Integrated transcriptome interactome study of oncogenes and tumor suppressor genes in breast cancer

The effect of human umbilical cord mesenchymal stem cells conditioned medium combined with tamoxifen drug on BRCA1 and BRCA2 expression in breast cancer mouse models

BACKGROUND

A growing number of studies has indicated that the expression of Breast Cancer Susceptibility Genes 1 (BRCA1) and BRCA2 contribute to the resistance to DNA-damaging chemotherapies. Tamoxifen induces tumor cell death by suppressing estrogen receptor (ER) signaling and inducing DNA damage, and BRCA1 upregulation causes Tamoxifen chemoresistance in breast cancer cells. Consequently, this research study aimed to investigate the possible therapeutic effect of Human Umbilical Cord Mesenchymal Stem Cells Conditioned Medium (UCMSCs-CM) on sensitizing breast cancer cells to Tamoxifen by regulating BRCA1 and BRCA2 expression in vivo.

METHODS

Forty female mice, 4-8 weeks old, with weight of 150 g, were used for this study. Mouse 4T1 breast tumor models were established and then treated with UCMSCs-CM and Tamoxifen alone or in combination. After 10 days, the tumor masses were collected and the expression levels of BRCA1 and BRCA2 were evaluated using qRT-PCR assay.

RESULTS

The results obtained from qRT-PCR assay illustrated that UCMSCs-CM, either alone or in combination with Tamoxifen, significantly downregulated the mRNA expression levels of BRCA1 in breast cancer mouse models. However, both UCMSCs-CM and Tamoxifen indicated no statistically significant impact on BRCA2 mRNA expression compared to controls.

CONCLUSION

Our findings evidenced that UCMSCs-CM could be considered as a potential therapeutic option to modulate Tamoxifen chemosensitivity by regulating BRCA1 in breast cancer.

Curcumin alters distinct molecular pathways in breast cancer subtypes revealed by integrated miRNA/mRNA expression analysis

BACKGROUND

Curcumin is well known for its anticancer properties. Its cytotoxic activity has been documented in several cancer cell lines, including breast cancer. The pleiotropic activity of curcumin as an antioxidant, an antiangiogenic, antiproliferative, and pro-apoptotic, is due to its diverse targets, such as signaling pathways, protein/enzyme, or noncoding gene.

AIM

This study aimed to identify key miRNAs and mRNAs induced by curcumin in breast cancer cells MCF7, T47D (hormone positive), versus MDA-MB231 (hormone negative) using comparative analysis of global gene expression profiles.

METHODS

RNA was isolated and subjected to mRNA and miRNA library sequencing to study the global gene expression profile of curcumin-treated breast cancer cells. The differential expression of gene and miRNA was performed using the DESeq R package. The enriched pathways were studied using cluster profileR, and integrated miRNA-mRNA analysis was carried out using miRtarvis and miRmapper tools.

RESULTS

Curcumin treatment led to upregulation of 59% TSGs in MCF7, 21% in MDA-MB-231 cells, and 36% TSGs in T47D, and downregulation of 57% oncogenes in MCF7, 76% in MDA-MB-231, and 91% in T47D. Similarly, curcumin treatment led to upregulation of 32% TSmiRs in MCF7, 37.5% in MDA-MB231, and 62.5% in T47D, and downregulation of 77% oncomiRs in MCF7, 50% in MDA-MB231 and 28.6% in T47D. Integrated analysis of miRNA-mRNA led to the identification of a common NFKB pathway altered by curcumin in all three cell lines. Analysis of uniquely enriched pathway revealed non-integrin membrane-ECM interactions and laminin interactions in MCF7; extracellular matrix organization and degradation in MDA-MB-231 and cell cycle arrest and G2/M transition in T47D.

CONCLUSION

Curcumin regulates miRNA and mRNA in a cell type-specific manner. The integrative analysis led to the detection of miRNAs and mRNAs pairs, which can be used as biomarkers associated with carcinogenesis, diagnostic, and treatment response in breast cancer.

Allicin induces cell cycle arrest and apoptosis of breast cancer cells in vitro via modulating the p53 pathway

BACKGROUND

The tumor suppressor protein p53 is a most promising target for the development of anticancer drugs. Allicin (diallylthiosulfinate) is one of the most active components of garlic (Alliium sativum L.) and possesses a variety of health-promoting properties with pharmacological applications. However, whether allicin plays an anti-cancer role against breast cancer cells through the induction of p53-mediated apoptosis remains unknown.

