HER2+ advanced gastric cancer: Current state and opportunities (Review).

Human epidermal growth factor receptor 2 (HER2)+ gastric cancer (GC) is a distinct subtype of GC, accounting for 10­20% of all cases of GC. Although the development of the anti­HER2 monoclonal antibody trastuzumab has markedly improved response rates and prognosis of patients with HER2+ advanced GC (AGC), drug resistance remains a considerable challenge. Therefore, dynamic monitoring of HER2 expression levels can facilitate the identification of patients who may benefit from targeted therapy. Besides trastuzumab, DS­8201 and RC48 have been applied in the treatment of HER2+ AGC, and several novel anti­HER2 therapies are undergoing preclinical/clinical trials. At present, combination immunotherapy with anti­HER2 agents is used as the first­line treatment of this disease subtype. New promising approaches such as chimeric antigen receptor T­cell immunotherapy and cancer vaccines are also being investigated for their potential to improve clinical outcomes. The current review provides new insights that will guide the future application of anti­HER2 therapy by summarizing research progress on targeted therapy drugs for HER2+ AGC and combination treatments.

Divergent effects of intensified precipitation on primary production in global drylands.

Amplification of hydrological cycle under warming climate is anticipated to result in intensified precipitation characterized by fewer, more intense events and correspondingly longer dry intervals between events, even without major changes in annual total precipitation. Vegetation gross primary production (GPP) in drylands is highly responsive to intensified precipitation, however, how intensified precipitation influences GPP in global drylands is not well understood. Based on multiple satellite datasets from 2001 to 2020 and in-situ measurements, we investigated the effects of intensified precipitation on global drylands GPP under diverse annual total precipitation along the bioclimate gradient. Dry, normal, and wet years were identified as years with annual precipitation anomalies below, within, and above the range of one standard deviation. Intensified precipitation led to increases or decreases of GPP during dry or normal years, respectively. However, such effects were largely weakened during wet years. The responses of GPP to intensified precipitation were mirrored by soil water availability, as intensified precipitation enhanced root zone soil moisture, and thus vegetation transpiration and precipitation use efficiency during dry years. During wet years, root zone soil moisture showed less response to changed precipitation intensity. Land cover types and soil texture regulated the magnitude of the effects along the bioclimate gradient. Under intensified precipitation, shrubland and grassland distributed in drier region with coarse soil texture showed greater increases of GPP during dry years. As global precipitation will likely further intensify, the impacts of intensified precipitation on dryland carbon uptake capacity will be highly diverse along the bioclimate gradients.

Efficacy of regorafenib combined with PD-1 inhibitors in elderly patients with advanced metastatic colorectal cancer.

OBJECTIVE: This is the first clinical study that wants to investigate the treatment patterns, clinical outcomes, and prognostic factors of regorafenib plus PD-1 inhibitors therapy in Chinese elderly patients with advanced colorectal cancer. METHODS: A cohort of metastatic colorectal cancer patients 60 years or older who received treatment with regorafenib combined with PD-1 inhibitors was included in our analysis. The endpoints included overall survival (OS), progression-free survival (PFS), and prognostic factors. RESULTS: In total, 24 patients were enrolled with the median age of 68 years, and 62.5% were female. The median OS and PFS were 15.03 months (95% CI 7.0-23.0) and 4.0 months (95% CI 1.8-6.2), respectively. The objective response rate was 8.3%, and the disease control rate was 70.8%. Patients previously treated with regorafenib had a longer median PFS than those without (6.3 versus 2.8 months). In terms of final daily doses, it showed a trend toward better PFS (median PFS was 10.0 months) in high-dose group (daily dose above 80 mg of regorafenib) compared to low-dose group (daily dose no more than 80 mg of regorafenib) (median PFS was 3.5 months). CONCLUSIONS: This real-world evidence confirms that Chinese elderly patients with advanced colorectal cancer may benefit from the treatment of regorafenib combined with PD-1 inhibitors, similarly with this combination therapy strategies in all age patients.

Identifying gene variants underlying the pathogenesis of diabetic retinopathy based on integrated genomic and transcriptomic analysis of clinical extreme phenotypes.

Diabetic retinopathy (DR) is a common complication and the leading cause of blindness in patients with type 2 diabetes. DR has been shown to be closely correlated with blood glucose levels and the duration of diabetes. However, the onset and progression of DR also display clinical heterogeneity. We applied whole-exome sequencing and RNA-seq approaches to study the gene mutation and transcription profiles in three groups of diabetic patients with extreme clinical phenotypes in DR onset, timing, and disease progression, aiming to identify genetic variants that may play roles in the pathogenesis of DR. We identified 23 putatively pathogenic genes, and ingenuity pathway analysis of these mutated genes reveals their functional association with glucose metabolism, diabetic complications, neural system activity, and dysregulated immune responses. In addition, ten potentially protective genes were also proposed. These findings shed light on the mechanisms underlying the pathogenesis of DR and may provide potential targets for developing new strategies to combat DR.

