- DNA Double Strand Breaks Repair Inhibitors: Relevance as Potential New Anticancer Therapeutics. [Journal Article]
- CMCurr Med Chem 2018 Feb 13
- DNA Double-strand breaks are considered one of the most lethal form of DNA damage. Many effective anticancer therapeutic approaches used chemical and physical methods to generate DNA double-strand br...
DNA Double-strand breaks are considered one of the most lethal form of DNA damage. Many effective anticancer therapeutic approaches used chemical and physical methods to generate DNA double-strand breaks in the cancer cells. They include: IR and drugs which mimetic its action, topoisomerase poisons, some alkylating agents or drugs which affected DNA replication process. On the other hand, cancer cells are mostly characterized by highly effective systems of DNA damage repair. There are two main DNA repair pathways used to fix double-strand breaks: NHEJ and HRR. Their activity leads to a decreased effect of chemotherapy. Targeting directly or indirectly the DNA double-strand breaks response by inhibitors seems to be an exciting option for anticancer therapy and is a part of novel trends that arise after the clinical success of PARP inhibitors. These trends will provide great opportunities for the development of DNA repair inhibitors as new potential anticancer drugs. The main objective of this article is to address these new promising advances.
- A High-risk Haplotype for Premature Menopause in Childhood Cancer Survivors Exposed to Gonadotoxic Therapy. [Journal Article]
- JNCIJ Natl Cancer Inst 2018 Feb 08
- CONCLUSIONS: The haplotype captures the majority of clinically diagnosed PM cases and, with further validation, may have clinical application in identifying the highest-risk survivors for PM for possible intervention by cryopreservation.
- DNA repair mechanisms in response to genotoxicity of warfare agent sulfur mustard. [Review]
- ETEnviron Toxicol Pharmacol 2018 Feb 02; 58:230-236
- Sulfur mustard (SM) is an alkylating agent that causes severe damages to the skin, eyes, and the respiratory system. DNA alkylation is one of the most critical lesions that could lead to monoadducts ...
Sulfur mustard (SM) is an alkylating agent that causes severe damages to the skin, eyes, and the respiratory system. DNA alkylation is one of the most critical lesions that could lead to monoadducts and cross-links, as well as DNA strand breaks. In response to these adducts, cells initiate a series of reactions to recruit specific DNA repair pathways. The main DNA repair pathways in human cells, which could be involved in the DNA SM-induced DNA damages, are base excision repair (BER), nucleotide excision repair (NER), homologous recombination (HR) and non-homologous end joining (NHEJ). There is, thus, a need for a short review to clarify which damage caused by SM is repaired by which repair pathway. Increasing our knowledge about different DNA repair mechanisms following SM exposure would lay the first step for developing new therapeutic agents to treat people exposed to SM. In this review, we describe the major DNA repair pathways, according to the DNA adducts that can be caused by SM.
- Temozolomide-perillyl alcohol conjugate downregulates O6-methylguanin DNA methltransferase via inducing ubiquitination-dependent proteolysis in non-small cell lung cancer. [Journal Article]
- CDCell Death Dis 2018 Feb 09; 9(2):202
- The DNA repair enzyme O6-methylguanin-DNA-methltransferase (MGMT) is able to remove products of alkylating agent such as O6-meG and emerges as a central determinant of cancer resistance to temozolomi...
The DNA repair enzyme O6-methylguanin-DNA-methltransferase (MGMT) is able to remove products of alkylating agent such as O6-meG and emerges as a central determinant of cancer resistance to temozolomide (TMZ). Temozolomide-perillyl alcohol conjugate (TMZ-POH), a novel TMZ analog developed based on the conjugation of TMZ and POH, displayed strong anticancer potency in multiple cancer types, but seemed not to experience the chemoresistance even in cells with high MGMT expression unlike TMZ and other alkylating agents. In this study, we demonstrated TMZ-POH inhibited MGMT dependent on proteasomal pathway and this inhibition is a significant factor in its toxic effect in the non-small cell lung cancer (NSCLC) cells.