METHODS AND RESULTS

In this study, we investigate the anti-breast cancer effect of allicin in vitro by using MCF-7 and MD-MBA-231 cells. We found that allicin reduces cell viability, induces apoptosis and cell cycle arrest in both cells. Allicin activated p53 and caspase 3 expressions in both cells but produced different effects on the expression of p53-related biomarkers. In MDA-MB-231 cells, allicin up-regulated the mRNA and protein expression of A1BG and THBS1 while down-regulated the expression of TPM4. Conversely, the mRNA and protein expression of A1BG, THBS1 and TPM4 were all reduced in MCF-7 cells. Hence, allicin induces cell cycle arrest and apoptosis in breast cancer cells through p53 activation but it effects on the expression of p53-related biomarkers were dependent upon the specific type of breast cancer involved.

CONCLUSIONS

These findings suggest that allicin induces apoptosis and regulates biomarker expression in breast cancer cell lines through modulating the p53 signaling pathway. Furthermore, our results promote the utility of allicin as compound for further studies as an anticancer drug targeting p53.

The genomic architecture of metastasis in breast cancer: focus on mechanistic aspects, signalling pathways and therapeutic strategies

Breast cancer is a multifactorial, heterogeneous disease and the second most frequent cancer amongst women worldwide. Metastasis is one of the most leading causes of death in these patients. Early-stage or locally advanced breast cancer is limited to the breast or nearby lymph nodes. When breast cancer spreads to farther tissues/organs from its original site, it is referred to as metastatic or stage IV breast cancer. Normal breast development is regulated by specific genes and signalling pathways controlling cell proliferation, cell death, cell differentiation and cell motility. Dysregulation of genes involved in various signalling pathways not only leads to the formation of primary tumour but also to the metastasis as well. The metastatic cascade is represented by a multi-step process including invasion of the local tumour cell followed by its entry into the vasculature, exit of malignant cells from the circulation and ultimately their colonization at the distant sites. These stages are referred to as formation of primary tumour, angiogenesis, invasion, intravasation and extravasation, respectively. The major sites of metastasis of breast cancer are the lymph nodes, bone, brain and lung. Only about 28% five-year survival rate has been reported for stage IV breast cancer. Metastasis is a serious concern for breast cancer and therefore, various therapeutic strategies such as tyrosine kinase inhibitors have been developed to target specific dysregulated genes and various signalling pathways involved in different steps of metastasis. In addition, other therapies like hyperbaric oxygen therapy, RNA interference and CRISPR/Cas9 are also being explored as novel strategies to cure the stage IV/metastatic breast cancer. Therefore, the current review has been compiled with an aim to evaluate the genetic basis of stage IV breast cancer with a focus on the molecular mechanisms. In addition, the therapeutic strategies targeting these dysregulated genes involved in various signalling pathways have also been discussed. Genome editing technologies that can target specific genes in the affected areas by making knock-in and knock-out alternations and thereby bring significant treatment outcomes in breast cancer have also been summarized.

Circulating miRNAs as early indicators of diet and physical activity response in women with metastatic breast cancer

Treatments for metastatic breast cancer (MBC) improve survival but often impose prolonged symptom burden. We performed molecular characterization of 84 miRNAs in the circulating serum of women with MBC to explore possible early indicators of intervention response. Expression levels of miR-10a-5p and miR-211-5p were downregulated in nonresponders, but upregulated in responders (miR-10a-5p: 0.40-fold and eightfold; miR 211-5p: 0.47-fold and fourfold). miR-205-5p expression was upregulated in both nonresponders and responders, but to a greater extent in responders (1.8-fold and sixfold). Additionally, levels of miR-10a-5p were negatively correlated with expression levels of IL-6 (r = -0.412). Exploration of these pathways may reveal mechanisms of action in lifestyle interventions aimed at improving quality of life and impacting disease progression for women with MBC.

As treatment for women with metastatic breast cancer improves survival rates, interventions are needed that relieve symptom burden. We examined the serum of women with metastatic breast cancer who participated in a lifestyle intervention that improved diet and increased physical activity. Three miRNAs were discovered that may serve as early indicators of the ability of lifestyle interventions to improve quality of life and impact disease progression.

Three miRNAs may predict how women with metastatic breast cancer respond to lifestyle interventions.

