Silencing of BACH1 inhibits invasion and migration of prostate cancer cells by altering metastasis-related gene expression.

BACKGROUND: Cancer lethality is mainly caused by metastasis. Therefore, understanding the nature of the genes involved in this process has become a priority. BACH1, a basic leucine zipper transcription factor, has been shown to transcriptionally regulate expression of a range of genes that are associated with breast cancer metastasis. However, the exact role and the underlying molecular mechanism of BACH1 in prostate cancer remain unclear. This study aims to explore the expression of BACH1 in prostate cancer tissues and the effect of BACH1 suppression on prostate cancer cell behavior. MATERIALS AND METHODS: In this study, we used quantitative real-time PCR (qRT-PCR) to measure BACH1 expression in prostate adenocarcinoma tissues and two metastasis-derived prostate cancer cell lines, DU145 and LNCaP. We also used immunohistochemical (IHC) staining to measure BACH1 protein expression in prostate adenocarcinoma and matched normal tissue samples. In the following BACH1 expression was silenced in DU145 cells using siRNA as well. Knockdown was confirmed by qRT-PCR and Western blotting. The cytotoxic effects of BACH1-siRNA on DU145 cells were determined using an MTT assay. The migration and invasive capacity of DU145 cells were examined by scratch wound healing assay and matrigel invasion assay, respectively. We also used qRT-PCR to study the effect of BACH1 silencing on the expression levels of metastasis-related genes. RESULTS: We find that the expression of BACH1 mRNA and protein in prostate cancer tissues is significantly higher than in matched normal prostate tissues (p < .05). In addition, DU145 and LNCaP cells exhibited 4.25-fold and 3.45-fold higher levels of BACH1 compared to HFF cell line. BACH1-siRNA significantly reduced both mRNA and protein expression levels in DU145 cells. More importantly, we show that BACH1 promotes key features of metastasis, as BACH1-siRNA treatment significantly reduced cell invasion and migration by changing the expression levels of a number of metastasis-related genes in vitro. CONCLUSIONS: BACH1 is overexpressed in prostate cancer. Because this promotes invasion and migration, it may facilitate metastasis of prostate cancer. Thus, BACH1 is a potential therapeutic target for metastatic prostate cancer. BACH1 silencing therapy can be considered as a novel and effective adjuvant in prostate cancer targeted therapies.

The Different Mechanisms of Cancer Drug Resistance: A Brief Review.

Anticancer drugs resistance is a complex process that arises from altering in the drug targets. Advances in the DNA microarray, proteomics technology and the development of targeted therapies provide the new strategies to overcome the drug resistance. Although a design of the new chemotherapy agents is growing quickly, effective chemotherapy agent has not been discovered against the advanced stage of cancer (such as invasion and metastasis). The cancer cell resistance against the anticancer agents can be due to many factors such as the individual's genetic differences, especially in tumoral somatic cells. Also, the cancer drug resistance is acquired, the drug resistance can be occurred by different mechanisms, including multi-drug resistance, cell death inhibiting (apoptosis suppression), altering in the drug metabolism, epigenetic and drug targets, enhancing DNA repair and gene amplification. In this review, we outlined the mechanisms of cancer drug resistance and in following, the treatment failures by common chemotherapy agents in the different type of cancers.

Overcoming the Challenges of siRNA Delivery: Nanoparticle Strategies.

BACKGROUND: Despite therapeutics based on siRNA have an immense potential for the treatment of incurable diseases such as cancers. However, the in vivo utilization of siRNA and also the delivery of this agent to the target site is one of the most controversial challenges. The helpful assistance by nanoparticles can improve stable delivery and also enhance efficacy. More nanoparticle-based siRNA therapeutics is expected to become available in the near future. METHODS: The search strategy followed the guidelines of the Centre of Reviews and Dissemination. The studies were identified from seven databases (Scopus, Web of Science, Academic Search Premiere, CINAHL, Medline Ovid, Eric and Cochrane Library). Studies was selected based on titles, abstracts and full texts. RESULTS: One hundred twenty nine papers were included in the review. These papers defined hurdles in RNAi delivery and also strategies to overcome these hurdles. This review discussed the existing hurdles for systemic administration of siRNA as therapeutic agents and highlights the various strategies to overcome these hurdles, including lipid-based nanoparticles and polymeric nanoparticles, and we also briefly reviewed chemical modification. CONCLUSION: Delivery of siRNA to the target site is the biggest challenge for its application in the clinic. The findings of this review confirmed by encapsulation siRNA in the nanoparticles can overcome these challenges. The rapid progress in nanotechnology has enabled the development of effective nanoparticles as the carrier for siRNA delivery. However, our data about siRNA-based therapeutics and also nanomedicine are still limited. More clinical data needs to be completely understood in the benefits and drawbacks of siRNA-based therapeutics. Prospective studies must pay attention to the in vivo safety profiles of the different delivery systems, including uninvited immune system stimulation and cytotoxicity. In essence, the development of nontoxic, biocompatible, and biodegradable delivery systems for medical application of RNAi-based therapeutics is needed.

