Efficacy of HMJ-38, a new quinazolinone analogue, against the gemcitabine-resistant MIA-PaCa-2 pancreatic cancer cells

Gemcitabine is frequently utilized to treat pancreatic cancer. The purpose of our study was to create a gemcitabine-resistant MIA-PaCa-2 pancreatic cancer cell line (MIA-GR100) and to evaluate the anti-pancreatic cancer efficacy of HMJ-38, a new quinazolinone analogue. Compared to their parental counterparts, MIA-PaCa-2, established MIA-GR100 cells were less sensitive to gemcitabine. MIA-GR100 cell viability was not affected by 10, 50 and 100 nM gemcitabine concentrations. HMJ-38 reduced MIA-GR100 cell growth and induced autophagy and apoptosis. When stained with monodansylcadaverine (MDC), acridine orange (AO), and terminal deoxynucleotide transferase dUTP nick end labeling (TUNEL), MIA-GR100 cells shrunk, punctured their membranes, and produced autophagy vacuoles and apoptotic bodies. Combining chloroquine (CQ) and 3-methyladenine (3-MA) with HMJ-38 dramatically reduced cell viability, indicating that autophagy function as a cytoprotective mechanism. MIA-GR100 cells treated with both z-VAD-FMK and HMJ-38 were much more viable than those treated with HMJ-38 alone. HMJ-38 promotes apoptosis in MIA-GR100 cells by activating caspases. Epidermal growth factor receptor (EGFR) is one of HMJ-38's principal targets, as determined via in silico target screening with network prediction. HMJ-38 also inhibited EGFR kinase activity and EGFR-associated signaling in MIA-GR100 cells. HMJ-38 may be an effective chemotherapeutic adjuvant for gemcitabine-resistant pancreatic cancer cells, in which it induces an antitumor response.

Hematopoietically expressed homeobox gene is associated with type 2 diabetes in KK Cg-Ay/J mice and a Taiwanese Han Chinese population

Diabetes mellitus (DM) is a chronic disease. The KK Cg-A^y/J (KK-A^y) mouse is an animal model to study type 2 diabetes mellitus (T2D) disease. The present study assessed the expression of hematopoietically expressed homeobox (HHEX) protein in liver tissues of different age groups of mice (6, 16 and 42 weeks) by immunohistochemistry (IHC). The results demonstrated a significant decrease in the percentage of HHEX-positive cells in KK-A^y mice as compared with that in KK-α/α control mice. Furthermore, in Taiwan's Han Chinese population, genotypic and allelic frequency distributions of the rs61862780 single-nucleotide polymorphism (SNP) in the HHEX gene were investigated. The results demonstrated that in the rs61862780 SNP of the 3′-untranslated region (UTR) of HHEX, the frequency of the CC genotype was higher in patients (6.0%) than in controls (2.7%), while the TT genotype frequency was about equal. In the same SNP, the frequency of the C allele was higher in patients (21.0%) than in controls (17.3%), while the T allele frequency was about equal. These results may pave the road for exploring the KK-A^y mouse model and the HHEX SNP rs61862780, which was correlated with the susceptibility to T2D in a Chinese population. Based on these findings, an association of HHEX gene expression with pathological features of T2D was indicated.

Pterostilbene modulates the suppression of multidrug resistance protein 1 and triggers autophagic and apoptotic mechanisms in cisplatin-resistant human oral cancer CAR cells via AKT signaling

Pterostilbene is a natural polyphenolic compound that is primarily found in fruits, such as blueberries and has a similar structure to resveratrol. Pterostilbene exhibits antioxidant, anti-inflammatory and antitumor activity but the effects of pterostilbene on drug-resistant oral cancer cells and its underlying mechanisms of action have not yet been explored. Therefore, the present study was performed to clarify the anticancer effects of pterostilbene on cisplatin-resistant human oral cancer CAR cells. The results demonstrated that CAR cells exhibited marked shrinkage, cell membrane breakage and autophagic vacuole formation following treatment with pterostilbene. Pterostilbene also effectively inhibited cell viability and suppressed cell confluence in a time- and concentration-dependent manner. Probing with acridine orange, monodansylcadaverine and LysoTracker Red demonstrated that the number of acidic vesicular organelles was increased, indicating increased autophagy. Furthermore, Heochst 33342 staining determined that DNA condensation, a characteristic of apoptosis, was enhanced following treatment with pterostilbene. Furthermore, pterostilbene upregulated mRNA levels of LC3-II and Atg12, as well as the expression of Atgs/Beclin-1/LC3-associated signaling, suggesting that it enhances autophagy. The autophagy inhibitors 3-methyladenine and chloroquine were used to confirm that pterostilbene induces autophagy. It was also determined that pterostilbene triggered caspase-dependent apoptosis by directly testing DNA breakage and using the pan-caspase inhibitor carbobenzoxyvalyl-alanyl-aspartyl fluoromethyl ketone. The results demonstrated that pterostilbene mediates the apoptosis of CAR cells via the intrinsic apoptotic cascade. In addition, pterostilbene inhibited MDR1 expression and the phosphorylation of AKT on the Ser473 site in CAR cells. Therefore, pterostilbene may elicit an oral anticancer response in drug-resistant cells and may be used as a chemotherapeutic adjuvant to treat patients with oral cancer.

