PRPS2-mediated modulation of the antitumor immune response in lung cancer through CCL2-mediated tumor-associated macrophages and myeloid-derived suppressor cells.

BACKGROUND: Phosphoribosyl pyrophosphate synthetase 2 (PRPS2) is known as an oncogene in many types of cancers, including lung cancer. However, its role in regulating tumor-associated macrophages (TAM) and myeloid-derived suppressor cells (MDSC) remains unclear. Our study aimed to explore the involvement of PRPS2 in TAM and MDSC regulation. METHODS: Stable Lewis lung cancer (LLC) cell lines were established using a lentivirus system. These LLC lines were then used to establish tumor model in mice. The levels of target genes were determined using qPCR, western blotting, and ELISA assays. The percentage of different immune cell types was analyzed using fluorescence-activated cell sorting. The chemotaxis ability of TAM and MDSC was evaluated using an in vitro transwell chemotaxis assay. RESULTS: Notably, PRPS2 was found to regulate the chemotaxis of TAM and MDSC in tumor cells, as evidenced by the positive correlation of PRPS2 expression levels and abundance of TAM and MDSC populations. In addition, the expression of CCL2, mediated by PRPS2, was identified as a key factor in the chemotaxis of TAM and MDSC, as evidenced by a significant reduction in macrophages and MDSC numbers in the presence of the CCL2 antibody. Furthermore, in vivo experiments confirmed the involvement of PRPS2 in mediating CCL2 expression. PRPS2 was also found to regulate immune cell infiltration into tumors, whereas knockdown of CCL2 reversed the phenotype induced by PRPS2 overexpression. In tumor tissues from mice implanted with LLC-PRPS2-shCCL2 cells, a notable increase in CD4+ and CD8+ T cell percentages, alongside a marked decrease in TAMs, M-MDSC, and PMN-MDSC, was observed. CONCLUSION: Taken together, PRPS2 plays a crucial role in modulating the antitumor immune response by reprogramming CCL2-mediated TAM and MDSC.

TCL1A+ B cells predict prognosis in triple-negative breast cancer through integrative analysis of single-cell and bulk transcriptomic data.

Triple-negative breast cancer (TNBC) is an aggressive subtype with limited treatment options and high mortality rates. It remains a prevailing clinical need to distinguish whether the patient can benefit from therapy, such as chemotherapy. By integrating single-cell and global transcriptome data, we have for the first time identified TCL1A+ B cell functions that are prognostically relevant in TNBC. This finding broadens the perspective of traditional tumor-infiltrating lymphocytes in predicting survival, especially the potential value of B cells in TNBC. Single-cell RNA-seq data from five TNBC patients were collected to identify the association between immune cell populations and clinical outcomes. Functional analysis was according to gene set enrichment analysis using pathways from MsigDB. Subsequently, the gene signature of TCL1A+ B cells based on differential expression genes of TCL1A+ B cells versus other immune cells was used to explore the correlation with tumor microenvironment (TME) and construct a prognostic signature using a non-parametric and unsupervised method. We identified TCL1A+ B cells as a cluster of B cells associated with clinical outcomes in TNBC. Functional analysis demonstrated its function in B cell activation and regulation of immune response. The highly enriched TCL1A+ B cell population was found to be associated with a thermal TME with anti-tumor effects. A high abundance of TCL1A+ B cell population is positively correlated with a favorable therapeutic outcome, as indicated by longer overall survival. The present study suggests that TCL1A+ B cells play a key role in the treatment and prognostic prediction of TNBC, although further studies are needed to validate our findings. Moreover, the integration of transcriptome data at various resolutions provides a viable approach for the discovery of novel prognostic markers.

Bakuchiol inhibits lung cancer by modulating tumor microenvironment and the expression of PD-L1.

Immune checkpoint therapy is an emerging frontier in cancer therapy. With the aim to develop an efficient herb derived compound to facilitate immune checkpoint therapy, here we investigate if a herb-derived compound, Bakuchiol (BAK), can be used to treat lung cancer and elucidate if BAK could serve as a PD-L1 regulator. To this end, a murine lung cancer model was established by subcutaneously inoculating murine Lewis lung carcinoma (LLC) cells. BAK of 5 to 40 mg/kg was used for treatment in vivo for 15 days. On Day 15, the population of CD4+ and CD8+ T cells, Treg cells. BAK could effectively inhibit tumor growth by starting treatment either on Day 0 or 6 after tumor inoculation at doses of 5-40 mg/kg. BAK treatment increased the population of cytotoxic immune cells (i.e., CD8+ T cells, and M1 macrophages), meanwhile decreasing pro-tumor immune cells (i.e., CD3+ T cells, Treg cells, and M2 macrophages). Anti-inflammatory cytokines, including IL1ß, IL2, IFNγ, TNF-α, IL4 and IL10 were upregulated by BAK. PD-L1 expression in the tumor was also lowered by BAK. AKT and STAT3 signaling were inhibited by BAK. BAK is an efficient agent in reducing LLC tumor growth. These data support the potential of BAK as a new drug for treating lung cancer by serving as a PD-L1 inhibitor that suppresses the activation of AKT and STAT3.

