Bioengineered chimeric tRNA/pre-miRNAs as prodrugs in cancer therapy.

Today, biologic prodrugs have led to targeting specific tumor markers and have increased specificity and selectivity in cancer therapy. Various studies have shown the role of ncRNAs in cancer pathology and tumorigenesis and have suggested that ncRNAs, especially miRNAs, are valuable molecules in understanding cancer biology and therapeutic processes. Most miRNAs-based research and treatment are limited to chemically synthesized miRNAs. Synthetic alterations in these miRNA mimics may affect their folding, safety profile, and even biological activity. However, despite synthetic miRNA mimics produced by automated systems, various carriers could be used to achieve efficient production of bioengineered miRNAs through economical microbial fermentation. These bioengineered miRNAs as biological prodrugs could provide a new approach for safe therapeutic methods and drug production. In this regard, bioengineered chimeric miRNAs could be selectively processed to mature miRNAs in different types of cancer cells by targeting the desired gene and regulating cancer progression. In this article, we aim to review bioengineered miRNAs and their use in cancer therapy, as well as offering advances in this area, including the use of chimeric tRNA/pre-miRNAs.

Allogeneic tumor cell line-based vaccines: A good alternative to autologous and cancer stem cell vaccines in colorectal cancer.

OBJECTIVES: Besides the uncertainty about colorectal cancer stem cell (CCSC) markers, isolating, purifying, and enriching CCSCs to produce CCSC vaccines is highly challenging. However, allogeneic vaccines developed from CRC cell lines can provide universal, comprehensive, inexpensive, simple, and fast approach to cancer treatment. MATERIALS AND METHODS: CCSCs were isolated from human CRC tissue using the in vitro sphere formation assay and then characterized through gene expression analysis, in vivo and in vitro tumor formation assay, karyotyping, and surface marker detection. Subsequently, CCSCs and two CRC cell lines (HT-29 and SW-480) were inactivated with cisplatin (CDDP) and administrated as vaccines to the three groups of athymic C57BL/6 nude mice. Afterward, tumorigenesis was challenged with HT-29 cells. The antitumor effect of vaccines was evaluated by tumor and spleen examination and immune response analysis. The cytotoxic activity of splenocytes and serum levels of TGF-ß and IFN-γ were measured by Calcein-AM cytotoxicity assay and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS: The results of gene expression analysis showed that CCSCs are CD44+CD133-LGR5-. All vaccinations resulted in decreased tumor growth, spleen enlargement, enhanced serum level of IFN-γ and TGF-ß, and increased cytotoxic activity of natural killer (NK) cells. The antitumor efficacy of the CCSC vaccine was not more than CRC cell line-based vaccines. Interestingly, the allogeneic SW-480 vaccine could effectively inhibit tumorigenesis. CONCLUSION: Despite the great challenge in developing CCSC vaccines, allogeneic vaccines based on CRC cell lines can efficiently induce antitumor immunity in CRC.

In silico evidence of high frequency of miRNA-related SNPs in Esophageal Squamous Cell Carcinoma.

Esophageal squamous cell carcinoma (ESCC) is the dominant histological type of esophageal cancer significantly reported in developing nations. There is an increasing evidence suggesting that single nucleotide polymorphisms (SNPs) in the untranslated regions of genes (3'-UTRs) targeted by microRNAs (miRNAs) can change the target gene's expression and thereby affect the individual's cancer risk. Thus, in support of the role of SNPs occurring in miRNA target sites (miR-TS-SNPs) in the cancer, we analyzed the next generation sequencing data of 10 ESCC patients. In each patient, about 3,000 SNPs in 3'-UTRs were obtained in their whole-exome sequencing profiles. We applied two separate methods, manual and computational in silico approaches, to predict the miR-TS-SNPs with more effects on the miRNA-target interactions. dbSNP, 1000G, ExAC, Iranome, miRandb, miRCancer, TargetScan, Human, miRNASNP2 and miRBase databases were used for positive selection of miR-TS-SNPs and DIANA-miRPath v3.0 for pathway analysis. We identified six rare germline miR-TS-SNPs and two other ones with unknown miR-TS-SNPs. We interestingly observed all of these variants in only one patient, which can be evidence of the relationship between miR-TS-SNPs and cancer incidence. The study of cancer genetics including miR-TS-SNPs reveals miRNAs and their related pathways, which will be greatly useful in cancer research from noninvasive biomarkers to new treatments.

Potential cytotoxic and anti-metastatic effects of berberine on gynaecological cancers with drug-associated resistance.

Gynaecological disorders, such as cervical, ovarian, and endometrial cancers are the second most prevalent cancer types in women worldwide. Therapeutic approaches for gynaecological cancers involve chemotherapy, radiation, and surgery. However, lifespan is not improved, and novel medications are required. Among various phytochemicals, berberine, a well-known natural product, has been shown to be a promising cancer chemopreventive agent. Pharmacokinetics, safety, and efficacy of berberine have been investigated in the several experiments against numerous diseases. Here, we aimed to provide a literature review from available published investigations showing the anticancer effects of berberine and its various synthetic analogues against gynaecological disorders, including cervical, ovarian, and endometrial cancers. In conclusion, berberine has been found to efficiently inhibit viability, proliferation, and migration of cancer cells, mainly, via induction of apoptosis by both mitochondrial dependent and -independent pathways. Additionally, structural modification of berberine showed that berberine analogues can improve its antitumor effects against gynaecological cancers.