Effect of bis(hydroxymethyl) alkanoate curcuminoid derivative MTH-3 on cell cycle arrest, apoptotic and autophagic pathway in triple-negative breast adenocarcinoma MDA-MB-231 cells: An in vitro study

Curcumin has been shown to exert potential antitumor activity in vitro and in vivo involved in multiple signaling pathways. However, the application of curcumin is still limited because of its poor hydrophilicity and low bio-availability. In the present study, we investigated the therapeutic effects of a novel and water soluble bis(hydroxymethyl) alkanoate curcuminoid derivative, MTH-3, on human breast adenocarcinoma MDA-MB-231 cells. This study investigated the effect of MTH-3 on cell viability, cell cycle and induction of autophagy and apoptosis in MDA-MB-231 cells. After 24-h treatment with MTH-3, a concentration-dependent decrease in MDA-MB-231 cell viability was observed, and the IC₅₀ value was 5.37±1.22 μM. MTH-3 significantly triggered G₂/M phase arrest and apoptosis in MDA-MB-231 cells. Within a 24-h treatment, MTH-3 decreased the CDK1 activity by decreasing CDK1 and cyclin B1 protein levels. MTH-3-induced apoptosis was further confirmed by morphological assessment and Annexin V/PI staining assay. Induction of apoptosis caused by MTH-3 was accompanied by an apparent increase of DR3, DR5 and FADD and, as well as a marked decrease of Bcl-2 and Bcl-xL protein expression. MTH-3 also decreased the protein levels of Ero1, PDI, PERK and calnexin, as well as increased the expression of IRE1α, CHOP and Bip that consequently led to ER stress and MDA-MB-231 cell apoptosis. In addition, MTH-3-treated cells were involved in the autophagic process and cleavage of LC3B was observed. MTH-3 enhanced the protein levels of LC3B, Atg5, Atg7, Atg12, p62 and Beclin-1 in MDA-MB-231 cells. Finally, DNA microarray was carried out to investigate the level changes of gene expression modulated by MTH-3 in MDA-MB-231 cells. Taken together, our results suggest that MTH-3 might be a novel therapeutic agent for the treatment of triple-negative breast cancer in the near future.

YC-1 induces G0/G1 phase arrest and mitochondria-dependent apoptosis in cisplatin-resistant human oral cancer CAR cells

Oral cancer is a serious and fatal disease. Cisplatin is the first line of chemotherapeutic agent for oral cancer therapy. However, the development of drug resistance and severe side effects cause tremendous problems clinically. In this study, we investigated the pharmacologic mechanisms of YC-1 on cisplatin-resistant human oral cancer cell line, CAR. Our results indicated that YC-1 induced a concentration-dependent and time-dependent decrease in viability of CAR cells analyzed by MTT assay. Real-time image analysis of CAR cells by IncuCyte™ Kinetic Live Cell Imaging System demonstrated that YC-1 inhibited cell proliferation and reduced cell confluence in a time-dependent manner. Results from flow cytometric analysis revealed that YC-1 promoted G₀/G₁ phase arrest and provoked apoptosis in CAR cells. The effects of cell cycle arrest by YC-1 were further supported by up-regulation of p21 and down-regulation of cyclin A, D, E and CDK2 protein levels. TUNEL staining showed that YC-1 caused DNA fragmentation, a late stage feature of apoptosis. In addition, YC-1 increased the activities of caspase-9 and caspase-3, disrupted the mitochondrial membrane potential (AYm) and stimulated ROS production in CAR cells. The protein levels of cytochrome c, Bax and Bak were elevated while Bcl-2 protein expression was attenuated in YC-1-treated CAR cells. In summary, YC-1 suppressed the viability of cisplatin-resistant CAR cells through inhibiting cell proliferation, arresting cell cycle at G₀/G₁ phase and triggering mitochondria-mediated apoptosis. Our results provide evidences to support the potentially therapeutic application of YC-1 on fighting against drug resistant oral cancer in the future.