Synergism Effect of Dendrobine on Cisplatin in Treatment of H1299 by Modulating the Balance of Treg/Th17.

BACKGROUND: Non-small cell lung cancer (NSCLC) accounts for about 80% of lung cancers. Cisplatin is a broad-spectrum anti-cancer drug and is often used in combination with other drugs. Research suggests that dendrobine, a pyrrolizidine derivative alkaloid, exhibits antitumor activity in various cancers. This study explores the effect of dendrobine combined with cisplatin on NSCLC and its underlying molecular mechanism. METHODS: The effects of dendrobine combined with cisplatin on tumor progression were evaluated by xenograft model (in vivo) and clonogenic survival assay (in vitro) using H1299 cell line. Annexin V staining was used for detecting apoptotic cells. The population of T cells, B cells and other subpopulations in the peripheral blood was determined by flow cytometry. RESULTS: Dendrobine combined with cisplatin prolonged the survival of mice implanted with H1299 cells and reduced tumor volume compared with single drug application. However, dendrobine exhibited no effect on H1299 cells in clonal survival assays with or without cisplatin treatment and did not promote cisplatin-induced apoptosis in vitro. Importantly, dendrobine suppressed the regulatory T cells (Treg cells) and enhanced the T helper 17 cells (Th17 cells). Treatment of dendrobine significantly reduced Foxp3, and increased the level of IL-17 in serum. CONCLUSION: Dendrobine displayed a synergistic effect with cisplatin to exert anti-tumor effect in vivo, which might be achieved by modulating the balance of Treg/Th17 cells rather than regulating cell apoptosis.

LncRNA surfactant associated 1 activates large tumor suppressor kinase 1/Yes-associated protein pathway via modulating hypoxic exosome-delivered miR-4766-5p to inhibit lung adenocarcinoma metastasis.

LncRNA surfactant associated 1 (SFTA1P) exhibits low expression in non-small cell lung cancer (NSCLC) tissues as compared with that in adjacent tissues, and may play a suppressing role in NSCLC. However, the effect and mechanism of SFTA1P on the metastasis of lung adenocarcinoma (LUAD) remain undefined, which are thus investigated in this research. Herein, potential impacts of SFTA1P on LUAD were determined through the Cancer Genome Atlas (TCGA) database and Gene Expression Profiling Interactive Analysis (GEPIA). After knockdown/overexpression of SFTA1P, the metastatic ability of LUAD cells was evaluated by molecular biology experiments (cell counting kit-8 assay, scratch test, Transwell assay and Western blot). The effect of SFTA1P on Yes-associated protein (YAP) nuclear translocation was assessed by Western blot. Hypoxia-induced exosomes were extracted for LUAD metastasis analysis. The targeting relationship of SFTA1P/miR-4766-5p/large tumor suppressor kinase 1 (LATS1) was verified by dual-luciferase reporter assay and molecular biology experiments. Xenograft and lung metastasis models were constructed for in vivo validation. SFTA1P was lowly expressed in LUAD, which was associated with the poor prognosis of patients with LUAD. Up-regulated SFTA1P prevented the metastasis of LUAD cells and the nuclear translocation of YAP. Hypoxia-induced exosomes stimulated LUAD cell metastasis, but inhibited the SFTA1P and LATS1/YAP axes. MiR-4766-5p acted as an intermediate "bridge" for SFTA1P to regulate LATS1. SFTA1P repressed xenograft growth and LUAD cell metastasis. To sum up, SFTA1P activates hypoxic exosome-delivered miR-4766-5p through modulating LATS1/YAP pathway, thereby suppressing LUAD cell metastasis, which may serve as a suitable target for the LUAD therapy.

RET fusions as primary oncogenic drivers and secondary acquired resistance to EGFR tyrosine kinase inhibitors in patients with non-small-cell lung cancer.