BACH1 silencing by siRNA inhibits migration of HT-29 colon cancer cells through reduction of metastasis-related genes.

BACKGROUND: Metastasis to distant organs is a hallmark of many tumor cells. BACH1 (BTB and CNC homology 1) is a transcriptional factor which promotes the migration and invasion of breast cancer cells. BACH1 expression and its target genes are intimately associated with the metastasis possibility of clinical samples, and BACH1 reduction leads to meaningful depletion in metastasis. The evaluation of BACH1 role in colon cancer remains elusive. This study seeks to further investigate the role of BACH1 in colon cancer cells. METHODS: Quantitative RT-PCR (qRT-PCR) was used to detect BACH1 expression and other related metastatic genes following siRNA knockdown in colon cancer HT-29 cells. And the protein level assessed by Western blot. MTT assay was to measure the changed cell viability after BACH1 siRNA transfection. Scratch-wound motility assays measured capacity of tumor cell migration of HT-29 cells after BACH1 silencing. RESULTS: The inhibitory effect of BACH1 was performed by siRNA knockdown using highly metastatic HT-29 colon cell lines. Quantitative RT-PCR and Western blot analysis revealed that the expression levels of BACH1 mRNA and protein in HT29 cells were significantly suppressed after transfection. Conversely, the BACH1 expression increased migration. Also the CXCR4 and MMP1 expression levels decreased following BACH1 knockdown in HT-29 cells. CONCLUSION: Our results indicated that BACH1 down-regulation in HT29 CRC cells had no effect on cell growth but did inhibit cell migration by decreasing metastasis-related genes expression. Collectively, these results suggest that BACH1 may function as an oncogenic driver in colon cancer and may represent as a potential target of gene therapy for CRC treatment.

BACH1, the master regulator gene: A novel candidate target for cancer therapy.

BACH1 (BTB and CNC homology 1, basic leucine zipper transcription factor 1) is a transcriptional factor and a member of cap 'n' collar (CNC) and basic region leucine zipper factor family. In contrast to other bZIP family members, BACH1 appeared as a comparatively specific transcription factor. It acts as transcription regulator and is recognized as a recently hypoxia regulator and functions as an inducible repressor for the HO-1 gene in many human cell types in response to stress oxidative. In regard to studies lately, although, BACH1 has been related to the regulation of oxidative stress and heme oxidation, it has never been linked to invasion and metastasis. Recent studies have showed that BACH1 is involved in bone metastasis of breast cancer by up-regulating vital metastatic genes like CXCR4 and MMP1. This newly discovered aspect of BACH1 gene provides new insight into cancer progression study and stands on its master regulator role in metastasis process, raising the possibility of considering it as a potential target for cancer therapy.

The Herbal Medicine Utrica Dioica Inhibits Proliferation of Colorectal Cancer Cell Line by Inducing Apoptosis and Arrest at the G2/M Phase.

BACKGROUND: One of the major causes of cancer death internationally and the third most prevalent cancer in the world has been diagnosed with colorectal cancer. Although current routine treatments of cancer have been successful in some extent, mortality caused by adverse effects of these strategies is still raising. Medicinal plants are potential sources of anticancer compounds and can be exploited as a powerful complementary tool. This study aimed to investigate the cytotoxic effects of nettle extract on mouse colorectal cancer cells, HCT. MATERIALS AND METHODS: In the present study, to evaluate the cytotoxicity of nettle extract, MTT assay and trypan blue were performed. Subsequently, DNA fragmentation and TUNEL test was carried out for determination of apoptosis. Real-time PCR test was used to quantify the expression of Caspase-3, Caspase-9, and Bcl-2 which is involved in apoptosis regulation. Finally, cell cycle analysis was conducted by using flow cytometry. RESULTS: The results of MTT assay showed that the dichloromethane extract of U. dioica extract significantly destroyed cancer cells HCT-116. DNA fragmentation and TUNEL test demonstrated that Utrica extract elicited apoptotic response in the cancer cells. The messenger RNA (mRNA) expression levels of Caspase-3 and Caspase-9 markedly increased, while the Bcl-2 gene was conversely downregulated. Findings of flow cytometry confirmed that cell cycle arrest has occurred at the G2 phase. CONCLUSION: Taken together, our experiment showed that subjecting HCT-116 cells to dichloromethane extract of nettle (U. dioica), increases turnover of these cells. Thus, it may be a useful agent in the treatment of colorectal cancer.