Targeting PP2A with lomitapide suppresses colorectal tumorigenesis through the activation of AMPK/Beclin1-mediated autophagy

Colorectal cancer (CRC) is one of the most common malignancies worldwide, and effective therapy remains a challenge. In this study, we take advantage of a drug repurposing strategy to screen small molecules with novel anticancer activities in a small-molecule library consisting of 1056 FDA-approved drugs. We show, for the first time, that lomitapide, a lipid-lowering agent, exhibits antitumor properties in vitro and in vivo. Activated autophagy is characterized as a key biological process in lomitapide-induced CRC repression. Mechanistically, lomitapide stimulated mitochondrial dysfunction-mediated AMPK activation, resulting in increased AMPK phosphorylation and enhanced Beclin1/Atg14/Vps34 interactions, provoking autophagy induction. Autophagy inhibition or AMPK silencing significantly abrogated lomitapide-induced cell death, indicating the significance of AMPK-regulated autophagy in the antitumor activities of lomitapide. More importantly, PP2A was identified as a direct target of lomitapide by limited proteolysis-mass spectrometry (LiP-SMap), and the bioactivity of lomitapide was attenuated in PP2A-deficient cells, suggesting that the anticancer effect of lomitapide occurs in a PP2A-dependent manner. Taken together, the results of the study reveal that lomitapide can be repositioned as a potential therapeutic drug for CRC treatment.

Targeted Immunotherapies in Gastrointestinal Cancer: From Molecular Mechanisms to Implications

Gastrointestinal cancer is a leading cause of cancer-related mortality and remains a major challenge for cancer treatment. Despite the combined administration of modern surgical techniques and chemoradiotherapy (CRT), the overall 5-year survival rate of gastrointestinal cancer patients in advanced stage disease is less than 15%, due to rapid disease progression, metastasis, and CRT resistance. A better understanding of the mechanisms underlying cancer progression and optimized treatment strategies for gastrointestinal cancer are urgently needed. With increasing evidence highlighting the protective role of immune responses in cancer initiation and progression, immunotherapy has become a hot research topic in the integrative management of gastrointestinal cancer. Here, an overview of the molecular understanding of colorectal cancer, esophageal cancer and gastric cancer is provided. Subsequently, recently developed immunotherapy strategies, including immune checkpoint inhibitors, chimeric antigen receptor T cell therapies, tumor vaccines and therapies targeting other immune cells, have been described. Finally, the underlying mechanisms, fundamental research and clinical trials of each agent are discussed. Overall, this review summarizes recent advances and future directions for immunotherapy for patients with gastrointestinal malignancies.

Expression changes of inflammatory cytokines TNF-α, IL-1β and HO-1 in hematoma surrounding brain areas after intracerebral hemorrhage

To study the expression changes of inflammatory factors heme oxygenase-1 (HO-1), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) in intracerebral hemorrhage (ICH), brain tissues surrounding hematoma were collected from ICH patients. The expressions of HO-1, TNF-α, IL- 1β, and other genes were examined at different time points of ICH. Changes in HO-1, TNF-α, and IL-1β positive cell numbers after ICH were detected by immunohistochemical staining. The results showed that the expressions of HO-1, TNF-α, and IL-1β had no significant changes in brain tissues surrounding hematoma within 6 hours after ICH (P > 0.05). Their expressions during 6-24 hours and 24-72 hours after ICH increased constantly. After reaching the peak, they remained steady or slightly decreased after 72 hours. The dynamic expression changes of HO-1, TNF-α, and IL-1β were observed and their development trends were interfered timely to alleviate the secondary neurological impairment after ICH, which was significant to prevent ICH.

Study of the relationship between the expression of nerve growth factor and aneurysm formation and prognosis

We sought to investigate the effect of nerve growth factor (NGF) expression on the formation and prognosis of cerebral aneurysms. Forty-eight cases were selected following a diagnosis of cerebral aneurysm using computed tomography angiography and surgical confirmation. Thirty-four cases of healthy deaths were also chosen. The tissue was tested for NGF expression changes by reverse-transcription PCR, Western blot and histopathology, and NGF expression was compared between the cerebral aneurysm and healthy groups. The expression level of NGF in cerebral aneurysm tissue was significantly increased over that observed in control tissue. The abnormal expression of NGF is related to cerebral aneurysms. The elevated expression of NGF in cerebral aneurysms may be associated with a poor prognosis.

