Targeted Silencing of NRF2 by rituximab-conjugated nanoparticles increases the sensitivity of chronic lymphoblastic leukemia cells to Cyclophosphamide.

BACKGROUND: Targeting influential factors in resistance to chemotherapy is one way to increase the effectiveness of chemotherapeutics. The nuclear factor erythroid 2-related factor 2 (Nrf2) pathway overexpresses in chronic lymphocytic leukemia (CLL) cells and appears to have a significant part in their survival and chemotherapy resistance. Here we produced novel nanoparticles (NPs) specific for CD20-expressing CLL cells with simultaneous anti-Nrf2 and cytotoxic properties. METHODS: Chitosan lactate (CL) was used to produce the primary NPs which were then respectively loaded with rituximab (RTX), anti-Nrf2 Small interfering RNA (siRNAs) and Cyclophosphamide (CP) to prepare the final version of the NPs (NP-Nrf2_siRNA-CP). All interventions were done on both peripheral blood mononuclear cells (PBMCs) and bone marrow mononuclear cells (BMNCs). RESULTS: NP-Nrf2_siRNA-CP had satisfying physicochemical properties, showed controlled anti-Nrf2 siRNA/CP release, and were efficiently transfected into CLL primary cells (both PBMCs and BMNCs). NP-Nrf2_siRNA-CP were significantly capable of cell apoptosis induction and proliferation prevention marked by respectively decreased and increased anti-apoptotic and pro-apoptotic factors. Furthermore, use of anti-Nrf2 siRNA was corresponding to elevated sensitivity of CLL cells to CP. CONCLUSION: Our findings imply that the combination therapy of malignant CLL cells with RTX, CP and anti-Nrf2 siRNA is a novel and efficient therapeutic strategy that was capable of destroying malignant cells. Furthermore, the use of NPs as a multiple drug delivery method showed fulfilling properties; however, the need for further future studies is undeniable. Video Abstract.

Cell cycle involvement in cancer therapy; WEE1 kinase, a potential target as therapeutic strategy.

Mitosis is the process of cell division and is regulated by checkpoints in the cell cycle. G1-S, S, and G2-M are the three main checkpoints that prevent initiation of the next phase of the cell cycle phase until previous phase has completed. DNA damage leads to activation of the G2-M checkpoint, which can trigger a downstream DNA damage response (DDR) pathway to induce cell cycle arrest while the damage is repaired. If the DNA damage cannot be repaired, the replication stress response (RSR) pathway finally leads to cell death by apoptosis, in this case called mitotic catastrophe. Many cancer treatments (chemotherapy and radiotherapy) cause DNA damages based on SSBs (single strand breaks) or DSBs (double strand breaks), which cause cell death through mitotic catastrophe. However, damaged cells can activate WEE1 kinase (as a part of the DDR and RSR pathways), which prevents apoptosis and cell death by inducing cell cycle arrest at G2 phase. Therefore, inhibition of WEE1 kinase could sensitize cancer cells to chemotherapeutic drugs. This review focuses on the role of WEE1 kinase (as a biological macromolecule which has a molecular mass of 96 kDa) in the cell cycle, and its interactions with other regulatory pathways. In addition, we discuss the potential of WEE1 inhibition as a new therapeutic approach in the treatment of various cancers, such as melanoma, breast cancer, pancreatic cancer, cervical cancer, etc.

A novel mutation (4040-4045 nt. delA) in exon 14 of the factor VIII gene causing severe hemophilia A.

Hemophilia A is an X-linked congenital bleeding disorder caused by Factor VIII deficiency. Different mutations including point mutations, deletions, insertions and inversions have been reported in the FVIII gene, which cause hemophilia A. In the current study, with the use of conformational sensitive gel electrophoresis (CSGE) analysis, we report a novel 1-nt deletion in the A6 sequence at codons 1328-1330 (4040-4045 nt delA) occurring in exon 14 of the FVIII gene in a seven-year-old Iranian boy with severe hemophilia A. This mutation that causes frameshift and premature stop-codon at 1331 has not previously been reported in the F8 Hemophilia A Mutation, Structure, Test and Resource Site (HAMSTeRS) database.

Is the frameshift codons 8/9 (+G) [FSC 8/9 (+G)] beta-thalassemia mutation, detected by the polymerase chain reaction-amplification refractory mutation system, really FSC 8/9 (+G)?

There are several polymerase chain reaction (PCR)-based approaches for the analysis of known mutations. The PCR-amplification refractory mutation system (PCR-ARMS) is one of the best known and frequently used for the detection of beta-thalassemia (beta-thal) mutations. However, there is an important point to be considered when searching for the frameshift codon (FSC) 8 (-AA) and FSC 8/9 (+G) mutations. Whereas the primer is specific for the FSC 8 mutation only, the primer for the FSC 8/9 mutation does not discriminate between the FSC 8/9 and FSC 8 mutations. Thus, the high number of FSC8/9 mutations reported in countries like India, Pakistan and some regions of Iran may be due to the use of the FSC 8/9 primer, without taking the FSC 8 mutation into account. It is thus advisable to test for FSC 8 before the FSC 8/9 mutation whenever PCR-ARMS is the method of investigation for these two mutations.