Triple-negative breast cancer (TNBC) is unresponsive to antiestrogen and anti-HER2 therapies, requiring the
use of cytotoxic drug combinations of anthracyclines, taxanes, cyclophosphamide, and platinum compounds.
Multidrug therapies achieve pathological cure rates of only 20–40%, a consequence of drug resistance and
cumulative dose limitations necessitated by the reversible cardiotoxic effects of drug therapy. Safer and more
effective treatments for TNBC are required to achieve durable therapeutic responses. This study describes the
mechanistic analyses of the novel anthracycline, pivarubicin, and its in vivo efficacy against human primary
TNBC. Pivarubicin directly activates PKCd, triggers rapid mitochondrial-dependent apoptosis, and circumvents resistance conferred by overexpression of P-glycoprotein, Bcl-2, Bcl-XL, and Bcr-Abl. As a consequence,
pivarubicin is more cytotoxic than doxorubicin against MDA-MB-231, and SUM159 TNBC cell lines grown
in both monolayer culture and tumorspheres. Comparative in vivo efficacy of pivarubicin and doxorubicin was
performed in an orthotopic NSG mouse model implanted with MDA-MB-231 human TNBC cells and treated
with the maximum tolerated doses (MTDs) of pivarubicin and doxorubicin. Tumor growth was monitored by
digital caliper measurements and determination of endpoint tumor weight and volume. Endpoint cardiotoxicity
was assessed histologically by identifying microvacuolization in ventricular cardiomyocytes. Primary tumors
treated with multiple rounds of doxorubicin at MTD failed to inhibit tumor growth compared with vehicletreated tumors. However, administration of a single MTD of pivarubicin produced significant inhibition of
tumor growth and tumor regression relative to tumor volume prior to initiation of treatment. Histological
analysis of hearts excised from drug- and vehicle-treated mice revealed that pivarubicin produced no evidence
of myocardial damage at a therapeutic dose. These results support the development of pivarubicin as a safer and
more effective replacement for doxorubicin against TNBC as well as other malignancies for which doxorubicin
therapy is indicated. 相似文献
Objectives: Coenzyme Q10 (CoQ10, ubiquinone) stands among the safest supplements in the elderly to protect against cardiovascular disorders. Noteworthy, CoQ10 deficiency is common in many surviving stroke patients as they are mostly prescribed statins for the secondary prevention of stroke incidence lifelong. Accordingly, the current study aims to experimentally examine whether CoQ10 supplementation in animals receiving atorvastatin may affect acute stroke-induced injury.
Methods: Adult rats underwent transient middle cerebral artery occlusion after atorvastatin pretreatment (5 or 10 mg/ kg/day; po; 30 days) with or without CoQ10 (200 mg/kg/day). After 24 hours ischemic/reperfusion injury, animals were subjected to functional assessments followed by cerebral molecular and histological to detect inflammation, apoptosis and oxidative stress.
Results: Animals dosed with 10 mg/kg presented the worst neurological function and brain damage in the acute phase of stroke injury. CoQ10 supplementation efficiently improved functional deficit and cerebral infarction in all stroke animals, particularly those exhibiting statin toxicity. Such benefits were associated with remarkable anti-inflammatory and anti-apoptotic effects, based on the analyzed tumor necrosis factor-α, interleukin-6, Bax/Bcl2 and cleaved caspase 3/9 immunoblots. Importantly, our fluoro-jade staining data indicated CoQ10 may revert the stroke-induced neurodegeneration. No parallel alteration was detected in stroke-induced oxidative stress as determined by malondialdehyde and 8-oxo-2′-deoxyguanosine levels.
Discussion: These data suggest that all stroke animals may benefit from CoQ10 administration through modulating inflammatory and degenerative pathways. This study provides empirical evidence for potential advantages of CoQ10 supplementation in atorvastatin-receiving patients which may not shadow its antioxidant properties. 相似文献
PRKAA1 (protein kinase AMP-activated catalytic subunit 1) is a catalytic subunit of AMP-activated protein
kinase (AMPK), which plays a key role in regulating cellular energy metabolism through phosphorylation,
and genetic variations in the PRKAA1 have been found to be associated with gastric cancer risk. However, the
effect and underlying molecular mechanism of PRKAA1 on gastric cancer tumorigenesis, especially the proliferation and apoptosis, are not fully understood. Our data showed that PRKAA1 is highly expressed in BGC-
823 and MKN45 cells and is expressed low in SGC-7901 and MGC-803 cells in comparison with the other
gastric cancer cells. PRKAA1 downregulation by shRNA or treatment of AMPK inhibitor compound C significantly inhibited proliferation as well as promoted cell cycle arrest and apoptosis of BGC-823 and MKN45 cells.
Moreover, the expression of PCNA and Bcl-2 and the activity of JNK1 and Akt signaling were also reduced
in BGC-823 and MKN45 cells after PRKAA1 downregulation. In vivo experiments demonstrated that tumor
growth in nude mice was significantly inhibited after PRKAA1 silencing. Importantly, inactivation of JNK1
or Akt signaling pathway significantly inhibited PRKAA1 overexpression-induced increased cell proliferation
and decreased cell apoptosis in MGC-803 cells. In conclusion, our findings suggest that PRKAA1 increases
proliferation and restrains apoptosis of gastric cancer cells through activating JNK1 and Akt pathways. 相似文献