[Study on the significance of intravoxel incoherent motion quantitative index combined with time-signal intensity curve in the early diagnosis of residual lesions in non-small cell lung cancer after argon-helium cryosurgery].

Objective: To study the application of intravoxel incoherent motion (IVIM) quantitative index combined with time-signal intensity curve (TIC) of dynamic contrast enhanced 3.0T magnetic resonance in the early precise diagnosis of residual lesions in non-small cell lung cancer (NSCLC) after argon-helium cryosurgery. Methods: One hundred NSCLC patients who underwent argon-helium cryosurgery were collected and divided into the residual group (21 cases) and non-residual group (79 cases) according to the result of needle biopsy and follow-up. The apparent diffusion coefficient (ADC), slow apparent diffusion coefficient (sADC), fast apparent diffusion coefficient (fADC), fraction of fast apparent diffusion coefficient (ffADC) and TIC type of IVIM quantitative index between the two groups were compared at 7 days and 1 month after argon-helium cryosurgery, respectively. The diagnosis performance of each quantitative index was analyzed by receiver operating characteristic (ROC) curve and the best cut-off value was computed. The specificity and sensitivity of TIC types were calculated as diagnostic criteria. The diagnosis performance of IVIM quantitative index combined with TIC type was evaluated and compared with the conventional MRI and DWI. Results: The differences of ADC, sADC and ffADC at 7 days and 1 month after argon-helium cryosurgery between the residual group and non-residual group were statistically significant (all P<0.05), in which the diagnosis performance of sADC and ffADC were better. The AUC of sADC and ffADC at 7 days after argon-helium cryosurgery were 0.861 and 0.895, the sensitivity were 81.0% and 90.5%, and the specificity were 77.2% and 73.4%, respectively. The AUC of sADC and ffADC at 1 month after argon-helium cryosurgery were 0.836 and 0.883, the sensitivity were 100.0% and 76.2%, and the specificity were 58.2% and 89.9%, respectively. The diagnosis performance of TIC type Ⅱ&Ⅲ was best. The sensitivity and specificity were 80.9% and 58.2% at 7 days after treatment, 85.7% and 62.0% at 1 month after treatment, respectively. At 7 days after treatment, the sensitivity and specificity of IVIM combined with TIC were 97.5% and 85.7%, while at 1 month after treatment, the sensitivity and specificity of IVIM combined with TIC were 97.5% and 90.5%, respectively. The diagnosis performance of IVIM quantitative index combined with TIC type was better than conventional MRI and DWI. Conclusion: The combination of IVIM quantitative index and TIC type can be used in the early diagnosis of residual lesions after argon-helium cryosurgery for NSCLC, whose effect is better than conventional MRI and DWI.

Cardiac over-expression of microRNA-1 induces impairment of cognition in mice.

Large cohort studies have revealed a close relationship between cognitive impairment and cardiovascular diseases, although the mechanism underlying this relationship remains incompletely understood. In this study, using a transgenic (Tg) mouse model of cardiac-specific over-expression of microRNA-1-2 (miR-1-2), we observed that microRNA-1 (miR-1) levels were increased not only in the heart but also in the hippocampus and blood, whereas its levels did not change in the skeletal muscle of Tg mice compared with age-matched wild-type (WT) mice. Six-month-old Tg mice showed cognitive impairment compared with age-matched WT mice, as assessed using the Morris Water Maze test. The brain-derived neurotrophic factor (BDNF) level and cyclic AMP-responsive element-binding protein (CREB) phosphorylation were also significantly reduced in the hippocampi of the Tg mice, as evaluated by Western blot. Further examination showed that BDNF protein expression was down- or up-regulated by miR-1 over-expression or inhibition, respectively, and was unchanged by binding site mutations or miRNA-masks for the 3'UTR of Bdnf, indicating that this gene is a potential target of miR-1. Knockdown of miR-1 by hippocampal stereotaxic injection of an anti-miR-1 oligonucleotide fragment carried by a lentivirus vector (lenti-pre-AMO-miR-1) led to up-regulation of BDNF expression and prevented the reduction in cognitive performance in the Tg mice without affecting cardiac function. Our findings demonstrate that cardiac over-expression of miR-1 also induces behavioral abnormalities that may be associated, at least in part, with the down-regulation of BDNF expression in the hippocampus. This study definitely contributes to the understanding of the relationship between cardiovascular disease and cognitive impairment.

