Pan-cancer analysis of chromothripsis-related gene expression patterns indicates an association with tumor immune and therapeutic agent responses.

Chromothripsis is a catastrophic event involving numerous chromosomal rearrangements in confined genomic regions of one or a few chromosomes, causing complex effects on cells via the extensive structural variation. The development of whole-genome sequencing (WGS) has promoted great progress in exploring the mechanism and effect of chromothripsis. However, the gene expression characteristics of tumors undergone chromothripsis have not been well characterized. In this study, we found that the transcriptional profile of five tumor types experiencing chromothripsis is associated with an immune evasion phenotype. A gene set variation analysis (GSVA) was used to develop a CHP score, which is based on differentially expressed gene sets in the TCGA database, revealing that chromothripsis status in multiple cancers is consistent with an abnormal tumor immune microenvironment and immune cell cytotoxicity. Evaluation using four immunotherapy datasets uncovered the ability of the CHP score to predict immunotherapy response in diverse tumor types. In addition, the CHP score was found to be related to resistance against a variety of anti-tumor drugs, including anti-angiogenesis inhibitors and platinum genotoxins, while EGFR pathway inhibitors were found to possibly be sensitizers for high CHP score tumors. Univariate COX regression analysis indicated that the CHP score can be prognostic for several types of tumors. Our study has defined gene expression characteristics of tumors with chromothripsis, supporting the controversial link between chromothripsis and tumor immunity. We also describe the potential value of the CHP score in predicting the efficacy of immunotherapy and other treatments, elevating chromothripsis as a tool in clinical practice.

A subset of VEGFR-TKIs activates AMPK in LKB1-mutant lung cancer.

The mutation of tumor suppressor gene liver kinase B1 (LKB1) has a prevalence of about 20% in non-small cell lung cancer (NSCLC). LKB1-mutant lung cancer is characterized by enhanced aggressiveness and immune escape and is associated with poor prognosis. Therefore, it is urgent to develop effective therapeutic methods for LKB1-mutant NSCLC. Recently, apatinib, a VEGFR-TKI, was found to significantly improve the outcome of LKB1-mutant NSCLC, but the mechanism is not completely clear. In this study, AMP-activated protein kinase (AMPK), the crucial downstream kinase of LKB1 was excavated as the potential target of apatinib. Biochemical experiments verified that apatinib is a direct AMPK activator. Moreover, clinically available VEGFR-TKIs were found to regulate AMPK differently: Apatinib and anlotinib can directly activate AMPK, while axitinib and sunitinib can directly inhibit AMPK. Activation of AMPK by apatinib leads to the phosphorylation of acetyl-CoA carboxylase (ACC) and inhibition of de novo fatty acid synthesis (FAsyn), which is upregulated in LKB1-null cancers. Moreover, the killing effect of apatinib was obviously enhanced under delipidated condition, and the combination of exogenous FA restriction with apatinib treatment can be a promising method for treating LKB1-mutant NSCLC. This study discovered AMPK as an important off-target of apatinib and elucidated different effects of this cluster of VEGFR-TKIs on AMPK. This finding can be the basis for the accurate and combined application of these drugs in clinic and highlights that the subset of VEGFR-TKIs including apatinib and anlotinib are potentially valuable in the treatment of LKB1-mutant NSCLC.

Impact of preoperative transcatheter rectal arterial chemoembolization with concurrent chemoradiotherapy on surgery and prognosis of patients with locally advanced rectal cancer.

BACKGROUND AND OBJECTIVES: To analyze and evaluate the impact of preoperative transcatheter rectal arterial chemoembolization (TRACE) with concurrent chemoradiotherapy on surgery and prognosis of locally advanced rectal cancer (LARC). METHODS: A total of 118 patients with LARC were enrolled in this nonrandomized prospective study. They were assigned into the experimental group receiving preoperative TRACE with concurrent chemoradiotherapy (TRACE-CRT group, N = 60) and the control group receiving only neoadjuvant chemoradiotherapy (CRT group, N = 58). All patients underwent surgery after their preoperative treatments. RESULTS: All patients successfully completed the surgical operation. No significant differences were found in sphincter preservation rate and R0 resection rate between TRACE-CRT group and CRT group (p > 0.05). No significant differences were found between the two groups in terms of the perioperative indicators and postoperative complications except mean operation time (165.8 vs. 196.6 min, p < 0.001). Local recurrence occurred in 8 and 5 patients, respectively (p > 0.05). Distant metastasis occurred in 5 and 11 patients, respectively (p < 0.05). CONCLUSIONS: Adding TRACE in the preoperative standard treatment for LARC did not increase perioperative complications. In addition, it has the potential advantage of preventing distant metastasis. It is worthy of further application and promotion in clinical practice.

