Paclitaxel and docetaxel resistance in prostate cancer: Molecular mechanisms and possible therapeutic strategies.

Prostate cancer is among most malignant tumors around the world and this urological tumor can be developed as result of genomic mutations and their accumulation during progression towards advanced stage. Due to lack of specific symptoms in early stages of prostate cancer, most cancer patients are diagnosed in advanced stages that tumor cells display low response to chemotherapy. Furthermore, genomic mutations in prostate cancer enhance the aggressiveness of tumor cells. Docetaxel and paclitaxel are suggested as well-known compounds for chemotherapy of prostate tumor and they possess a similar function in cancer therapy that is based on inhibiting depolymerization of microtubules, impairing balance of microtubules and subsequent delay in cell cycle progression. The aim of current review is to highlight mechanisms of paclitaxel and docetaxel resistance in prostate cancer. When oncogenic factors such as CD133 display upregulation and PTEN as tumor-suppressor shows decrease in expression, malignancy of prostate tumor cells enhances and they can induce drug resistance. Furthermore, phytochemicals as anti-tumor compounds have been utilized in suppressing chemoresistance in prostate cancer. Naringenin and lovastatin are among the anti-tumor compounds that have been used for impairing progression of prostate tumor and enhancing drug sensitivity. Moreover, nanostructures such as polymeric micelles and nanobubbles have been utilized in delivery of anti-tumor compounds and decreasing risk of chemoresistance development. These subjects are highlighted in current review to provide new insight for reversing drug resistance in prostate cancer.

Prevalence of SARS-CoV-2 infection in neonates born to mothers or relatives with COVID-19.

BACKGROUND: In December 2019, in Wuhan, China, coronavirus disease 2019 (COVID-19) was emerged due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). It seems that children and neonates, similar to adult and elderly individuals, are at risk of SARS-CoV-2 infection. However, adequate data are not available about neonates infected with SARS-CoV-2. METHODS: This study evaluated the presence of SARS-CoV-2 infection in neonates born to mothers or relatives with COVID-19. This cross-sectional study was performed on 25,044 consecutive Iranian participants in Tehran, Iran, from January 2020 to August 2020. Viral ribonucleic acid (RNA) was extracted from 500 µl of the oropharyngeal and nasopharyngeal specimens of the participants. The genomic RNA of SARS-CoV-2 was detected by real-time polymerase chain reaction (PCR) assay. RESULTS: Out of all participants, 98 (0.40%) cases were neonates born to mothers or relatives with SARS-CoV-2 infection. Therefore, the current study was performed on these neonates. Out of 98 studied neonates, 6 (6.1%) cases had positive PCR results for SARS-CoV-2 infection. Moreover, among 98 studied neonates' mothers, 25 (25.5%) cases had positive PCR results for SARS-CoV-2 infection. CONCLUSION: The findings of this study demonstrated that the rate of COVID-19 in neonates born to mothers or relatives with SARS-CoV-2 infection in the Iranian population is about 6.1%.

High prevalence of occult hepatitis C virus infection in injection drug users with HIV infection.

One of the pathological forms of chronic hepatitis C is occult HCV infection (OCI), in which there is no detectable HCV RNA in plasma specimens but HCV RNA is present in PBMCs and liver biopsy specimens. The aim of this study is to estimate the prevalence of OCI in HIV-positive people who are injection drug users (IDUs). From April 2015 to August 2018, 161 Iranian IDUs with HIV infection enrolled in the study. Viral RNA was extracted from plasma and PBMC samples of participants, and the presence of HCV RNA was examined using RT nested PCR with primers from two conserved regions (5´-UTR and NS5B). HCV genotyping was performed using RFLP and sequencing methods. Of the 161 patients, 134 (83.2%) were positive for anti-HCV antibodies. All 27 patients who were negative for anti-HCV were also negative for HCV RNA in plasma, but five of them (18.5%) were positive for HCV RNA in PBMCs. Importantly, 9 out of 50 patients (18.0%) who apparently had recovered from HCV infection (i.e., were anti-HCV positive and HCV RNA negative) were positive for HCV RNA in PBMCs. Overall, 18.1% of the patients who had no signs of previous HCV infection or had apparently recovered from the disease had OCI. The HCV genotypes of the cases with OCI were as follows: five patients (35.7%) were infected with subtype 1a, eight patients (57.1%) were infected with subtype 3a, and one patient (7.1%) was infected with genotype 4. Thus, it seems that the prevalence of OCI in HIV-positive IDUs is extremely significant in Iran and is likely to delay the global eradication of HCV infection until 2030.

