The association between sleep quantity, insomnia and lung cancer risk - A systematic review and meta-analysis.

PURPOSE: The effect of various sleep traits on the risk of lung cancer differs among pre-existing studies. This study aims to systematically review and synthesise the association between sleep duration and insomnia with the incidence of lung cancer. METHODS: PubMed, Embase and The Cochrane Library were searched from inception to 23 April 2023 for observational studies examining the effect of sleep quantity or insomnia on lung cancer incidence. We pooled maximally-adjusted hazard ratios and odds ratios separately using random effects inverse variance weighted models. The risk of bias of observational studies was assessed using the Newcastle-Ottawa Scale. RESULTS: We included 11 observational studies with a pooled cohort of 5,049,141 patients. The mean age of the patients was 49.5 ± 17.7 years, and 51.4% were males. The risk of bias ranged from low-moderate. Individuals who slept for a shorter or longer duration than the reference range of sleep per night showed an increased risk of lung cancer by 11% (HR:1.11; 95%CI:1.00-1.23) and 16% (HR:1.16; 95%CI:1.06-1.27) respectively. Furthermore, individuals with insomnia symptoms had a 9% greater risk of lung cancer than those without symptoms (HR:1.09; 95%CI:1.05-1.13). CONCLUSION: This study suggests that insufficient sleep, excessive sleep and insomnia may be associated with an increased risk of lung cancer. Physicians should be mindful of this association and encourage healthy sleep practises among patients. Given the observed heterogeneity among some pre-existing studies, future research with longer periods of follow-up, greater control for covariates and objective testing of sleep parameters may add value to this topic.

Autophagy inhibitors increase the susceptibility of KRAS-mutant human colorectal cancer cells to a combined treatment of 2-deoxy-D-glucose and lovastatin.

RAS-driven colorectal cancer relies on glucose metabolism to support uncontrolled growth. However, monotherapy with glycolysis inhibitors like 2-deoxy-D-glucose causes limited effectiveness. Recent studies suggest that anti-tumor effects of glycolysis inhibition could be improved by combination treatment with inhibitors of oxidative phosphorylation. In this study we investigated the effect of a combination of 2-deoxy-D-glucose with lovastatin (a known inhibitor of mevalonate pathway and oxidative phosphorylation) on growth of KRAS-mutant human colorectal cancer cell lines HCT116 and LoVo. A combination of lovastatin (>3.75 µM) and 2-deoxy-D-glucose (>1.25 mM) synergistically reduced cell viability, arrested cells in the G2/M phase, and induced apoptosis. The combined treatment also reduced cellular oxygen consumption and extracellular acidification rate, resulting in decreased production of ATP and lower steady-state ATP levels. Energy depletion markedly activated AMPK, inhibited mTOR and RAS signaling pathways, eventually inducing autophagy, the cellular pro-survival process under metabolic stress, whereas inhibition of autophagy by chloroquine (6.25 µM) enhanced the cytotoxic effect of the combination of lovastatin and 2-deoxy-D-glucose. These in vitro experiment results were reproduced in a nude mouse xenograft model of HCT116 cells. Our findings suggest that concurrently targeting glycolysis, oxidative phosphorylation, and autophagy may be a promising regimen for the management of RAS-driven colorectal cancers.

Symmetrical peripheral gangrene following brain surgery.

Symmetric peripheral gangrene is a rare but devastating complication, scarcely reported after brain surgery. We present a case of symmetric peripheral gangrene shortly after brain surgery of intracranial hematoma removal and aneurysm clipping.

Construction of an expression vector mediated by the dual promoter for prokaryotic and mammalian cell expression system.