Genistein induces apoptosis by stabilizing intracellular p53 protein through an APE1-mediated pathway.

Genistein (GEN) has been previously shown to have a proapoptotic effect on cancer cells through a p53-dependent pathway, the mechanism of which remains unclear. One of its intracellular targets, APE1, protects against apoptosis under genotoxic stress and interacts with p53. In this current study, we explored the mechanism of the proapoptotic effect of GEN by examining the APE1-p53 protein-protein interaction. We initially showed that the p53 protein level was elevated in GEN-treated human non-small lung cancer A549 cells and cervical cancer HeLa cells. By examining both protein synthesis and degradation, we found that GEN enhances p53 intracellular stability by interfering with the interaction of APE1 and p53, which provided a plausible explanation for how GEN initiates apoptosis. Furthermore, we found that the interaction between APE1 and p53 is important for the degradation of p53 and is dependent on the redox domain of APE1 by utilizing the redox domain mutant APE1 C65A. Our data suggest that the degradation of wild-type p53 is blocked when the redox domain of APE1 is masked or interrupted. Based on this evidence, we hereby report a novel mechanism of p53 degradation through an APE1-mediated, redox-dependent pathway.

APE1 promotes antioxidant capacity by regulating Nrf-2 function through a redox-dependent mechanism.

APE1 is a multifunctional protein that has recently been implicated in protecting cells from oxidative stress. In the current study, we confirmed that APE1׳s effect on cellular antioxidant capacity is related to its redox activity through the use of an APE1 functional mutant, and we investigated the mechanism through which this multifunctional protein affects the function of the transcription factor Nrf-2 in regulating oxidative stress-induced genes. Using a pair of mutants for both the redox activity and the acetylation-regulated activity of APE1, in vitro assays showed that the redox activity of APE1 is crucial for its nuclear association with Nrf-2 and subsequent activation of Nrf-2׳s transcription of several downstream genes during oxidative challenge. Important oxidative stress genes are affected by APE1 redox activity, including Hmox1, Gstm1, and Txnrd1. In addition, utilizing human non-small-cell lung cancer sample tissue as well as a nude mouse xenograft model, we determined that APE1 expression levels are inversely correlated to oxidative stress in vivo. These findings indicated that interference with these crucial functions of APE1 shows promise in preventing resistance to certain radiotherapies and that further research is necessary to understand APE1׳s complex roles in regulating both the basal redox status and the oxidative stress state of the cellular environment.

Genistein alleviates radiation-induced pneumonitis by depressing Ape1/Ref-1 expression to down-regulate inflammatory cytokines.

The aim of the study was to investigate the role of genistein in alleviating radiation-induced pneumonitis(RIP) through down-regulating levels of the inflammatory cytokines by inhibiting the expression of apurinic/apyrimidinic endonuclease 1/redox factor-1 (Ape1/Ref-1). Fifty female C57BL/6J mice (8 weeks old) were randomly divided into a control group, a pure irradiation (IR) group and a genistein + IR group. At the four time points after IR, hematoxylin, and Masson's trichrome stainings were used to examine the pathological changes and collagen fiber deposition. Flow cytometry was used to detect reactive oxygen system (ROS) changes, EMSA was used to estimate the nuclear factor kappa B (NF-κB) transcriptional activities and an ELISA assay was used to measure the levels of TGF-ß1, IL-1ß, TNF-α, and IL-6 in the serum and bronchoalveolar lavage fluid (BALF) 2 weeks after IR.The pathological detection results showed acute inflammatory/fibrinoid exudation of the thoracic tissue after IR,which was significantly alleviated with genistein. The IR inducedan APE1 protein expression increase and NF-jB was effectively suppressed by genistein (P < 0.05). The induction of the inflammatory cytokines TGF-ß1, IL-1ß,TNF-α, and IL-6 by IR were in turn inhibited in the serum and BALF of the genistein-pretreated mice (P < 0.05). In addition, the ROS production was significantly boosted in the A549 cells after IR, which could be down-regulated by the pretreatment of genistein. The results demonstrate that genistein alleviates RIP by attenuating the inflammatory response in the initiation of RIP. A possible target of genistein is the Ape1/ref-1, which regulates key inflammatory cytokines by activating the NF-κB.

[Norman Bethune and field surgery of the Eighth Route Army].

With long-term war experience abroad, combined with the actual situation of health work in China, Bethune put forward a series of strategy and theory used in battlefield conditions of rescuing the wounded in China, such as "fire rescue, early debridement", "emergency blood transfusion in battlefield" and "the crowd blood bank", which effectively improved the rate of saving the battlefield wounded rate in the actual war. Combining with his own practice, he invented a variety of surgical instruments and equipment, such as "lugou bridge" medicine cabinet, "Bipp ointment", which have been widely used in the battlefield. He paid more attention to the construction of battlefield hospital, proposed the establishment of "Model Hospital" and "Special Surgery Hospital" in the rear of Anti-Japanese War, founded the health school, and wrote many battlefield medical books and skills data. Bethune trained a large number of medical personnel for the war front, laid the foundation for the field surgery education of the Eighth Route Army.