Design, synthesis and biological evaluation of water soluble and non-aggregated silicon phthalocyanines, naphthalocyanines against A549, SNU-398, SK-MEL128, DU-145, BT-20 and HFC cell lines as potential anticancer agents

Cancer has become an important public problem in worldwide since cancer incidence and mortality are growing rapidly. In this study, water soluble and non-aggregated silicon (IV) phthalocyanines and naphthalocyanines containing (3,5-bis{3-[3-(diethylamino)phenoxy]propoxy}phenyl)methoxy groups have been synthesized and characterized to investigate their anticancer potential. Their DNA binding/nuclease, topoisomerases inhibition were investigated using UV-Vis absorption, thermal denaturation and agarose gel electrophoresis. The in vitro cytotoxic properties of the compounds on human lung (A549), breast (BT-20), liver (SNU-398), prostate (DU-145), melanoma (SK-Mel 128) carcinoma and human fibroblast (HFC) normal cell lines were evaluated by using MTT assay. In order to determine the mechanism of cancer cell growth suppression, cell cycle analysis was carried out using flow cytometer on A549 cell line. The K_b values of SiPc1a and SiNc2a were 6.85 ± (0.35) × 10⁶ and 1.72 ± (0.16) × 10⁴ M^-1 and T_m values of ct-DNA were calculated as 82.02 °C and 78.07 °C, respectively in the presence of both compounds. The Δ_Tm values of SiPc1a and SiNc2a were calculated as 6.45 and 2.50 °C, respectively. The nuclease effects of SiPc1a and SiNc2a with supercoiled plasmid pBR322 DNA demonstrated that both compounds did not trigger any DNA nuclease effects at the lowest concentrations without irradiation whereas both compounds in the presence of activating agent (H₂O₂) showed significant plasmid DNA nuclease actions under irradiation (22.5 J/cm²). SiPc1a and SiNc2a inhibited to topoisomerase I on increasing concentrations whilst they had lower inhibition action toward topoisomerase II that of topoisomerase I. The in vitro cytotoxicity studies displayed that SiPc1a had the highest cytotoxic effects among the tested compounds against A549, SNU-398, SK-MEL128, DU-145, BT-20 and HFC cell lines with CC₅₀ values ranged from 0.49 to 2.99 µM. Furthermore, SiPc1a inhibited cell proliferation by cell cycle arrest in G₀/G₁ phase. All of these results suggested that SiPc1a is a promising candidate as an anticancer agent.

Forkhead box P3 promotes breast cancer cell apoptosis by regulating programmed cell death 4 expression

Forkhead box P3 (FOXP3), an X-linked tumor suppressor gene, plays an important role in breast cancer. However, the biological functions of FOXP3 in breast cancer apoptosis remain unclear. To investigate the underlying genes and networks regulated by FOXP3 in breast cancer, RNA sequencing was performed to compare FOXP3-overexpressing MDA-MB-231 cells and control MDA-MB-231 cells. Differentially expressed genes were identified, and functional enrichment analysis comparing the two groups was performed. The differentially expressed genes were mainly enriched in phagosomes, oxytocin, serotonergic synapses and the phospholipase D signaling pathway. Furthermore, gene set enrichment analysis revealed the enrichment of a gene signature associated with apoptosis in FOXP3-overexpressing MDA-MB-231 cells compared with wild-type cells. Further analysis showed that programmed cell death 4 (PDCD4), a key molecule involved in apoptosis, was overexpressed in FOXP3-MDA-MB-231 cells. Reverse transcription-quantitative PCR and western blotting showed that FOXP3 upregulated the expression of PDCD4 in breast cancer cells. Clinical sample analysis using a public database showed that the expression level of PDCD4 was associated with breast cancer clinical stages. Overall, the present study suggested that FOXP3 can promote the apoptosis of breast cancer cells by upregulating the expression of PDCD4, thus exerting a tumor suppressive function.

UDP-glucose 6-dehydrogenase knockout impairs migration and decreases in vivo metastatic ability of breast cancer cells

Dysregulated metabolism is a hallmark of cancer that supports tumor growth and metastasis. One understudied aspect of cancer metabolism is altered nucleotide sugar biosynthesis, which drives aberrant cell surface glycosylation known to support various aspects of cancer cell behavior including migration and signaling. We examined clinical association of nucleotide sugar pathway gene expression and found that UGDH, encoding UDP-glucose 6-dehydrogenase which catalyzes production of UDP-glucuronate, is associated with worse breast cancer patient survival. Knocking out the mouse homolog Ugdh in highly-metastatic 6DT1 breast cancer cells impaired migration ability without affecting in vitro proliferation. Further, Ugdh-KO resulted in significantly decreased metastatic capacity in vivo when the cells were orthotopically injected in syngeneic mice. Our experiments show that UDP-glucuronate biosynthesis is critical for metastasis in a mouse model of breast cancer.