The aim of this study was to construct an expression vector mediated by the dual promoter that can simultaneously drive the recombinant protein production in eukaryotic and prokaryotic cells. The prokaryotic T7 promoter and ribosome binding site (RBS) was cloned downstream of CMV promoter in the eukaryotic expression vector pIRES-neo, and T7 termination sequence was inserted upstream of neomycin phosphotransferase gene to generate the dual promoter vector. The enhanced green fluorescent protein (eGFP) gene was used as reporter gene. Then, the resultant vector was transfected into Chinese hamster ovary (CHO) cells and transformed into Escherichia coli (E. coli) BL21, and the eGFP expression levels were analyzed by fluorescence microscopy, flow cytometry and Western blot, respectively. Fluorescence microscopy revealed that the eGFP was expressed in both CHO cells and E. coli BL21. Flow cytometry showed that the eGFP expression level had no significant difference between the dual promoter vector and control vector in transfected CHO cells. Western blot analysis indicated the eGFP expressed in transformed E. coli. In conclusion, a prokaryotic-eukaryotic double expression vector was successfully constructed, which has potential applications in rapid cloning and expression of recombinant proteins in both prokaryotic and eukaryotic expression systems.

Distance effect characteristic of the matrix attachment region increases recombinant protein expression in Chinese hamster ovary cells.

OBJECTIVES: Previously, we have found that the matrix attachment region (MAR) may confer a 'distance effect' on transgene expression. This work aims to systematically explore the increased transgene expression in transfected Chinese hamster ovary (CHO) cells due to the characteristics of MAR and its mechanism. RESULTS: Compared with the control vector, 500 and 1000 bp DNA distances between MAR and the cytomegalovirus promoter can increase transgene expression by 1.77- and 1.56-fold, respectively. Meanwhile, transgene expression was not affected when 2000 and 2500 bp spacer DNAs were inserted, but a declining trend was observed when a 1500 bp spacer DNA was inserted. The vector containing a 500 bp DNA distance significantly increased the expression of the enhanced green fluorescent protein, and this increase was not related to transgene copy numbers. CONCLUSIONS: A short DNA distance-containing MAR confers high transgene expression level in transfected CHO cells, but a distance threshold does not exist in the vector system.

[Effects of Different Promoters and MAR Combinations on Transgene Expression of Recombinant CHO Cells].

OBJECTIVE: To analyze the effects of different promoters and matrix attachment region (MAR) on the expression of transgene in Chinese hamster ovary (CHO) cells. METHODS: The expression vector was constructed by the combination of beta globin MAR (gMAR) with the human cytomegalovirus immediate-early promoter (CMV-IE) and simian virus 40 (SV40) promoter. These vectors were transfected into CHO cells,after 48 h,the transient expression of enhanced green fluorescent protein (eGFP) was observed; G418 was used to screen stably transformed cell lines,and the expression level of eGFP in CHO cells was analyzed by flow cytometry. The relative copy numbers of eGFP were analyzed by qPCR. RESULTS: Without gMAR expression vector,the expression of eGFP which was driven by CMV-IE promoter was stronger than that of SV40 promoter; gMAR could increase the expression level of eGFP driven by CMV-IE promoter,but did not show any enhancement in SV40 promoter. The expression level of eGFP which containing gMAR on both sides was stronger than that of gMAR on one side driven by CMV-IE promoter; After G418 screening,the expression level of eGFP containing gMAR driven by SV40 promoter wasunstable,the fluorescence gradually weakened,therefore,we only analyzed the expression vector stably expressing the eGFP gene driven by CMV-IE promoter by flow cytometry and qPCR. Compared with the expression vector without gMAR containing CMV-IE promoter,flow cytometry showed that the expression levels of eGFP on one and both sides with gMAR were increased by 9.85-fold and 12.94-fold,respectivley; The result of qPCR showed that the copy number of the eGFP gene without gMAR was set to 1,the copy number of the eGFP gene in the expression vector driven by CMV-IE with gMAR on one side and both sides were 3.68-fold and 9.25-fold,respectively. CONCLUSION: The activity of CMV-IE promoter is stronger than that of SV40 promoter. gMAR can enhance the expression levels of transgene,which may be related to the increase of gene copy number.

Morphology and Optical Properties of RF Sputtering Deposited Indium Nitride Layers Under Different N2/Ar Ratio.