Molecular diagnosis of occult hepatitis C virus infection in Iranian injection drug users.

Occult HCV infection (OCI) has been described as the presence of hepatitis C virus (HCV) genomic RNA in hepatocytes and/or peripheral blood mononuclear cell (PBMC) specimens and the lack of HCV genomic RNA and anti-HCV antibodies (Abs) in plasma samples. Injection drug users (IDUs) are the most important high-risk group for infection with blood-borne viruses, particularly HCV. The purpose of this study was to determine the presence of OCI in IDUs. A prospective cross-sectional study of 126 consecutive Iranian IDUs was performed from March 2017 to January 2018. PBMCs were separated from blood samples from the participants, and after extraction of the viral RNA from the plasma and PBMC specimens, HCV RNA was detected in the samples using RT-nested PCR by amplification of the 5'-NTR of HCV. HCV genotyping was carried out using restriction a fragment length polymorphism (RFLP) assay. The viral RNA was amplified using RT-nested PCR with specific primers for the NS5B gene, and the PCR products were sequenced to confirm the results obtained by HCV RNA detection and HCV genotyping. Out of the 126 IDUs studied, 105 (83.3%) were negative for anti-HCV Abs and HCV RNA in plasma samples, whereas HCV RNA was detected in the PBMC samples of six (5.7%) participants, indicating that these individuals had OCI. Moreover, HCV genomic RNA was detected in PBMC samples from five (23.8%) of the 21 IDUs studied who were positive for anti-HCV Abs and negative for HCV genomic RNA in plasma specimens. These IDUs also had OCI. The HCV genotypes in the PBMC samples from the subjects with OCI were determined. Six (54.5%) subjects were infected with HCV subtype 3a, and five (45.5%) were infected with HCV subtype 1a. This study showed that 8.7% of the Iranian IDUs had OCI, and therefore, a study focusing on the diagnosis of OCI in these individuals can be valuable and informative.

Improved yeast delivery of fluconazole with a nanostructured lipid carrier system.

Despite the growing trends in the number of patients at risk for invasive fungal infections, management with current antifungal agents results in complications due to changes in the epidemiology and drug susceptibility of invasive fungal infections. In the present research fluconazole-loaded nanostructured lipid carriers were prepared using probe ultrasonication techniques and investigated the efficacy of the optimal formulation on a large number of Candida species. The morphology of the obtained nanostructured lipid carriers was characterized by transmission-electron microscopy. The minimum inhibitory concentrations (MIC) for the new formulations against strains of Candida were investigated using the Clinical and Laboratory Standards Institute document M27-A3 and M27-S4 as a guideline. The fluconazole-loaded nanostructured lipid carriers presented a spherical shape with a mean diameter, zeta potential and entrapment efficiency of 126.4±15.2nm, -35.1±3.0mV, and 93.6±3.5%, respectively. The drug release from fluconazole-loaded nanostructured lipid carriers exhibited burst-release behavior at the initial stage followed by sustained release over 24h. Using a new formulation of fluconazole led to a significant decrease in MICs for all Candida groups (P<0.05). Furthermore, C. albicans isolates showed more susceptibility to fluconazole-loaded nanostructured lipid carriers than C. glabrata and C. parapsilosis (P<0.05). The MIC50 drug concentration was obtained as 0.0625, 0.031 and 0.25µg/ml for fluconazole-resistant strains of C. albicans, C. glabrata, and C. parapsilosis, respectively. In conclusion, a novel delivery system which can be used as part of a strategy to improve the antifungal activity of fluconazole against various Candida strains with different susceptibilities to conventional formulations of fluconazole was evaluated.