Relationship between abnormal NOS expression and the pathogenesis of cerebral aneurysm

We sought to investigate the relationship between abnormal expression of nitric oxide synthase (NOS) and pathogenesis of cerebral aneurysm. Brain tissues were collected from 36 patients with cerebral aneurysm confirmed by computer tomography with angiography or neurosurgical therapy. The control group consisted of 25 patients of similar age who had no vascular diseases, as confirmed by magnetic resonance imaging. Samples of cortical arterioles were collected. The structure of the aneurysms was detected by hematoxylin and eosin staining, and the expression of inducible NOS was detected by immunohistochemistry. NOS expression was significantly higher in the patient group than in the control group (patients: 30/36 strongly positive; control: 0/25 strongly positive; P < 0.05). In conclusion, the pathogenesis underlying cerebral aneurysm may be due to abnormal expression of NOS, degradation of the extracellular matrix, aggravation of a pro-inflammatory reaction, or a deficiency in arterial elasticity layer synthesis. These changes may result in a deficiency in vascular remodeling.

Anaerobic digestibility of beef hooves with swine manure or slaughterhouse sludge

Anaerobic digestion is an effective method for treating animal by-products, generating at the same time green energy as methane (CH4). However, the methods and mechanisms involved in anaerobic digestion of α-keratin wastes like hair, nails, horns and hooves are still not clear. In this study we investigated the feasibility of anaerobically co-digesting ground beef hooves in the presence of swine manure or slaughterhouse sludge at 25 °C using eight 42-L Plexiglas lab-scale digesters. Our results showed addition of beef hooves statistically significantly increased the rate of CH4 production with swine manure, but only increased it slightly with slaughterhouse sludge. After 90-day digestion, 73% of beef hoof material added to the swine manure-inoculated digesters had been converted into CH4, which was significantly higher than the 45% level achieved in the slaughterhouse sludge inoculated digesters. BODIPY-Fluorescent casein staining detected proteolytic bacteria in all digesters with and without added beef hooves, and their relative abundances corresponded to the rate of methanogenesis of the digesters with the different inocula. Fluorescence in situ hybridization in combination with BODIPY-Fluorescent casein staining identified most proteolytic bacteria as members of genus Alkaliphilus in the subfamily Clostridiaceae 2 of family Clostridiaceae. They thus appear to be the bacteria mainly responsible for digestion of beef hooves.

Sustained elevation of Epstein-Barr virus antibody levels preceding clinical onset of nasopharyngeal carcinoma

We have monitored Epstein–Barr virus (EBV) IgA antibody levels of 39 nasopharyngeal carcinoma (NPC) cases for up to 15 years before clinical onset of NPC, and assessed preclinical serologic status of another 68 cases. Our results identify a serologic window preceding diagnosis when antibody levels are raised and sustained. This window can persist for as long as 10 years, with a mean duration estimated to as 37±28 months. Ninety-seven of these 107 NPC cases exhibited such a window. Cases that did not may reflect individual antibody response to EBV. Serologic screening at enrollment identified those cases who had already entered the window and became clinically manifested earlier (median=28 months) than those who entered the window after enrollment (median=90 months). The former account for 19 of 21 cases diagnosed within 2 years of screening. Nasopharyngeal carcinoma risk levels among seropositive subjects were also highest during this period. Both prediction rates and risk levels declined thereafter; cases detected at later times were composed of increasing proportions of individuals who entered the serological window after screening. Our findings establish EBV antibody as an early marker of NPC and suggest that repeated screening to monitor cases as they enter this window has considerable predictive value, with practical consequences for cancer treatment.

Tradescantia bioassays for the determination of genotoxicity of water in the Panlong River, Kunming, People's Republic of China

The Panlong river passes through Kunming City and receives a large quantity of municipal sewage and wastewater from industrial effluent. Along the river, 20 sites were selected to collect water samples to assess the genotoxicity using two Tradescantia assays, the micronucleus (Trad-MCN) and the stamen-hair-mutation (Trad-SHM) assays. The lowest frequencies in the Trad-MCN assay and the Trad-SHM assay are 3.19 MCN/100 tetrads and 1.32 M/1000 stamen hairs, respectively. In the water samples obtained from the Songhua Reservoir, the MCN frequencies and mutation rates are not statistically significantly different from the data found for the negative control (2.49 MCN/100 tetrads and 0.71 M/1000 stamen hairs). Among the other water samples, 19 in Trad-MCN assay and 17 in Trad-SHM assay show significantly higher genotoxicity than the control. The highest genotoxicity was in samples No. 19 for the MCN assay (8.73 MCN/100 cells), over three times higher than the negative control, and in sample No. 11 for the SHM assay (4.30 M/1000), six times higher than the negative control, and were about the same as for the positive control (10.0 mg/l NaN3, 9.28 MCN/100 tetrads and 7.44 SHM/1000 stamen hairs), respectively. The peak frequencies for the Trad-MCN assays were observed in the water samples obtained from the sites that were near industrial and municipal wastewater that ran into the river as effluent. In general, the frequency of MCN and SHM mutations increased where the river passed through Kunming. The Trad-MCN assay seemed more sensitive than that of the Trad-SHM assay in detecting genotoxicity of the river water pollution.