InN thin films were prepared using reactive radio frequency sputtering on (111) Si substrates under different N2/Ar ratio. The surface morphology and optical properties of InN thin films were characterized by X-ray diffraction, atomic force microscopy, scanning electron microscope, energy dispersive spectrometer, and UV-visible-NIR spectrophotometer at room temperature. It was found that the growth rate and surface RMS roughness of InN layers all significantly decreased with the increasing of N2 content in the sputtering gas. All the InN films were wurtzite structure with the proportion of N2 increasing from 40% to 100% in the mixture gas. The highly c-axis orientation InN films could only be obtained in the composition ratios of N2 higher than 90%. The atomic percentage of N is much higher than that of In at high N2 content films, which mainly due to the chemical reaction on the surface of Si substrate. The apparent optical band gap energy is estimated at 1.83 eV. However, the InN absorption band tail is strongly influenced by the sputtering due to a change in the species of the plasma.

Targeting miR-21 enhances the sensitivity of human colon cancer HT-29 cells to chemoradiotherapy in vitro.

5-Fluorouracil (5-FU) is a classic chemotherapeutic drug that has been widely used for colorectal cancer treatment, but colorectal cancer cells are often resistant to primary or acquired 5-FU therapy. Several studies have shown that miR-21 is significantly elevated in colorectal cancer. This suggests that this miRNA might play a role in this resistance. In this study, we investigated this possibility and the possible mechanism underlying this role. We showed that forced expression of miR-21 significantly inhibited apoptosis, enhanced cell proliferation, invasion, and colony formation ability, promoted G1/S cell cycle transition and increased the resistance of tumor cells to 5-FU and X radiation in HT-29 colon cancer cells. Furthermore, knockdown of miR-21 reversed these effects on HT-29 cells and increased the sensitivity of HT-29/5-FU to 5-FU chemotherapy. Finally, we showed that miR-21 targeted the human mutS homolog2 (hMSH2), and indirectly regulated the expression of thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD). These results demonstrate that miR-21 may play an important role in the 5-FU resistance of colon cancer cells.

Distance effect of matrix attachment regions on transgene expression in stably transfected Chinese hamster ovary cells.

The ß-globin matrix attachment regions (MARs) were inserted into the 5'-site of the eukaryotic expression vector cassette and DNA fragments 350 and 750 bp in length were inserted into the site to generate expression vectors with varying distances between the expression cassette and MAR. The vectors containing MARs increased chloramphenicol acetyltransferase (CAT) expression levels compared to the negative control vector lacking the MAR; the highest expression increase was 3.8-fold. A greater MAR-transgene distance (750 bp) correlated with a greater increase in transgene expression when compared to the control vector that lacked separation between the MAR and transgene. CAT gene copy numbers were higher in cells transformed with the vector possessing a smaller MAR-transgene distance (350 bp) than in cells belonging to the other three groups. However, MAR-induced transgene expression levels did not exhibit a direct relationship with gene copy number.

Olfactory Impairment and Frailty: A Systematic Review and Meta-Analysis.