Gender Differential Transcriptome in Gastric and Thyroid Cancers

Cancer has an important and considerable gender differential susceptibility confirmed by several epidemiological studies. Gastric (GC) and thyroid cancer (TC) are examples of malignancies with a higher incidence in males and females, respectively. Beyond environmental predisposing factors, it is expected that gender-specific gene deregulation contributes to this differential incidence. We performed a detailed characterization of the transcriptomic differences between genders in normal and tumor tissues from stomach and thyroid using Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) data. We found hundreds of sex-biased genes (SBGs). Most of the SBGs shared by normal and tumor belong to sexual chromosomes, while the normal and tumor-specific tend to be found in the autosomes. Expression of several cancer-associated genes is also found to differ between sexes in both types of tissue. Thousands of differentially expressed genes (DEGs) between paired tumor-normal tissues were identified in GC and TC. For both cancers, in the most susceptible gender, the DEGs were mostly under-expressed in the tumor tissue, with an enrichment for tumor-suppressor genes (TSGs). Moreover, we found gene networks preferentially associated to males in GC and to females in TC and correlated with cancer histological subtypes. Our results shed light on the molecular differences and commonalities between genders and provide novel insights in the differential risk underlying these cancers.

microR-505/heterogeneous nuclear ribonucleoprotein M inhibits hepatocellular carcinoma cell proliferation and induces cell apoptosis through the Wnt/β-catenin signaling pathway

Aim: This study aimed to investigate the expression of microRNA-505 (miR-505) and explore its clinical significance, biological function and mechanisms in hepatocellular carcinoma (HCC). Methods: Expression of miR-505 was measured in 128 paired HCC tissues and five cell lines by quantitative real-time polymerase chain reaction (qRT-PCR). MTT assay, Transwell migration, invasion assays and apoptosis assay were performed to explore the functional role of miR-505. The target gene of miR-505 was assessed using the bioinformatics assay and the related signaling pathway was confirmed using western blot. Results: Expression of miR-505 in HCC serum and tissues were downregulated. The overexpression of miR-505 in HCC cells inhibited cell proliferation and metastasis, as well as enhanced cell apoptosis by directly downregulating heterogeneous nuclear ribonucleoprotein M (HNRNPM). The activity of the Wnt/β-catenin signaling pathway was suppressed by the overexpression of miR-505 but was promoted by the upregulation of HNRNPM. Conclusion: The results suggest that the regulation of miR-505/HNRNPM may be a novel strategy to improve the targeted therapy of HCC.

Recent aspects of the effects of zinc on human health

Zinc (Zn) is one of the most important essential nutrients of great public health significance. It is involved in numerous biological functions and it is considered as a multipurpose trace element, due to its capacity to bind to more than 300 enzymes and more than 2000 transcriptional factors. Its role in biochemical pathways and cellular functions, such as the response to oxidative stress, homeostasis, immune responses, DNA replication, DNA damage repair, cell cycle progression, apoptosis and aging is significant. Zn is required for the synthesis of protein and collagen, thus contributing to wound healing and a healthy skin. Metallothioneins are metal-binding proteins and they are potent scavengers of heavy metals, including Zn, and protect the organism against stress. Zn deficiency is observed almost in 17% of the global population and affects many organ systems, leading to dysfunction of both humoral and cell-mediated immunity, thus increasing the susceptibility to infection. This review gives a thorough insight into the most recent evidence on the association between Zn biochemistry and human pathologies, epigenetic processes, gut microbial composition, drug targets and nanomedicine.

Therapeutic applications of CRISPR/Cas9 in breast cancer and delivery potential of gold nanomaterials

Globally, approximately 1 in 4 cancers in women are diagnosed as breast cancer (BC). Despite significant advances in the diagnosis and therapy BCs, many patients develop metastases or relapses. Hence, novel therapeutic strategies are required, that can selectively and efficiently kill malignant cells. Direct targeting of the genetic and epigenetic aberrations that occur in BC development is a promising strategy to overcome the limitations of current therapies, which target the tumour phenotype. The clustered regularly interspaced short palindromic repeats (CRISPR)/Cas system, composed of only an easily modifiable single guide RNA (sgRNA) sequence bound to a Cas9 nuclease, has revolutionised genome editing due to its simplicity and efficiency compared to earlier systems. CRISPR/Cas9 and its associated catalytically inactivated dCas9 variants facilitate the knockout of overexpressed genes, correction of mutations in inactivated genes, and reprogramming of the epigenetic landscape to impair BC growth. To achieve efficient genome editing in vivo, a vector is required to deliver the components to target cells. Gold nanomaterials, including gold nanoparticles and nanoclusters, display many advantageous characteristics that have facilitated their widespread use in theranostics, as delivery vehicles, and imaging and photothermal agents. This review highlights the therapeutic applications of CRISPR/Cas9 in treating BCs, and briefly describes gold nanomaterials and their potential in CRISPR/Cas9 delivery.