- Mobilization of human mesenchymal stem cells through different cytokines and growth factors after their immobilization by sulfur mustard. [Journal Article]
- TLToxicol Lett 2018 Feb 06
- CONCLUSIONS: The effect of sulfur mustard on MSC might play an important role in the persistence of long-term adverse effects; here the reduced migration could particularly be important. The compensation of the SM-induced migration reduction by addition of cytokines could possibly solve this problem. Moreover, our current results will help to understand the relationship between alkylating agents and MSC and thus will also give guidance in the future perspective for the therapeutic use of MSC in patients suffering from sulfur mustard induced chronic skin wounds.
- Chemotherapeutic Agents and the Risk of Ischemia and Arterial Thrombosis. [Review]
- CACurr Atheroscler Rep 2018 Feb 08; 20(2):10
- Numerous chemotherapeutic agents have been associated with the development of ischemia and arterial thrombosis. As newer therapies have been developed to treat cancer, some of these chemotherapy drug...
Numerous chemotherapeutic agents have been associated with the development of ischemia and arterial thrombosis. As newer therapies have been developed to treat cancer, some of these chemotherapy drugs have been implicated in the development of vascular disease. In this review, we will summarize the most common chemotherapeutic drug classes that may play a role in the development of ischemic heart disease.
- Combination of a hypomethylating agent and inhibitors of PARP and HDAC traps PARP1 and DNMT1 to chromatin, acetylates DNA repair proteins, down-regulates NuRD and induces apoptosis in human leukemia and lymphoma cells. [Journal Article]
- OOncotarget 2018 Jan 09; 9(3):3908-3921
- Combination of drugs that target different aspects of aberrant cellular processes is an efficacious treatment for hematological malignancies. Hypomethylating agents (HMAs) and inhibitors of poly(ADP-...
Combination of drugs that target different aspects of aberrant cellular processes is an efficacious treatment for hematological malignancies. Hypomethylating agents (HMAs) and inhibitors of poly(ADP-ribose) polymerases (PARPis) and histone deacetylases (HDACis) are clinically active anti-tumor drugs. We hypothesized that their combination would be synergistically cytotoxic to leukemia and lymphoma cells. Exposure of AML and lymphoma cell lines to the combination of the PARPi niraparib (Npb), the HMA decitabine (DAC) and the HDACi romidepsin (Rom) or panobinostat (Pano) synergistically inhibited cell proliferation by up to 70% via activation of the ATM pathway, increased production of reactive oxygen species, decreased mitochondrial membrane potential, and activated apoptosis. Addition of the DNA alkylating agents busulfan (Bu) and/or melphalan enhanced the anti-proliferative/cytotoxic effects of the triple-drug combination. [Npb+DAC+Rom] significantly increased the level of chromatin-bound PARP1 and DNMT1 and caused acetylation of DNA repair proteins, including Ku70, Ku80, PARP1, DDB1, ERCC1 and XPF/ERCC4. This three-drug combination down-regulated the components of the nucleosome-remodeling deacetylase (NuRD) complex, which is involved in DNA-damage repair. Addition of Bu to this combination further enhanced these effects on NuRD. The trapping of PARP1 and DNMT1 to chromatin, acetylation of DNA repair proteins, and down-regulation of NuRD may all have increased double-strand DNA break (DSB) formation as suggested by activation of the DNA-damage response, concomitantly resulting in tumor cell death. Similar synergistic cytotoxicity was observed in blood mononuclear cells isolated from patients with AML and lymphoma. Our results provide a rationale for the development of [Npb+DAC+Rom/Pano] combination therapies for leukemia and lymphoma patients.
