—often triggering tumor-spreading. At this regard, vitamin D can act at various levels through the regulation of growth of cancer stem cells and the epithelial–mesenchymal transition (EMT), as well as through the modulation of miRNA gene expression. The current review reconsiders epidemiological and molecular literature concerning the role of vitamin D in cancer risk and tumor development and progression, as well as the action of vitamin D supplementation in potentiating the effects of drug therapy and overcoming the mechanisms of resistance often triggered during cancer therapies, by critically addressing strengths and weaknesses of available data from 2010 to 2020.

Vitamin D in Triple-Negative and BRCA1-Deficient Breast Cancer-Implications for Pathogenesis and Therapy

Several studies show that triple-negative breast cancer (TNBC) patients have the lowest vitamin D concentration among all breast cancer types, suggesting that this vitamin may induce a protective effect against TNBC. This effect of the active metabolite of vitamin D, 1α,25-dihydroxyvitamin D3 (1,25(OH)2D), can be attributed to its potential to modulate proliferation, differentiation, apoptosis, inflammation, angiogenesis, invasion and metastasis and is supported by many in vitro and animal studies, but its exact mechanism is poorly known. In a fraction of TNBCs that harbor mutations that cause the loss of function of the DNA repair-associated breast cancer type 1 susceptibility (BRCA1) gene, 1,25(OH)2D may induce protective effects by activating its receptor and inactivating cathepsin L-mediated degradation of tumor protein P53 binding protein 1 (TP53BP1), preventing deficiency in DNA double-strand break repair and contributing to genome stability. Similar effects can be induced by the interaction of 1,25(OH)2D with proteins of the growth arrest and DNA damage-inducible 45 (GADD45) family. Further studies on TNBC cell lines with exact molecular characteristics and clinical trials with well-defined cases are needed to determine the mechanism of action of vitamin D in TNBC to assess its preventive and therapeutic potential.

Chemical evolution for taming the 'pathogenic kinase' PAK1

•

PAK1 is the major ‘pathogenic’ kinase.

•

Several potent PAK1 blockers developed are introduced for treatment of a wide variety of PAK1-dependent diseases including cancers and pandemic COVID-19 infection.

To celebrate the 25th anniversary of the cloning of the first mammalian p21-activated kinases (PAKs) (RAC/CDC42-activated kinases) by Ed Manser, the first international PAK symposium was held in NYC in October 2019. Among six distinct PAKs in mammals, PAK1 is the major ‘pathogenic kinase’, the abnormal activation of which is responsible for a wide variety of diseases and disorders including cancers, ageing processes and infectious and inflammatory diseases such as pandemic coronaviral infection. Recently, for a clinical application, a few potent (highly cell-permeable and water-soluble) PAK1 blockers have been developed from natural or synthetic PAK1 blockers (triptolide, vitamin D3 and ketorolac) via a series of ‘chemical evolutions’ that boost pharmacological activities >500 times.

Calcipotriol Inhibits NLRP3 Signal Through YAP1 Activation to Alleviate Cholestatic Liver Injury and Fibrosis

Cholestasis is common in multiple clinical circumstances. The NOD-like receptor protein 3 (NLRP3) inflammasome pathway has been demonstrated to play an important role in liver injury and fibrosis induced by cholestasis. We previously proved that MCC950, a selective NLRP3 inhibitor, alleviates liver fibrosis and injury in experimental liver cholestasis induced by bile-duct ligation (BDL) in mice. Herein, we investigate the role of calcipotriol, a potent vitamin D receptor agonist, in experimental liver cholestasis, test its therapeutic efficacy, and explore its potential protective mechanism. C57BL/6 mice were made to undergo BDL or fed the 0.1% 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet to establish two classic cholestatic models. Calcipotriol was administered intraperitoneally to these mice daily. Serum makers of liver damage and integrity, liver histological changes, levels of liver pro-fibrotic markers, bile acid synthetases and transporters were measured in vivo. The underlying mechanism by which calcipotriol alleviates cholestatic liver injury and fibrosis was further investigated. The results of the current study demonstrated that calcipotriol supplement significantly alleviate cholestatic liver injury and fibrosis. Moreover, calcipotriol supplement markedly inhibited NLRP3 inflammasome pathway activation to alleviate liver injury and fibrosis in vivo and inhibit hepatic stellate cell (HSC) activation in vitro. In addition, VDR agonist calcipotriol exert inhibitory effect on NLRP3 inflammasome activation through activating yes-associated protein 1 (YAP1). In conclusion, our findings proved that calcipotriol suppressed the NLRP3 signal by activating YAP1 to alleviate liver injury and retard fibrogenesis in cholestasis.