Epigenetic mechanisms in chronic obstructive pulmonary disease.

Epigenetic modification may affect the expression of multiple inflammatory genes in lungs of patients with chronic obstructive pulmonary disease (COPD). Major epigenetic events include DNA methylation and various post-translational modifications of histones, such as histone methylation, acetylation, phosphorylation, ubiquitination, and sumoylation. Enzymes which regulate these epigenetic modifications can be activated by smoking. Both environmental and genetic factors play significant effect in development of COPD which have been reported by most references; however, little is known about the epigenetic pathways involved in the disease. Understanding the epigenetic mechanisms can help us clarify the pathogenesis of COPD and identify novel targets for developing new therapies for patients with COPD.

Harnessing the lysosome-dependent antitumor activity of phenothiazines in human small cell lung cancer.

Phenothiazines are a family of heterocyclic compounds whose clinical utility includes treatment of psychiatric disorders as well as chemotherapy-induced emesis. Various studies have demonstrated that these compounds possess cytotoxic activities in tumor cell lines of different origin. However, there is considerable confusion regarding the molecular basis of phenothiazine-induced cell death. Lung cancer (LC) remains one of the most prevalent and deadly malignancies worldwide despite considerable efforts in the development of treatment strategies, especially new targeted therapies. In this work, we evaluated the potential utility of phenothiazines in human LC. We show that phenothiazines as single treatment decreased cell viability and induced cell death preferentially in small cell lung carcinoma (SCLC) over non small cell lung carcinoma (NSCLC) cell lines. Sensitivity to phenothiazines was not correlated with induction of apoptosis but due to phenothiazine-induced lysosomal dysfunction. Interestingly, the higher susceptibility of SCLC cells to phenothiazine-induced cell death correlated with an intrinsically lower buffer capacity in response to disruption of lysosomal homeostasis. Importantly, this effect in SCLC occurred despite mutation in p53 and was not influenced by intrinsic sensitivity/resistance toward conventional chemotherapeutic agents. Our data thus uncovered a novel context-dependent activity of phenothiazines in SCLC and suggest that phenothiazines could be considered as a treatment regimen of this disease, however, extended cell line analyses as well as in vivo studies are needed to make such conclusion.

Resistance to DNA-damaging treatment in non-small cell lung cancer tumor-initiating cells involves reduced DNA-PK/ATM activation and diminished cell cycle arrest.

Increasing evidence suggests that tumor-initiating cells (TICs), also called cancer stem cells, are partly responsible for resistance to DNA-damaging treatment. Here we addressed if such a phenotype may contribute to radio- and cisplatin resistance in non-small cell lung cancer (NSCLC). We showed that four out of eight NSCLC cell lines (H125, A549, H1299 and H23) possess sphere-forming capacity when cultured in stem cell media and three of these display elevated levels of CD133. Indeed, sphere-forming NSCLC cells, hereafter called TICs, showed a reduced apoptotic response and increased survival after irradiation (IR), as compared with the corresponding bulk cell population. Decreased cytotoxicity and apoptotic signaling manifested by diminished poly (ADP-ribose) polymerase (PARP) cleavage and caspase 3 activity was also evident in TICs after cisplatin treatment. Neither radiation nor cisplatin resistance was due to quiescence as H125 TICs proliferated at a rate comparable to bulk cells. However, TICs displayed less pronounced G2 cell cycle arrest and S/G2-phase block after IR and cisplatin, respectively. Additionally, we confirmed a cisplatin-refractory phenotype of H125 TICs in vivo in a mouse xenograft model. We further examined TICs for altered expression or activation of DNA damage repair proteins as a way to explain their increased radio- and/or chemotherapy resistance. Indeed, we found that TICs exhibited increased basal γH2AX (H2A histone family, member X) expression and diminished DNA damage-induced phosphorylation of DNA-dependent protein kinase (DNA-PK), ataxia telangiectasia-mutated (ATM), Krüppel-associated protein 1 (KAP1) and monoubiquitination of Fanconi anemia, complementation group D2 (FANCD2). As a proof of principle, ATM inhibition in bulk cells increased their cisplatin resistance, as demonstrated by reduced PARP cleavage. In conclusion, we show that reduced apoptotic response, altered DNA repair signaling and cell cycle perturbations in NSCLC TICs are possible factors contributing to their therapy resistance, which may be exploited for DNA damage-sensitizing purposes.

miRNA-214 modulates radiotherapy response of non-small cell lung cancer cells through regulation of p38MAPK, apoptosis and senescence.