Importance: Olfactory impairment (OI) and frailty are prevalent conditions associated with aging, but studies investigating their association with each other have been discordant. Objective: To summarize current evidence surrounding the association between OI and frailty. Data Sources: PubMed, Embase, Cochrane Library, SCOPUS, and CINAHL from inception to November 28, 2023. Study Selection: This study included observational studies investigating the association between objectively or subjectively assessed OI and objectively evaluated frailty among adults. Data Extraction and Synthesis: Two independent authors extracted data into a structured template. Maximally adjusted estimates were pooled using a random-effects model, and statistical heterogeneity was evaluated using I2 values. Additional prespecified subgroup and sensitivity analyses were performed. This study used the Newcastle-Ottawa Scale for bias assessment and the Grading of Recommendations Assessment, Development and Evaluation framework for overall evidence quality evaluation. Main Outcomes and Measures: The primary outcome was the cross-sectional association between OI and frailty, for which the odds of frailty were compared between participants with and without OI. The secondary outcome was the cross-sectional association between frailty and OI, for which the odds of OI were compared between participants with and without frailty. Results: This study included 10 studies with 10 624 patients (52.9% female; mean [SD] age, 62.9 [9.6] years). The Newcastle-Ottawa Scale score of studies ranged from low to moderate. Grading of Recommendations Assessment, Development and Evaluation scores ranged from low to moderate. OI was associated with a 2.32-fold (odds ratio [OR], 2.32; 95% CI, 1.63-3.31; I2 = 0%) greater odds of frailty compared with individuals with healthy olfactory function. The odds of OI was progressively greater with categorical frailty status, with a 1.55-fold (OR, 1.55; 95% CI, 1.32-1.82; I2 = 0%), 2.28-fold (OR, 2.28; 95% CI, 1.96-2.65; I2 = 0%), and 4.67-fold (OR, 4.67; 95% CI, 2.77-7.86; I2 = 0%) increase in odds for individuals with prefrailty, frailty, and the most frailty, respectively, compared with robust individuals. The results demonstrated stability in subgroup analyses (geographical continent of study, objective vs subjective olfactory assessment) and sensitivity tests. Conclusions and Relevance: The results of this systematic review and meta-analysis suggest that there is an association between OI and frailty, with an increase in the odds of OI with worsening categorical frailty status among individuals with prefrailty, frailty, and the most frailty. OI may be a potential biomarker for frailty. Future studies could delve into whether OI may be a modifiable risk factor for frailty.

Perceived stress and brain connectivity in subthreshold depression: Insights from eyes-closed and eyes-open states.

Perceived stress is an acknowledged risk factor for subthreshold depression (StD), and fluctuations in perceived stress are thought to disrupt the harmony of brain networks essential for emotional and cognitive functioning. This study aimed to elucidate the relationship between eye-open (EO) and eye-closed (EC) states, perceived stress, and StD. We recruited 27 individuals with StD and 33 healthy controls, collecting resting state fMRI data under both EC and EO conditions. We combined intrinsic connectivity and seed-based functional connectivity analyses to construct the functional network and explore differences between EC and EO conditions. Graph theory analysis revealed weakened connectivity strength in the right superior frontal gyrus (SFG) and right median cingulate and paracingulate gyrus (MCC) among participants with StD, suggesting an important role for these regions in the stress-related emotions dysregulation. Notably, altered SFG connectivity was observed to significantly relate to perceived stress levels in StD, and the SFG connection emerges as a neural mediator potentially influencing the relationship between perceived stress and StD. These findings highlight the role of SFG and MCC in perceived stress and suggest that understanding EC and EO states in relation to these regions is important in the neurobiological framework of StD. This may offer valuable perspectives for early prevention and intervention strategies in mental health disorders.

Effect of acupuncture and moxibustion on artery elasticity for early carotid atherosclerosis. / é’ˆç¸å¯¹é¢ˆåŠ¨è„‰ç²¥æ ·ç¡¬åŒ–æ—©æœŸæ‚£è€ è¡€ç®¡å¼¹æ€§çš„å½±å“.

