Second report of TEDC1-related microcephaly caused by a novel biallelic mutation in an Iranian consanguineous family

BACKGROUND

Primary autosomal recessive microcephaly (MCPH) is a rare developmental disorder characterized by cognitive impairment, delayed neurodevelopment, and reduced brain size. It is a genetically heterogeneous condition, and several genes have been identified as associated with MCPH.

METHODS AND RESULTS

In this study, we utilized whole-exome sequencing (WES) to identify disease-causing variations in two brothers from an Iranian family affected by MCPH, who had consanguineous parents. In the patients, we detected a novel homozygous missense mutation (c.806A > G, p.Gln269Arg) in the TEDC1 gene in one of the patients. Co-segregation analysis using Sanger sequencing confirmed that this variant was inherited from parents. The identified variant was evaluated for its pathogenicity and novelty using various databases. Additionally, bioinformatics tools were employed to predict the three-dimensional structure of the mutant TEDC1 protein.

CONCLUSIONS

This study presents the second documented report of a mutation in the TEDC1 gene associated with MCPH. The identification of this novel biallelic mutation as a causative factor for MCPH in the proband further underscores the utility of genetic testing techniques, such as WES, as reliable diagnostic tools for individuals with this condition.

MicroRNAs and target molecules in bladder cancer

Bladder cancer (BC) is considered as one of the most common malignant tumors in humans with complex pathogenesis including gene expression variation, protein degradation, and changes in signaling pathways. Many studies on involved miRNAs in BC have demonstrated that they could be used as potential biomarkers in the prognosis, response to treatment, and screening before the cancerous phenotype onset. MicroRNAs (miRNAs) regulate many cellular processes through their different effects on special targets along with modifying signaling pathways, apoptosis, cell growth, and differentiation. The diverse expression of miRNAs in cancerous tissues could mediate procedures leading to the oncogenic or suppressor behavior of certain genes in cancer cells. Since a specific miRNA may have multiple targets, an mRNA could also be regulated by multiple miRNAs which further demonstrates the actual role of miRNAs in cancer. In addition, miRNAs can be utilized as biomarkers in some cancers that cannot be screened in the early stages. Hence, finding blood, urine, or tissue miRNA biomarkers by novel or routine gene expression method could be an essential step in the prognosis and control of cancer. In the present review, we have thoroughly evaluated the recent findings on different miRNAs in BC which can provide comprehensive information on better understanding the role of diverse miRNAs and better decision making regarding the new approaches in the diagnosis, prognosis, prevention, and treatment of BC.

Fractionated radiation promotes proliferation and radioresistance in bystander A549 cells but not in bystander HT29 cells

AIMS

Recent studies suggest that direct exposure of cells to fractionated radiotherapy might induce radioresistance. However, the effects of fractionated radiotherapy on the non-irradiated bystander cells remain unclear. We hypothesized that fractionated radiotherapy could enhance radioresistance and proliferation of bystander cells.

MAIN METHODS

Human tumor cell lines, including A549 and HT29 were irradiated (2 Gy per day). The irradiated cells (either A549 or HT29) were co-cultured with non-irradiated cells of the same line using transwell co-culture system. Tumor cell proliferation, radioresistance and apoptosis were measured using MTT assay, clonogenic survival assay and Annexin-V in bystander cells, respectively. In addition, activation of Chk1 (Ser 317), Chk2 (Thr 68) and Akt (Ser473) were measured via western blot.

KEY FINDINGS

Irradiated HT29 cells induced conventional bystander effects detected as modulation of clonogenic survival parameters (decreased area under curve, D₁₀ and ED₅₀ and increased α) and proliferation in recipient neighbors. While, irradiated A549 cells significantly enhanced the radioresistance and proliferation of bystander cells. These changes were accompanied with enhanced activation of Chk1, Chk2 and Akt in non-irradiated bystander A549 cells. Moreover, both bystander effects (damaging and protective) were mediated through secreted factors.

SIGNIFICANCE

These findings suggest that fractionated radiotherapy could promote proliferation and radioresistance of bystander cells probably through survival and proliferation pathways.