- Synchronous papillary thyroid cancer and non-Hodgkin lymphoma: Case report. [Case Reports]
- MMedicine (Baltimore) 2018; 97(6):e9831
- CONCLUSIONS: The synchronous DTC and NHL is rare. To date, there is no standardized approach due to lack of experience. We suggest lymphoma first approach with synchronized and tailored multidisciplinary efforts. The molecular mechanisms of this link are poorly understood and yet remain to be elucidated.
- [Acquisition of IgH/CCND1 translocation during the natural disease course in a patient with chronic lymphocytic leukemia]. [Journal Article]
- RKRinsho Ketsueki 2018; 59(1):51-57
- A 69-year-old man visited a doctor because of systemic lymphadenopathy. Peripheral blood examination revealed leukocytosis, anemia, and decreased platelet count (WBC, 103,060/µl; lymph, 92.2%; Hb, 8....
A 69-year-old man visited a doctor because of systemic lymphadenopathy. Peripheral blood examination revealed leukocytosis, anemia, and decreased platelet count (WBC, 103,060/µl; lymph, 92.2%; Hb, 8.9 g/dl; and Plt, 4.1×104/µl). Bone marrow biopsy revealed that approximately 70% of nucleated cells were small, mature lymphoid cells with positive immunostaining for CD5, CD20, and CD23. He was diagnosed with chronic lymphocytic leukemia (CLL). The IgH/CCND1 translocation and ATM locus loss in 20% and 95% peripheral cells, respectively, were detected by fluorescence in situ hybridization. Immunostaining revealed that cyclin D1 was positive in approximately 30% bone marrow cells. As the positive rate of CCND1 fusion signal was low, the diagnosis of mantle cell lymphoma was excluded. In contrast, signals of ATM locus deletion were detected in most tumor cells. Therefore, we assessed that IgH/CCND1 translocations occurred during the natural clinical course of CLL with ATM locus deletion from the onset of disease. The secondary IgH/CCND1 translocation in CLL is rare, and all reported cases with such translocations received treatments with alkylating agents. This is the first report regarding secondary IgH/CCND1 translocation during the natural clinical course of CLL and may provide insights into CLL pathogenesis.
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- Reactive oxygen species-responsive nanoprodrug with quinone methides-mediated GSH depletion for improved chlorambucil breast cancers therapy. [Journal Article]
- JCJ Control Release 2018 Feb 02; 274:56-68
- Prodrug-based stimuli-responsive vectors have emerged as highly promising platform. Inspired by the fact that antioxidant systems including glutathione (GSH) make cancer cells adapt to oxidative stre...
Prodrug-based stimuli-responsive vectors have emerged as highly promising platform. Inspired by the fact that antioxidant systems including glutathione (GSH) make cancer cells adapt to oxidative stress and play a role in the inactivation of alkylating agents like chlorambucil (CHL) inside tumor cells, while arylboronic acid could transform into GSH depleting agent quinone methide (QM) upon degradation by reactive oxygen species (ROS) over-expressed in tumor cells, a ROS-responsive nanoprodrug (denoted by PPAHC) of CHL was established by integrating CHL into diols-containing hydrophilic polymer with self-immolative linker 4-(hydroxymethyl)phenylboronic acid (HPBA). The prodrug could form core-shell nanoparticle and possess high stability during storage. Drug release profile of PPAHC nanoprodrug demonstrated that nature CHL could be quickly released from PPAHC nanoprodrug in the presence of hydrogen peroxide (H2O2). Moreover, PPAHC nanoprodrug showed improved therapeutic efficiency compared to CHL via anti-proliferative study and cell apoptosis assay. Further measurement of GSH content and ROS levels in tumor cells suggested that the synergistic impact resulted from QM-mediated GSH reduction and CHL-induced further oxidative stress insults to tumor cells. In vivo tumor suppression effect and biocompatibility indicated the superiorities of PPAHC nanoprodrug. Accordingly, PPAHC provides a new approach as a ROS-responsive CHL delivery system and has a great potential for cancer therapy.