OBJECTIVES: To observe the effect of acupuncture and moxibustion on arterial elasticity in patients with early carotid atherosclerosis. METHODS: A total of 62 patients with early carotid atherosclerosis were randomly divided into a blank group (12 cases, 1 cases dropped-off), a sham-acupuncture group (25 cases, 5 cases dropped-off) and an acupuncture group (25 cases, 3 cases dropped-off). Patients in the acupuncture group received acupuncture treatment, including ①acupuncture：Baihui (GV20), Yintang (GV24+), Renying (ST9), Neiguan (PC6), Yanglingquan (GB34)；②moxibustion：Yinqiguiyuan (Zhongwan ［CV12］, Xiawan ［CV10］, Qihai ［CV6］, Guanyuan ［CV4］), Sihua (Geshu ［BL17］, Danshu ［BL19］)；③Intradermal needle：Xinshu (BL15), Danshu (BL19). Patients in the sham acupuncture group received placebo acupuncture, moxibustion, an intradermal needle, and the acupoints were the same as the acupuncture group. The above treatments were performed twice a week for 12 weeks. No intervention was given to the patients in the blank group. Diet and lifestyle education was given to the three groups. The ultrafast pulse wave velocity, including beginning-systolic pulse wave velocity (BS) and end-systolic pulse wave velocity (ES), was observed before treatment and 1, 2, 3 months after treatment in the three groups. The blood lipid level and platelet count (PLT) at each time point were observed. The safety of the treatments was also evaluated. RESULTS: Compared with those before treatment, the BS and ES values of both sides in the acupuncture group decreased at 2 and 3 months after treatment (P<0.05). Compared with the blank group, the bilateral ES of the acupuncture group were decreased at 2 months after treatment (P<0.05), and the bilateral BS and ES were decreased at 3 months (P<0.05). Compared with the sham-acupuncture group, the acupuncture group showed a decrease in left BS and left ES after 3 months of treatment (P<0.05), and the overall decrease on the left side of the acupuncture group was better than that on the right side. There were no significant differences between three groups in the levels of blood lipid and PLT at each time point. No serious adverse safety events occurred in the three groups during the treatment. CONCLUSIONS: Acupuncture and moxibustion therapy can improve arterial elasticity in patients with early carotid atherosclerosis, and it is safe and effective.

Subregions of the fusiform gyrus are differentially involved in the attentional mechanism supporting visual mental imagery in depression.

BACKGROUND: Impaired visual mental imagery is an important symptom of depression and has gradually become an intervention target for cognitive behavioral therapy. METHODS: Our study involved a total of 25 healthy controls (HC) and 23 individuals with moderate depressive symptoms (MD). This study explored the attentional mechanism supporting visual mental imagery impairments in depression using the Vividness of Visual Imagery Questionnaire (VVIQ), attentional network test (ANT), and resting-state functional magnetic resonance imaging (rs-fMRI). The intrinsic activity of attention-related regions relative to those supporting visual mental imagery was identified in depression patients. In addition, a meta-analysis was used to describe the cognitive function related to this intrinsic activity. RESULTS: The global correlation (GCOR) of the right anterior fusiform gyrus (FG) was decreased in depression patients. Attention-related areas were concentrated in the right posterior FG; the anterior and posterior functional connectivity (FC) of the FG was decreased in depression patients. Graph theoretic analysis showed that the degree of the right anterior FG was decreased, the degree of the anterior insula was increased, and the negative connection between these two regions was strengthened in depression patients. In addition, the degree of the right anterior FG, the FC between the subregions of the right FG, and the FC between the right anterior FG and insula were correlated with VVIQ scores; however, this correlation was not significant in depression patients. The meta-analysis suggested that the changes in the anterior FG in depressed patients may stem from difficulties of semantic memory retrieval. CONCLUSION: The changed intrinsic activity of subregions of the FG relative to the semantic memory retrieval may be associated with visual mental imagery impairments in depression.

Notopterygium Incisum Extract Promotes Apoptosis by Preventing the Degradation of BIM in Colorectal Cancer.

OBJECTIVE: Colorectal cancer (CRC), a prevalent malignancy worldwide, has prompted extensive research into anticancer drugs. Traditional Chinese medicinal materials offer promising avenues for cancer management due to their diverse pharmacological activities. This study investigated the effects of Notopterygium incisum, a traditional Chinese medicine named Qianghuo (QH), on CRC cells and the underlying mechanism. METHODS: The sulforhodamine B assay and colony formation assay were employed to assess the effect of QH extract on the proliferation of CRC cell lines HCT116 and Caco-2. Propidium iodide (PI) staining was utilized to detect cell cycle progression, and PE Annexin V staining to detect apoptosis. Western blotting was conducted to examine the levels of apoptotic proteins, including B-cell lymphoma 2-interacting mediator of cell death (BIM), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (BAX) and cleaved caspase-3, as well as BIM stability after treatment with the protein synthesis inhibitor cycloheximide. The expression of BAX was suppressed using lentivirus-mediated shRNA to validate the involvement of the BIM/BAX axis in QH-induced apoptosis. The in vivo effects of QH extract on tumor growth were observed using a xenograft model. Lastly, APCMin+ mice were used to study the effects of QH extract on primary intestinal tumors. RESULTS: QH extract exhibited significant in vitro anti-CRC activities evidenced by the inhibition of cell proliferation, perturbation of cell cycle progression, and induction of apoptosis. Mechanistically, QH extract significantly increased the stability of BIM proteins, which undergo rapid degradation under unstressed conditions. Knockdown of BAX, the downstream effector of BIM, significantly rescued QH-induced apoptosis. Furthermore, the in vitro effect of QH extract was recapitulated in vivo. QH extract significantly inhibited the tumor growth of HCT116 xenografts in nude mice and decreased the number of intestinal polyps in the APCMin+ mice. CONCLUSION: QH extract promotes the apoptosis of CRC cells by preventing the degradation of BIM.