Relationship Study of The Verified H uman Epidermal Growth Factor Receptor 2 Amplification with Other Tumor Markers and Clinicohistopathological Characteristics in Patients with Invasive Breast Cancer, Using Chromogenic In Situ Hybridization

Objective

Human epidermal growth factor receptor 2 (HER-2), as a crucial factor involved in about 20% of breast cancer cases, is one of the most reliable tumor markers to determine prognosis and therapeutic trend of this disease. This marker is generally assessed by immunohistochemistry (IHC) technique. In the cases that result of IHC test cast doubt (+2), the test should be repeated or validated by applying in situ hybridization techniques, like chromogenic in situ hybridization (CISH). In this regard, the goal of current study was to figure out the link between different clinicopathological characteristics of patients suffering from invasive breast cancer, using tumor markers, hormone receptor (HR) and HER-2. Comparing IHC and CISH techniques for evaluating diagnostic value and usefulness of HER-2 were also the other objective of this study.

Materials and Methods

Based on this retrospective study, histological markers of 113 individuals suffering from invasive breast cancer -such as estrogen receptor (ER), progesterone receptor, HER-2 receptor, E-cadherin, CK5/6, vimentin and Ki67 were examined by IHC technique. HER-2 amplification of all patients was also evaluated by CISH. Clinicopathological information of the patients was also extracted from medical documents and their associations with tumor markers were statistically evaluated.

Results

There is a significant relationship between tumor size, CK5/6 and tumor grade with HR status. Similar relationship was observed between HER-2 status and HR status, as well as vascular invasion (P<0.05). The comparison of HER-2 amplification showed no complete concordance of the result obtained from these two techniques, with score +3.

Conclusion

Since the status of HER-2 is very important in decision making of the treatment process, CISH technique is recommended in the malignant conditions as the primary test, instead of IHC. In this study, we also determined that HER-2 expression is greatly correlated with ER- and PR- status. This might propose a better prognosis for HER-2⁺ patients.

New methods in the diagnosis of cancer and gene therapy of cancer based on nanoparticles

Cancer is one of the leading cause of death in the world with the prevalence of >10 million mortalities annually. Current cancer treatments include surgical intervention, radiation, and taking chemotherapeutic drugs, which often kill the healthy cells and result in toxicity in patients. Therefore, researchers are looking for ways to be able to eliminate just cancerous cells. Intra-tumor heterogeneity of cancerous cells is the main obstacle on the way of an effective cancer treatment. However, better comprehension of molecular basis of tumor and the advent of new diagnostic technologies can help to improve the treatment of various cancers. Therefore, study of epigenetic changes, gene expression of cancerous cells and employing methods that enable us to correct or minimize these changes is critically important. In this paper, we will review the recent advanced strategies being used in the field of cancer research.

Coinhibition of overexpressed genes in acute myeloid leukemia subtype M2 by gold nanoparticles functionalized with five antisense oligonucleotides and one anti-CD33(+)/CD34(+) aptamer

The aim of this study was to evaluate an engineered nanostructure to silence five important oncogenes, including BAG1, MDM2, Bcl-2, BIRC5 (survivin) and XIAP, in acute myeloid leukemia subtype 2 (AML-M2). The smart nanostructures were functionalized gold nanoparticles (FGNs) containing five antisense oligonucleotides (AOs) and one anti-CD33(+)/CD34(+) aptamer. First, the best AO for each gene was selected with the OligoWalk online software, and then different arrangements of AOs were evaluated with the RNAstructure software. Thereafter, naked gold nanoparticles (NGNs) were synthesized by the reaction of 1000 mm HAuCl4 with 10 μg ml(-1) ascorbic acid. Next, five AOs and one anti-CD33(+)/CD34(+) aptamer were attached to NGNs through serial reactions. Later, 5 ml of heparinized blood samples from five AML-M2 patients were prepared, cancerous cells were isolated and then incubated with three concentrations (75, 150 and 300 μg ml(-1)) each of FGNs, NGNs, gold nanoparticles functionalized with scrambled oligonucleotides (GNFSONs) and doxorubicin. Finally, cell death percentage and gene expressions were measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and real-time PCR, respectively. This study showed that FGNs and doxorubicin led to more cell death compared with NGNs and GNFSONs (P<0.05). Interestingly, all concentrations of FGNs led to a decrease in gene expression. As an important finding, although all concentrations of doxorubicin could also inhibit the expression of genes, FGNs had more effect (P<0.05). Moreover, both NGNs and GNFSONs could silence all genes only at a concentration of 300 μg ml(-1). For BCL2 and XIAP, a dose-dependent pattern was observed, but there was no similar pattern for others.