Morphine-Induced Analgesic Tolerance Effect on Gene Expression of the NMDA Receptor Subunit 1 in Rat Striatum and Prefrontal Cortex.

INTRODUCTION: Morphine is a potent analgesic but its continual use results in analgesic tolerance. Mechanisms of this tolerance remain to be clarified. However, changes in the functions of µ-opioid and N-Methyl-D-aspartate (NMDA) receptors have been proposed in morphine tolerance. We examined changes in gene expression of the NMDA receptor subunit 1 (NR1) at mRNA levels in rat striatum and prefrontal cortex (PFC) after induction of morphine tolerance. METHODS: Morphine (10 mg/kg, IP) was injected in male Wistar rats for 7 consecutive days (intervention group), but control rats received just normal saline (1 mL/kg, IP). We used a hotplate test of analgesia to assess induction of tolerance to analgesic effects of morphine on days 1 and 8 of injections. Later, two groups of rats were sacrificed one day after 7 days of injections, their whole brains removed, and the striatum and PFC immediately dissected. Then, the NR1 gene expression was examined with a semi-quantitative RT-PCR method. RESULTS: The results showed that long-term morphine a administration induces tolerance to analgesic effect of the opioid, as revealed by a significant decrease in morphine-induced analgesia on day 8 compared to day 1 of the injections (P<0.001). The results also showed that the NR1 gene expression at mRNA level in rats tolerant to morphine was significantly increased in the striatum (P<0.01) but decreased in the PFC (P<0.001). CONCLUSION: Therefore, changes in the NR1 gene expression in rat striatum and PFC have a region-specific association with morphine-induced analgesic tolerance.

Gene Expression Profile of Calcium/Calmodulin-Dependent Protein Kinase IIα in Rat's Hippocampus during Morphine Withdrawal.

INTRODUCTION: Calcium/calmodulin-dependent protein kinase II (CaMKII) which is highly expressed in the hippocampus is known to play a pivotal role in reward-related memories and morphine dependence. METHODS: In the present study, repeated morphine injections once daily for 7 days was done to induce morphine tolerance in male Wistar rats, after which gene expression profile of α-isoform of CaMKII (CaMKIIα) in the hippocampus was evaluated upon discontinuation of morphine injection over 21 days of morphine withdrawal. Control groups received saline for 7 consecutive days. For gene expression study, rats' brains were removed and the hippocampus was dissected in separate groups on days 1, 3, 7, 14, and 21 since discontinuation of of morphine injection. A semi-quantitative RT-PCR method was used to evaluate the gene expression profile. RESULTS: Tolerance to morphine was verified by a significant decrease in morphine analgesia in a hotplate test on day 8 (one day after the final repeated morphine injections). Results showed that gene expression of CaMKIIα at mRNA level on day 1, 3, 7, 14 and 21 of morphine withdrawal was significantly altered as compared to the saline control group. Post hoc Tukey's test revealed a significantly enhanced CaMKIIα gene expression on day 14. DISCUSSION: It can be concluded that CaMKIIα gene expression during repeated injections of morphine is increased and this increase continues up to 14 days of withdrawal then settles at a new set point. Therefore, the strong morphine reward-related memory in morphine abstinent animals may, at least partly be attributed to, the up-regulation of CaMKIIα in the hippocampus over 14 days of morphine withdrawal.

Blockades of ATP-sensitive potassium channels and L-type calcium channels improve analgesic effect of morphine in alloxan-induced diabetic mice.

In the present study interactions between analgesic effect of morphine with blockade of ATP-sensitive potassium channels and L-type calcium channels were investigated in alloxan-induced diabetic mice. A hot plate test was used to assess analgesic effect of drugs in adult male NMRI mice. All drugs were injected through an intraperitoneal route. A diabetic mouse model was established by injections of alloxan for three consecutive days. Seventy-two hours after the final injection, mice with a blood glucose level higher than 11.1mmol/l were considered as diabetic. The results showed that morphine at doses of 10 and 15mg/kg induced analgesia in both non-diabetic and diabetic mice, but the analgesic effect of morphine at dose of 7.5mg/kg was decreased in diabetic mice. Injections of an ATP-sensitive potassium channel blocker, glibenclamide (4, 8, 12, 20mg/kg) had no effect in non-diabetic mice, while at doses of 12 and 20mg/kg induced analgesia in diabetic mice. Blockade of L-type calcium channels with nimodipine at different doses (2.5, 5, 10 and 20mg/kg) was ineffective in non-diabetic mice, but at dose of 20mg/kg induced analgesia in diabetic mice. Co-administrations of glibenclamide (20mg/kg) or nimodipine (20mg/kg) along with different doses of morphine (5, 7.5 and 10mg/kg) improved the analgesic effect of the later drug in diabetic mice. According to the present results, it is possible that diabetes via affecting the potassium and calcium channels in the pain pathways may alter processing of pain in the peripheral and central nervous system.