BACKGROUND: Radio- and chemotherapy (RT/CT) resistance hampers success in combating small and non-small cell lung cancers (SCLC/NSCLC). The underlying molecular mechanisms of RT/CT resistance of LCs are multifactorial and have been understood in part hitherto. miRNAs, key regulators of mRNAs, are well-recognised oncomirs; however, their role in regulating RT response remains poorly understood. METHODS: Six human NSCLC and five SCLC cell lines with different SF2 values were investigated. Using microarray we examined whether expression of miRNAs is linked to the RT resistance of NSCLCs or SCLCs. Obtained data were validated by quantitative real-time PCR. Apoptosis and senescence were analysed using siRNA transfection, western blot and flow cytometry. RESULTS: miRNA-21, miRNA-1827, miRNA-214, miRNA-339-5p, miRNA-625, miRNA-768-3p, miRNA-523-3p, miRNA-1227, miRNA-324-5p, miRNA-423-3p, miRNA-1301 and miRNA-1249 are differentially expressed in LC cells. miRNA-214 is upregulated in RT-resistant NSCLC cells relative to radiosensitive counterparts. Considering miRNA-214 as a putative regulator of RT resistance, we demonstrate that knockdown of miRNA-214 in radioresistant NSCLCs sensitised them to RT by stimulation of senescence. Consistently, overexpression of miRNA-214 in radiosensitive NSCLCs protected against RT-induced apoptosis. Protection was mediated by p38MAPK, as downregulation of this kinase could reverse the miRNA-214 overexpression-induced resistance of NSCLC cells. CONCLUSION: miRNA profiling of LC revealed putative RT resistance signalling circuits, which might help in sensitisation of LC to RT.

Chemosensitization by phenothiazines in human lung cancer cells: impaired resolution of γH2AX and increased oxidative stress elicit apoptosis associated with lysosomal expansion and intense vacuolation.

Chemotherapy resistance poses severe limitations on the efficacy of anti-cancer medications. Recently, the notion of using novel combinations of 'old' drugs for new indications has garnered significant interest. The potential of using phenothiazines as chemosensitizers has been suggested earlier but so far our understanding of their molecular targets remains scant. The current study was designed to better define phenothiazine-sensitive cellular processes in relation to chemosensitivity. We found that phenothiazines shared the ability to delay γH2AX resolution in DNA-damaged human lung cancer cells. Accordingly, cells co-treated with chemotherapy and phenothiazines underwent protracted cell-cycle arrest followed by checkpoint escape that led to abnormal mitoses, secondary arrest and/or a form of apoptosis associated with increased endogenous oxidative stress and intense vacuolation. We provide evidence implicating lysosomal dysfunction as a key component of cell death in phenothiazine co-treated cells, which also exhibited more typical hallmarks of apoptosis including the activation of both caspase-dependent and -independent pathways. Finally, we demonstrated that vacuolation in phenothiazine co-treated cells could be reduced by ROS scavengers or the vacuolar ATPase inhibitor bafilomycin, leading to increased cell viability. Our data highlight the potential benefit of using phenothiazines as chemosensitizers in tumors that acquire molecular alterations rendering them insensitive to caspase-mediated apoptosis.

Isolation of a spotted fever group rickettsia from a patient and related ecologic investigations in Xinjiang Uygur Autonomous Region of China.

Investigation of patients, healthy persons, and ticks in Jinghe County, Xinjiang Uygur Autonomous Region, People's Republic of China, for evidence of spotted fever group (SFG) rickettsiosis demonstrated strong evidence for a high prevalence of pathogenic SFG rickettsiae. Antibodies to SFG rickettsiae were detected in 62.5% of healthy subjects tested by enzyme-linked immunosorbent assay and 20% tested by complement fixation test. Two febrile patients were documented as having acute spotted fever rickettsiosis by complement fixation seroconversion. One, and 11-year-old Kazakh boy with eschar and regional lymphadenopathy, had an SFG rickettsia (An strain) isolated from his blood. A hemolymph test revealed that 20% of ticks contained rickettsiae. Two strains of SFG rickettsiae were isolated from male and female Dermacentor nuttalli ticks. The human SFG rickettsial isolate is the first to be obtained in the People's Republic of China.