Identification and characterization of mitochondrial targeting sequence of human apurinic/apyrimidinic endonuclease 1.

Dually targeted mitochondrial proteins usually possess an unconventional mitochondrial targeting sequence (MTS), which makes them difficult to predict by current bioinformatics approaches. Human apurinic/apyrimidinic endonuclease (APE1) plays a central role in the cellular response to oxidative stress. It is a dually targeted protein preferentially residing in the nucleus with conditional distribution in the mitochondria. However, the mitochondrial translocation mechanism of APE1 is not well characterized because it harbors an unconventional MTS that is difficult to predict by bioinformatics analysis. Two experimental approaches were combined in this study to identify the MTS of APE1. First, the interactions between the peptides from APE1 and the three purified translocase receptors of the outer mitochondrial membrane (Tom) were evaluated using a peptide array screen. Consequently, the intracellular distribution of green fluorescent protein-tagged, truncated, or mutated APE1 proteins was traced by tag detection. The results demonstrated that the only MTS of APE1 is harbored within residues 289-318 in the C terminus, which is normally masked by the intact N-terminal structure. As a dually targeted mitochondrial protein, APE1 possesses a special distribution pattern of different subcellular targeting signals, the identification of which sheds light on future prediction of MTSs.

[Effect of substance P on the migration and differentiation of cultured epidermal stem cells to hair follicle in vitro].

OBJECTIVE: To investigate the effect of substance P (SP) on the migration and differentiation of epidermal stem cells (ESCs) to hair follicle, and its mechanism. METHODS: ESCs were cultured in vitro, and confirmed by positive staining of K19 and integrin beta1 with immunohistochemistry. SP was added into the culture of ESCs which were labelled with 5-BrdU, and the cell cultures were divided into control, 10(-5) mol/L SP, 10(-6) mol/L SP, and 10(-7) mol/L SP groups according to the different doses of SP addition. Cell suspension (0.3 ml) containing SP was injected into the dermis in the back of nude mice. Repeated injection of the equal amount of cell suspension in the same place was carried out on 4, 7, 10 and 14 days after first injection. The cells in control group received the same treatment but without SP. The skin specimens in the area of cell culture injection and the normal skin remote from cell injection were harvested for the histological examination and hair follicle counting by immunohistochemistry and electronmicroscope 28 days after injections. RESULTS: Hair follicles in scattered distribution were observed in 10(-5) mol/L SP group,but some of them were defective in development. Hypoplasic hair follicle and a few hair follicles with distinct structure were observed in 10(-5) mol/L SP group. Large amounts of hair follicles with distinct structure in deep dermis and subcutaneous tissue were observed in 10(-6) mol/L SP, 10(-7) mol/L SP groups, and some of them showed positive staining of brown BrdU in the hair root, and most of them showed positive staining of brown beta-catenin, but a few of them showed developmental defect. In contrast, hypoplasia of hair follicle underneath epidermis and deep layer of dermis with positive staining of brown BrdU and beta-catenin in epidermis were observed in control group. The number of hair follicles in 10(-6)mol/L SP, 10(-7) mol/L SP groups [(1.9 +/- 1.2 ), (1.3 +/- 0.8)] was obviously less than that in control group [(10. 5 +/- 1.2), P < 0.01]. CONCLUSION: SP can induce ESCs to migrate from the basal layer into hair follicle, and this effect is dependent on the SP concentration. SP can also elevate the expression of beta-catenin in ESCs,which induces its differentiation to hair follicles.

Fabrication of a molecular-level multilayer film on organic polymer surfaces via chemical bonding assembly.

A fresh multilayer film was fabricated on a molecular level and successfully tethered to the surface of a hydroxylated organic substrate via chemical bonding assembly (CBA). Sulfate anion groups (SO4-) were preintroduced onto the surface of biaxially oriented polypropylene (BOPP) films via a reference method. Upon hydrolysis of the SO4- groups, hydroxyl groups (--OH) were formed that subsequently acted as initial reagents for a series of alternate reactions with terephthalyl chloride (TPC) and bisphenol A (BPA). A stable and well-defined multilayer film was thus fabricated via the CBA method. As a result of the nanoscale multilayer fresh film being abundant with reactive groups, it is believed that the film and its fabrication method should provide a fundamental platform for further surface functionalization and direct the design of advanced materials with desired properties.