Overview on the Role of E-Cadherin in Gastric Cancer: Dysregulation and Clinical Implications.

Gastric cancer is the fifth most common cancer and the third most common cause of cancer death all over the world. E-cadherin encoded by human CDH1 gene plays important roles in tumorigenesis as well as in tumor progression, invasion and metastasis. Full-length E-cadhrin tethered on the cell membrane mainly mediates adherens junctions between cells and is involved in maintaining the normal structure of epithelial tissues. After proteolysis, the extracellular fragment of the full-length E-cadhein is released into the extracellular environment and the blood, which is called soluble E-cadherin (sE-cadherin). sE-cadherin promots invasion and metastasis as a paracrine/autocrine signaling molecule in the progression of various types of cancer including gastric cancer. This review mainly summarizes the dysregulation of E-cadherin and the regulatory roles in the progression, invasion, metastasis, and drug-resistance, as well as its clinical applications in diagnosis, prognosis, and therapeutics of gastric cancer.

Knockdown of Kremen2 Inhibits Tumor Growth and Migration in Gastric Cancer.

Kremen2 (Krm2) plays an important role in embryonic development, bone formation, and tumorigenesis as a crucial regulator of classical Wnt/ß-catenin signaling pathway. However, the role of Krm2 in gastric cancer is not clear. The aim of this study was to explore the regulatory role of Krm2 in the tumorigenesis and metastasis of gastric cancer. It was demonstrated that, compared to para-cancerous tissues, Krm2 was significantly up-regulated in gastric cancer tissues and was positively correlated with the pathological grade of gastric cancer patients. Given that Krm2 is abundantly expressed in most tested gastric cancer cell lines, Krm2 knockdown cell models were established and further used to construct mice xenograft model. After knocking down Krm2, both the cell survival in vitro and tumorigenesis in vivo of gastric cancer cells were inhibited. At the same time, knockdown of Krm2 induced apoptosis, cell cycle arrest at G2/M phase and repression of migration in gastric cancer cells in vitro. Mechanistically, we found that knockdown of Krm2 suppressed PI3K/Akt pathway. Therefore, we revealed the novel role and the molecular mechanism of Krm2 in promoting the tumorigenesis and metastasis in gastric cancer. Krm2 can be a potent candidate for designing of targeted therapy.

Seasonal and interannual variations in carbon fluxes in East Asia semi-arid grasslands.

Semiarid regions have substantial interannual variation in carbon exchange between terrestrial ecosystem and atmosphere but the diverse responses of carbon fluxes to climate variability are poorly known. We compared carbon exchange processes and the responses to environmental factors in a meadow steppe at Tongyu (TY) and a typical steppe at Maodeng (MD) using long-term continuous eddy covariance measurements. TY precipitation was 25% greater than MD. Both grasslands had interannual fluctuations of carbon sink and source and acted as weak carbon sinks averagely (-22.9 ±â€¯41.0 gCm-2 yr-1 for TY and - 11.8 ±â€¯45.0 gCm-2 yr-1 for MD). The seasonal dynamics of carbon fluxes were significantly related to water availability at MD but more strongly related to air temperature at TY. During dry years, the controlling effect of water availability on carbon fluxes increased. Summer precipitation and soil moisture played key roles in the interannual variations in carbon fluxes in both grasslands. At MD, net carbon uptake was negatively related to summer air temperature likely because warming induced water deficit decreased photosynthesis. Greenness index derived from PhenoCam images captured key phenological phases and diverse magnitude of canopy dynamics. The index was correlated with seasonal and annual variations in carbon fluxes at both grasslands, suggesting the potential of PhenoCam for monitoring the spatial and temporal variations in canopy dynamics in different semiarid grasslands.

GLP-1/GLP-1R Signaling in Regulation of Adipocyte Differentiation and Lipogenesis.

BACKGROUND/AIMS: The aim of this study was to determine the direct role of liraglutide (LG) in adipogenesis and lipid metabolism. METHODS: Lipid accumulation was evaluated by oil red O staining, quantitative real-time PCR (qPCR) was performed to determine glucagon-like peptide 1 receptor (GLP-1R), fatty acid synthase (FASN) and adipose triglyceride lipase (ATGL) expression in 3T3-L1 preadipocytes, differentiated adipocytes and in adipose tissues from mice. The effects of LG on 3T3-L1 adipogenesis and lipid metabolism were analyzed with qPCR, Western Blotting, oil red O staining, immunohistochemistry (IHC) and immunofluorescence (IF). All measurements were performed at least three times. RESULTS: LG increased the expression of differentiation marker genes and lipid accumulation during preadipocyte differentiation. In differentiated adipocytes, LG decreased FASN expression, and simultaneously led to CREB phosphorylation and ERK1/2 activation which were abolished by a GLP-1R antagonist, exendin (9-39). LG induced-FASN down-regulation was partially reversed by PKA and ERK1/2 inhibitors. Consistent with above in vitro findings, LG treatment significantly reduced FASN expression in visceral adipose tissues of ob/ob mice, and reduced body weight gain. CONCLUSION: LG promotes preadipocytes differentiation, and inhibits FASN expression in adipocytes. LG induced down-regulation of FASN is at least partially mediated by PKA and MAPK signaling pathways.