CD133 in Breast Cancer Cells: More than a Stem Cell Marker

Initially correlated with hematopoietic precursors, the surface expression of CD133 was also found in epithelial and nonepithelial cells from adult tissues in which it has been associated with a number of biological events. CD133 is expressed in solid tumors as well, including breast cancer, in which most of the studies have been focused on its use as a surface marker for the detection of cells with stem-like properties (i.e., cancer stem cells (CSCs)). Differently with other solid tumors, very limited and in part controversial are the information about the significance of CD133 in breast cancer, the most common malignancy among women in industrialized countries. In this review, we summarize the latest findings about the implication of CD133 in breast tumors, highlighting its role in tumor cells with a triple negative phenotype in which it directly regulates the expression of proteins involved in metastasis and drug resistance. We provide updates about the prognostic role of CD133, underlining its value as an indicator of increased malignancy of both noninvasive and invasive breast tumor cells. The molecular mechanisms at the basis of the regulation of CD133 levels in breast tumors have also been reviewed, highlighting experimental strategies capable to restrain its level that could be taken into account to reduce malignancy and/or to prevent the progression of breast tumors.

Nuclear Receptors Are Differentially Expressed and Activated in KAIMRC1 Compared to MCF7 and MDA-MB231 Breast Cancer Cells

We recently established a KAIMRC1 cell line that has unique features compared to the known breast cancer cell lines, MCF7 and MDA-MB231. To characterize it further, we investigated the expression profile of nuclear receptors and their respective co-factors in these cell lines. We confirm that in contrast to the triple negative cell line MDA-MB231, the MCF7 and KAIMRC1 are estrogen receptor alpha (ERa) and progesterone receptor alpha (PRa) positive, with significant lower expression of these receptors in KAIMRC1. KAIMRC1 cell is a vitamin D receptor (VDR) negative and V-ErbA-Related Protein 2 (EAR2) positive in contrast to MCF7 and MDA-MB231. Remarkably, the histone deacetylases (HDACs) are highly expressed in KAIRMC1 with HDAC6 and HDAC 7 are exclusively expressed in KAIMRC1 while thyroid hormone receptor-associated protein 80 (TRAP80), telomeric DNA binding protein 1 (TBP1) and TGF-beta receptor interacting protein (TRIP1) are absent in KAIMRC1 but present in MCF7 and MDA-MB231. In a luciferase reporter assay, the ERa coexpression is needed for estrogen receptor element (ERE)-luciferase activation by estradiol in KAIMRC1 but not in MCF7. The co-expression of exogenous Liver X receptor alpha (LXRa)/retinoid X receptor alpha (RXRa) are necessary for LXR responsive element (LXRE) activation by the GW3696 in the three cell lines. However, the activity of peroxisome proliferator-activated receptor response element (PPARE)-tk-luciferase reporter increased when peroxisome proliferator-activated receptors alpha (PPARa)/RXRa were coexpressed but the addition of PPARa agonist (GW7647) did not stimulate further the reporter. The signal of the PPARE reporter increased in a dose-dependent manner with rosiglitazone (PPARg agonist) in KAIMRC1, MCF7, and MDA-MB231 when the proliferator-activated receptors gamma (PPARg)/RXRa receptors were cotransfected. Retinoic acid-induced activation of retinoic acid receptor response element (RARE)-tk-luciferase is dependent on exogenous expression of retinoic acid receptor alpha (RARa)/RXRa heterodimer in MDA-MB 231 but not in MCF7 and KAIMRC1 cell lines. In the three cell lines, Bexarotene-induced retinoid X receptor response element (RXRE)-luciferase reporter activation was induced only if the RXRa/LXRa heterodimer were co-expressed. The vitamin D receptor response element (VDRE)-luciferase reporter activity showed another distinct feature of KAIMRC1, where only co-expression of exogenous vitamin D receptor (VDR)/RXRa heterodimer was sufficient to reach the maximum rate of activation of VDRE reporter. In the proliferation assay, nuclear receptors ligands showed a distinct effect on KAIMRC1 compared to MCF7 and MDA-MB231. Growth inhibition effects of used ligands suggest that KAIMRC1 correlate more closely to MDA-MB231 than MCF7. Vitamin D3, rosiglitazone, novel RXR compound (RXRc) and PPARa compound (GW6471) have the most profound effects. In conclusion, we showed that nuclear receptors are differentially expressed, activated and also their ligand produced distinct effects in KAIMRC1 compared to MCF7 and MDA-MB231. This finding gives us confidence that KAIMRC1 has a unique biological phenotype.