Resveratrol-induced autophagy and apoptosis in cisplatin-resistant human oral cancer CAR cells: A key role of AMPK and Akt/mTOR signaling

Resveratrol is known to be an effective chemo-preventive phytochemical against multiple tumor cells. However, the increasing drug resistance avoids the cancer treatment in oral cavity cancer. In this study, we investigated the oral antitumor activity of resveratrol and its mechanism in cisplatin-resistant human oral cancer CAR cells. Our results demonstrated that resveratrol had an extremely low toxicity in normal oral cells and provoked autophagic cell death to form acidic vesicular organelles (AVOs) and autophagic vacuoles in CAR cells by acridine orange (AO) and monodansylcadaverine (MDC) staining. Either DNA fragmentation or DNA condensation occurred in resveratrol-triggered CAR cell apoptosis. These inhibitors of PI3K class III (3-MA) and AMP-activated protein kinase (AMPK) (compound c) suppressed the autophagic vesicle formation, LC3-II protein levels and autophagy induced by resveratrol. The pan-caspase inhibitor Z-VAD-FMK attenuated resveratrol-triggered cleaved caspase-9, cleaved caspase-3 and cell apoptosis. Resveratrol also enhanced phosphorylation of AMPK and regulated autophagy- and pro-apoptosis-related signals in resveratrol-treated CAR cells. Importantly, resveratrol also stimulated the autophagic mRNA gene expression, including Atg5, Atg12, Beclin-1 and LC3-II in CAR cells. Overall, our findings indicate that resveratrol is likely to induce autophagic and apoptotic death in drug-resistant oral cancer cells and might become a new approach for oral cancer treatment in the near future.

The Effectiveness of the Gene Which Slows the Rate of Wallerian Degeneration in C57BL/Ola Mice Declines With Age

The rate of Wallerian degeneration is unusually slow in severed axons of mice of the C57BL/Ola strain. Within mice of that strain we have now found that the rate of degeneration increases with the age of the animal. In 4-week-old mice nerve stimulation evokes muscle contractions even 5 days after sciatic nerve section and compound action potentials can be recorded in the distal nerve stump up to 3 weeks after section. In 1-year-old animals no action potentials can be excited 5 days after nerve section. Heterozygous mice carrying only one copy of the dominant gene show the same age-related decline in viability of the distal nerve stump after axotomy, and the rate of decline is no greater than for homozygous mice. The more rapid rate of degeneration of severed axons of mice of the C57BL/6J strain was affected in the opposite way by age, degeneration occurring more slowly in older animals.

Radial artery mycotic pseudoaneurysm: an unusual complication of catheterization

Radial artery pseudoaneurysms are rare, and those that become infected are rarer still. We present the case of a patient who developed a radial artery pseudoaneurysm as a late complication of arterial catheterization. Blood cultures were positive for Staphylococcus aureus, and a pulsatile mass, with associated tissue necrosis, was palpable over the radial artery. The diagnosis was confirmed by gray-scale and color Doppler sonography, which showed a partially thrombosed pseudoaneurysm and turbulent flow in the pseudoaneurysm and native artery.

Mycotic aneurysm presenting as Pancoast's syndrome in an injection drug user

Injection drug users frequently present to emergency departments with fever. A careful history and physical examination with attention to anatomic localization of symptoms and signs are often necessary to unmask unusual underlying medical conditions. We report a case of a woman with recent injection drug use who presented with fever, a palpable neck mass, and Pancoast's syndrome. She had been seen recently at the ED of another hospital and discharged with oral antibiotics for presumed cellulitis. A mycotic aneurysm of the subclavian artery causing Pancoast's syndrome was later diagnosed by using computed tomography and angiography. A high index of suspicion for anatomically localized infective processes should always be maintained with febrile injection drug users.

Altered brain metabolism in the C57BL/Wld mouse strain detected by magnetic resonance spectroscopy: association with delayed Wallerian degeneration?