Hydrogen sulfide improves diabetic wound healing in ob/ob mice via attenuating inflammation.

BACKGROUND: The proposed mechanisms of impaired wound healing in diabetes involve sustained inflammation, excess oxidative stress and compromised agiogenesis. Hydrogen sulfide (H2S) has been reported to have multiple biological activities. We aim to investigate the role of H2S in impaired wound healing in ob/ob mice and explore the possible mechanisms involved. PROCEDURES: Full-thickness skin dorsal wounds were created on ob/ob mice and C57BL/6 mice. Cystathionine-γ-lyase (CSE) expression and H2S production were determined in granulation tissues of the wounds. Effects of NaHS on wound healing were evaluated. Inflammation and angiogenesis in granulation tissues of the wounds were examined. RESULTS: CSE expression, and H2S content were significantly reduced in granulation tissues of wounds in ob/ob mice compared with control mice. NaHS treatment significantly improved wound healing in ob/ob mice, which was associated with reduced neutrophil and macrophage infiltration, decreased production of tumor necrosis factor (TNF)-α, interleukin (IL)-6. NaHS treatment decreased metalloproteinase (MMP)-9, whereas increased collagen deposition and vascular-like structures in granulation tissues of wounds in ob/ob mice. CONCLUSION: CSE down-regulation may play a role in the pathogenesis of diabetic impaired wound healing. Exogenous H2S could be a potential agent to improve diabetic impaired wound healing by attenuating inflammation and increasing angiogenesis.

Cytochrome P450 (CYP) epoxygenases as potential targets in the management of impaired diabetic wound healing.

Epoxyeicosatrienoic acids (EETs) are the epoxidation products of arachidonic acid catalyzed by cytochrome P450 (CYP) epoxygenases, which possess multiple biological activities. In the present study, we aimed to explore the role and effects of CYP epoxygenases/EETs in wound healing in ob/ob mice. Full-thickness skin dorsal wounds were made on ob/ob mice and C57BL/6 control mice. The mRNA and protein expression of CYP epoxygenases were determined in granulation tissues of wounds. Effects of EETs on wound healing were evaluated. Inflammation and angiogenesis in wounds were also observed. Compared with C57BL/6 mice, the mRNA and protein expression of CYP2C65 and CYP2J6 in the granulation tissues in ob/ob mice were significantly reduced. 11,12-EET treatment significantly improved wound healing in ob/ob mice, whereas 14,15-EEZE, an EET antagonist, showed the opposite effect. 11,12-EET treatment decreased neutrophil and macrophage infiltration to the wound sites, resulting in reduced production of inflammatory cytokines, decreased MMP-9 expression, and increased collagen accumulation in the granulation tissues of ob/ob mice. In addition, 11,12-EET increased angiogenesis in the granulation tissues of wounds in ob/ob mice. These findings indicate that reduced expression of CYP epoxygenases may contribute to impaired diabetic wound healing, and exogenous EETs may improve diabetic wound healing by modulating inflammation and angiogenesis.

Effects of hydrogen sulfide on high glucose-induced glomerular podocyte injury in mice.

The aim of this study was to assess the effects of hydrogen sulfide on high glucose-induced mouse podocyte (MPC) injury and the underlying mechanisms. Mouse podocytes were randomly divided into 4 groups, including high glucose (HG), normal glucose (NG), normal glucose + DL-propargylglycine (PPG), and high glucose + NaHS (HG + NaHS) groups for treatment. Then, ZO-2, nephrin, ß-catenin, and cystathionine γ-lyase (CSE) protein expression levels were determined by western blot. We found that high glucose significantly reduced nephrin, ZO-2, and CSE expression levels (P<0.05), and overtly elevated ß-catenin amounts (P<0.05), in a time-dependent manner. Likewise, PPG at different concentrations in normal glucose resulted in significantly lower CSE, ZO-2, and nephrin levels (P<0.05), and increased ß-catenin amounts (P<0.05). Interestingly, significantly increased ZO-2 and nephrin levels, and overtly reduced ß-catenin amounts were observed in the HG + NaHS group compared with HG treated cells (P<0.01). Compared with NG treated cells, decreased ZO-2 and nephrin levels and higher ß-catenin amounts were obtained in the HG + NaHS group. In conclusion,CSE downregulation contributes to hyperglycemia induced podocyte injury, which is alleviated by exogenous H2S possibly through ZO-2 upregulation and the subsequent suppression of Wnt/ß-catenin pathway.