Species composition and diversity of parasitoids and hyper-parasitoids in different wheat agro-farming systems.

Insect communities depend on both their local environment and features of the surrounding habitats. Diverse plant communities may enhance the abundance and species diversity of local natural enemies, which is possible due to a higher abundance and species diversity in complex landscapes. This hypothesis was tested using cereal aphid parasitoids and hyper-parasitoids by comparing 18 spring wheat fields, Triticum aestivum L. (Poales: Poaceae), in structurally-complex landscapes (dominated by semi-natural habitat, > 50%, n = 9) and structurally-simple landscapes dominated by arable landscape (dominated by crop land, > 80%, n = 9). The agricultural landscape structure had significant effects on the number of parasitoid and hyper-parasitoid species, as 26 species (17 parasitoids and 9 hyper-parasitoids) were found in the complex landscapes and 21 were found in the simple landscapes (14 parasitoids and 7 hyper-parasitoids). Twenty-one species occurred in both landscape types, including 14 parasitoids and 7 hyper-parasitoids species. The species diversity of parasitoids and hyper-parasitoids were significantly different between the complex and simple landscapes. In addition, arable fields in structurally-simple agricultural landscapes with little semi-natural habitats could support a lower diversity of cereal aphid parasitoids and hyper-parasitoids than structurally-complex landscapes. These findings suggest that cereal aphid parasitoids and hyper-parasitoids need to find necessary resources in structurally-complex landscapes, and generalizations are made concerning the relationship between landscape composition and biodiversity in agricultural landscapes. Overall, abundance, species richness, and species diversity increased with increasing plant diversity and landscape complexity in spring wheat fields and increasing amounts of semi-natural habitats in the surrounding landscape.

Thresholds for triggering the propagation of meteorological drought to hydrological drought in water-limited regions of China.

Propagation thresholds that trigger a transition between meteorological drought and hydrological drought are poorly understood, which hinders effective establishment of drought warning systems and prevention measures. Here, propagation thresholds were assessed by firstly identifying drought events during 1961-2016 in the Yellow River Basin, China, subsequently pooling, excluding, and matching them, and finally assessing their threshold conditions by using a combined Copula function and transition rate (Tr) analysis. These results show that response time changed according to variations in drought duration and watershed characteristics. Importantly, response times increased according to the timescales over which they were studied; for example, the Wenjiachuan watershed recorded response times of 8, 10, 10, and 13 months when examined at 1-, 3-, 6-, and 12-month timescales, respectively. Additionally, the severity and duration of meteorological and hydrological drought events both increased when events were combined rather than studied individually. These effects were also amplified for matched meteorological and hydrological droughts by factors of 1.67 (severity) and 1.45 (duration), respectively. Shorter response times were identified in the Linjiacun (LJC) and Zhangjiashan (ZJS) watersheds, and correlated with their relatively small Tr values of 43 % and 47 %, respectively. Higher propagation thresholds for drought characteristics (e.g., 1.81 and 1.95 for drought severity in the LJC and ZJS watersheds, respectively) imply that shorter response times tended to have greater effects on hydrological drought events and lowered their Tr, and vice versa. These results provide new insight into propagation thresholds used for water resource planning and management, and may help to mitigate the effects of future climate change.