In the C57BL/Wld(s) (Wld) mouse strain, both PNS and CNS axonal disintegration during Wallerian degeneration is dramatically slowed, with isolated axons being able to conduct compound action potentials (CAPs) for several weeks post-transection. The ability to conduct a CAP signifies the presence of an intact plasma membrane, normal ion gradients, and functioning ion channels. In neurons, ion homeostasis is primarily regulated by the Na(+)-K(+)-ATPase, which utilizes approximately 50% of neuronal energy output. To investigate the possibility that the Wld mutation prolongs axonal degeneration by conferring a more favorable energetic status to neurons or alters metabolism, we used 31P and 1H magnetic resonance spectroscopy (MRS) to compare the cerebral and muscle energy metabolism, membrane phospholipid contents, and water-soluble metabolites of Wld and wild-type (C57BL/6J [6J], and BALB/c) mouse strains. We first demonstrate that, with advancing age, transected Wld CNS nerves degenerate faster, paralleling previous findings in the PNS. We found significantly decreased phosphocreatine and phosphomonoester concentrations in the brains of Wld mice at 1- and 2-months of age compared to both 6J and BALB/c mice, but we failed to find differences in the adenylate (ATP, ADP, or AMP) or phospholipid concentrations. In another excitable tissue, skeletal muscle, no differences in energy-containing metabolites were detected. High resolution 1H MRS indicated that at 1 month of age, Wld brains have cytosolic levels of glutamate and phosphocholine that are significantly decreased, relative to total N-acetyl aspartate content. Our results demonstrate that delayed Wallerian degeneration in the C57BL/Wld mouse strain is associated with altered cerebral metabolism, although these changes may be secondary to the mutation.

Temperature modulation reveals three distinct stages of Wallerian degeneration

After peripheral nerve transection, axons distal to the cut site rapidly degenerate, a process termed Wallerian degeneration. In wild-type mice the compound action potential (CAP) disappears by 3 d. Previous studies have demonstrated that cold temperatures and lower extracellular calcium ion (Ca2+) concentrations can slow the rate of Wallerian degeneration. We have incubated isolated sciatic nerve segments from wild-type and C57BL/Wld mice (which carry a gene slowing Wallerian degeneration) in vitro at 25 and 37 degrees C. At 25 degrees C we found that the degeneration rate of wild-type axons was slowed dramatically, with the CAP preserved up to 7 d post-transection. In contrast, at 37 degrees C the CAPs were minimal at 2 d. When the temperature of wild-type nerves was raised to 37 degrees C after 24-72 hr at 25 degrees C, degeneration occurred within the subsequent 24 hr. Wld nerves, too, were preserved longer at 25 degrees C but, on return to 37 degrees C, degenerated promptly. Cooling the nerve within 12 hr after axotomy enhanced axonal preservation. Neither wild-type nor Wld nerves showed different degeneration rates when they were incubated with 250 microM or 5 or 10 mM extracellular Ca2+ for 1-2 d, suggesting that an abrupt increase in intracellular Ca2+ occurs at the time of axonal destruction. Wallerian degeneration, thus, appears to progress through three distinct stages. Initiation occurs at the time of injury with subsequent temperature-dependent and -independent phases. Nerves appear to remain intact and are able to exclude Ca2+ from entering until an as yet unknown process finally increases axolemmal permeability.

Persistence of neuromuscular junctions after axotomy in mice with slow Wallerian degeneration (C57BL/WldS)

The present study was undertaken to examine the fate of neuromuscular junctions in C57BL/WldS mice (formerly known as OLA mice) after nerve injury. When a peripheral nerve is injured, the distal axons normally degenerate within 1-3 days. For motor axons, an early event is deterioration of motor nerve terminals at neuromuscular junctions. Previously, the vulnerability of motor terminals has been attributed either to a 'signal' originating at the site of nerve injury and transported rapidly to the terminals or to their continual requirement for essential maintenance factors synthesized in the motor neuron cell body and supplied to the terminals by fast axonal transport. Mice of the WldS strain have normal axoplasmic transport but show an abnormally slow rate of axon and myelin degeneration. Structure and function are retained in the axons of distal nerve stumps for several days or even weeks after nerve injury in these mice. The results of the present study show that WldS neuromuscular junctions are also preserved and continue to release neurotransmitter and recycle synaptic vesicle membrane for at least 3 days and in some cases up to 2 weeks after nerve injury. Varying the site of the nerve lesion delayed degeneration by approximately 1-2 days per centimetre of distal nerve remaining. These findings suggest that the mechanisms of nerve terminal degeneration after injury are more complex than can be accounted for simply by the failure of motor neuron cell bodies to supply their terminals with essential maintenance factors. Rather, the data support the view that nerve section normally activates cellular components or processes already present, but latent, in motor nerve endings, and that in WldS mice either the trigger or the cellular response is abnormal.

Radiation-induced reductions in macrophage recruitment have only slight effects on myelin degeneration in sectioned peripheral nerves of mice

Macrophage recruitment into the distal nerve stump of the cut or crushed sciatic or saphenous nerves of C57BL/6J mice was reduced by prior whole body irradiation. This procedure was successful in keeping the numbers of cells stained with the mouse macrophage-specific antibody F4/80 to the levels found in unsectioned nerves. Quantitative image analysis of immunostained sections showed that the rate of loss of myelin basic protein was identical in nerves from irradiated and unirradiated mice up to 5 days but thereafter was slower in macrophage-deprived nerves. Similar analysis of semithin sections stained with toluidine blue detected more undegenerated myelin in the nerves from irradiated mice 10 days after operation. Quantitative counts made from electron micrographs of the sectioned nerves at 7 days also showed slightly less extensive myelin breakdown in the nerves from irradiated mice. Complete removal of myelin from some Schwann cells can occur without macrophages, but macrophages accelerate the removal of myelin in the later stages of Wallerian degeneration. It is concluded that there are two phases to the breakdown of myelin in peripheral nerves undergoing Wallerian degeneration: an initial stage entirely dependent on the activity of Schwann cells and a later stage dependent on both Schwann cells and the presence of macrophages.

Loss of the compound action potential: an electrophysiological, biochemical and morphological study of early events in axonal degeneration in the C57BL/Ola mouse

In the C57BL/Ola (Ola) mouse strain there is a marked slowing of axonal disintegration during Wallerian degeneration. The locus of the mutation controlling this phenomenon (slow Wallerian degeneration--Wlds) has been mapped to chromosome 4, and its protective effect decreases with advancing age. Using biochemical, electrophysiological and histological techniques, the present study was undertaken to determine whether neurofilament phosphorylation and stability are altered or whether calcium-activated proteases are absent in the sciatic nerves of Ola mice. A compound action potential was detectable only when neurofilaments were present and normal axonal architecture was seen. In 1-month-old Ola mice, compound action potentials and neurofilaments were still detectable at 21 days post-transection, whereas both were undetectable by 2 days in BALB/c and C57BL/6J (6J) mice of the same age. Neurofilament levels declined faster with advancing Ola age, confirming previous results, whereas degeneration slowed in ageing BALB/c and 6J mice. In vitro and in vivo degeneration rates were comparable in BALB/c and 6J nerves. Ola nerves, however, showed more rapid decline in vitro than in vivo. Ola and BALB/c nerves frozen and then thawed and incubated in the presence of calcium ions and the ionophore A23187 were not resistant to degradation by intrinsic proteases. Even when a compound action potential could no longer be elicited, however, a majority of nerves still had > 50% of myelinated and unmyelinated axons whose electron microscopic profiles appeared normal. Thus, it appears that the first event in Wallerian degeneration in the Ola mouse is a change at the plasma membrane--a transected nerve becomes unable to conduct a compound action potential.(ABSTRACT TRUNCATED AT 250 WORDS)

Retardation of calcification of bovine pericardium used in bioprosthetic heart valves by phosphocitrate and a synthetic analogue

The purpose of this study was to determine if phosphocitrate (PC), a naturally occurring inhibitor of calcification, and its synthetic analogue, N-sulpho-2-amino tricarballylate (SAT), administered either by daily injection or local delivery via Alzet osmotic minipump, could inhibit calcification of glutaraldehyde-preserved bovine pericardium used in bioprosthetic heart valves, subcutaneously implanted in rats. Local drug delivery, but not systemic administration, was effective. PC, administered by Alzet minipump (12 mg.kg-1.day-1), inhibited calcification significantly (tissue calcium = 5 +/- 2 micrograms/mg dry tissue, mean +/- SEM), compared with untreated or saline-treated controls (89 +/- 9 and 49 +/- 9 micrograms/mg, respectively). SAT, administered by the same route at both the same and a higher molar dosage, was less potent (tissue calcium = 26 +/- 9 micrograms/mg and 17 +/- 5 micrograms/mg, respectively). PC and SAT therapy were not associated with adverse effects. We conclude that locally administered PC and SAT can inhibit intrinsic calcification of bovine pericardium, with PC being more potent.