Berberine Decreases Thrombosis Potential Induced by a High-choline Diet by Inhibiting CutC Enzyme.

INTRODUCTION: Gut microbes influence thrombosis potential by generating trimethylamine N-oxide (TMAO). However, whether the antithrombotic effect of berberine is associated with TMAO generation remains unclear. OBJECTIVE: The present study was designed to explore whether berberine decreases the TMAO-induced thrombosis potential and the possible mechanism underneath it. METHODS: C57BL/6J female mice under a high-choline diet or standard diet were treated with/without berberine for 6 weeks. The TMAO level, carotid artery occlusion time following FeCl3 injury and platelet responsiveness were measured. The binding of berberine to the CutC enzyme was analysed with molecular docking, and molecular dynamics simulations were verified with enzyme activity assays. Results：The results showed that berberine increased the carotid artery occlusion time following FeCl3 injury and decreased the platelet hyperresponsiveness induced by a high-choline diet, both offset by intraperitoneal injection of TMAO. The effect of berberine on thrombosis potential was associated with decreasing the generation of TMAO by inhibiting the CutC enzyme. CONCLUSION: Targeting TMAO generation with berberine might be a promising therapy for ischaemic cardiac-cerebral vascular diseases.

Combination of MAR and intron increase transgene expression of episomal vectors in CHO cells.

Previous work has shown that the EF-1α promoter of episomal vectors maintains high-level transgene expression in stably transfected Chinese hamster ovary (CHO) cells. However, the transgene expression levels need to be further increased. Here, we first incorporated matrix attachment regions (MARs), ubiquitous chromatin opening element (UCOE), stabilizing anti repressor elements 40 (STAR 40) elements into episomal vector at different sites and orientations, and systemically assessed their effects on transgene expression in transfected CHO-K1 cells. Results showed that enhanced green fluorescent protein (eGFP) expression levels increased remarkably when MAR X-29 was inserted upstream of the promoter, followed by the insertion of MAR1 downstream of the poly A, and the orientation had no significant effect. Moreover, MAR X-29 combined with human cytomegalovirus intron (hCMVI) yielded the highest transgene expression levels (4.52-fold). Transgene expression levels were not exclusively dependent on transgene copy numbers and were not related to the mRNA expression level. In addition, vector with MAR X-29+hCMVI can induce herpes simplex virus thymidine kinase (HSV-TK) protein expression, and the HSV-TK protein showed a cell-killing effect and an obvious bystander effect on HCT116 cells. In conclusion, the combination of MAR X-29 and hCMV intron can achieve high efficiency transgene expression mediated by episomal vectors in CHO-K1 cells.

Knockdown of the SELENOK gene induces ferroptosis in cervical cancer cells.

Selenoprotein K (SELENOK) is one of the endoplasmic reticulum (ER) proteins that mainly functions in the regulation of ER stress, calcium flux, and antioxidant defense. Reactive oxygen species (ROS) is one of the key indicators of ferroptosis, and SELENOK inhibition could disrupt ROS balance, and consequently might cause ferroptosis. However, there are no previous studies about the mechanism of SELENOK in ferroptosis by regulating ROS. In this study, we report the effect of SELENOK inhibition on cell proliferation, viability, iron recycling-associated proteins, ROS, antioxidant enzymes, and lipid peroxidation of cervical cancer cells (HeLa cells). The results showed that ROS levels and iron-dependent lipid peroxidation were significantly enhanced, whereas cell viability and proliferation were significantly downregulated, and resulted in marked reductions in tumor size after SELENOK knockdown. SELENOK knockdown also caused steep decreases in glutathione peroxidase 4/glutathione levels and deterioration in ROS scavenging ability, and exacerbated ferroptosis in HeLa cells. Our findings elucidated that SELENOK knockdown could shrink tumor size by regulating ferroptosis, which might provide a theoretical basis for treating cervical cancer.