BACKGROUND: RET fusions are rare oncogenic drivers in non-small cell lung cancer (NSCLC). While activating RET rearrangements are found in NSCLC patients harboring epidermal growth factor receptor (EGFR) genetic alterations at resistance to EGFR inhibitors, the extent to which co-occurring genomic alterations exist and how they might affect prognosis or therapy response is poorly understood. METHODS: Targeted next-generation sequencing (NGS) was used to assess 380 baseline patients with primary RET fusions and 71 EGFR-mutated NSCLC patients who acquired RET fusions after developing resistance to EGFR-tyrosine kinase inhibitors (EGFR-TKIs). RESULTS: Primary RET fusions were more likely associated with females and younger age, with KIF5B being the predominant fusion partner. In baseline patients, both SMAD4 (5.3% vs. 0.0%, P = 0.044) and MYC copy-number gain variants (6.9% vs. 0.0%, P = 0.009) were more frequently co-mutated with KIF5B-RET than CCDC6-RET. By contrast, CDKN2A (11.3% vs. 2.4%, P = 0.003) mutations were significantly enriched in CCDC6-RET-rearranged baseline patients. A significant increase in the proportion of CCDC6-RET was observed in acquired RET-rearranged patients (47.3% vs. 22.5%, P < 0.001). The median progression-free survival (PFS) of patients harboring RB1 and TP53 double-mutations (5.5 vs. 10.0 months, P = 0.020) or ERBB2 amplification (5.6 vs. 10.0 months, P = 0.041) was significantly shorter than the wild-type counterparts. Moreover, we identified that RET fusions were more likely associated with acquired resistance (AR) to third-generation EGFR-TKIs than previous generations of EGFR-TKIs. CONCLUSIONS: In conclusion, we depicted the mutational profiles of NSCLC patients who harbor RET fusions at baseline or after resistance to EGFR-TKIs. Furthermore, our results suggest that RET fusions mediate secondary resistance to third-generation EGFR-TKIs and might be associated with poor prognosis in patients with NSCLC.

Molecular landscape and therapeutic alterations in Asian soft-tissue sarcoma patients.

BACKGROUND: Soft-tissue sarcoma (STS) is a rare solid malignant tumor with numerous histologic subtypes. Current studies on targeted therapy for STS are in preclinical and early-phase trials. Genomic differences largely influence the prognosis of patients even with the same subtype. To investigate the genomic alterations (GAs) and the potential of targeted therapy in STS, we analyzed the genomic landscape, the therapeutic GAs, and biomarkers of immunotherapy in Chinese STS patients. METHODS: Targeted sequencing covering 425 genes was performed, from which we obtained the results of tissue samples from 351 Chinese STS patients of all ages covering different histologic subtypes. Bioinformatics analysis of altered genes with nonsynonymous mutations, copy-number variations, and gene fusions were performed. OncoKB therapeutic GAs and relevant biomarkers including TMB, MSI, and HRD were further examined for potential targeted therapy. RESULTS: In total, 2743 GAs were identified in 330 genes with a median of 6 (1-38) per case. The top 11 frequently altered genes were: TP53, MCL1, MDM2, CDK4, MYC, CDKN2A, GNAS, RB1, ATRX, CDKN2B, and FGFR1. OncoKB defined therapeutic GAs were found in 23 genes in 43% of the patients. In general, 9.4% of the patients had high-TMB, 2.8% had MSI, and 13.7% had HRD. A significant difference in the percentage of patients with OncoKB therapeutic GAs were observed between the most frequent two subtypes, leiomyosarcoma and liposarcoma. Altogether, 54% of the patients had the potential to respond to a targeted therapy. CONCLUSION: This study indicated the potential efficacy of targeted therapy on many STS patients, and also provided insight for novel precision therapy. The clinical efficacy of combining targeted therapy and immunotherapy can be further investigated.

Trajectories of serum α-fetoprotein and intermediate-stage hepatocellular carcinoma outcomes after transarterial chemoembolization: A longitudinal, retrospective, multicentre, cohort study.

Background: α-fetoprotein (AFP) response has been proven a key tumor marker for hepatocellular carcinoma (HCC), but its definition remains controversial. This study aims to characterize AFP trajectories after transarterial chemoembolization (TACE) and examine its impact on clinical outcomes. Methods: This longitudinal, multicenter, retrospective, cohort study examined data from the electronic medical record system of four hospitals in China between January 1, 2007 to December 31, 2016. A latent class growth mixed model was applied to distinguish potential AFP dynamic changing trajectories. The multivariable Cox models were used to calculate adjusted hazard ratios (aHRs) and 95% CIs for overall survival. Inverse-probability-of-treatment weighted analyses were performed to eliminate unmeasured confounders through marginal structural models. Findings: A total of 881 patients, who had intermediate-stage HCC with AFP repeatedly measured 3 to 10 times, were included in the study. Three distinct trajectories were identified using the latent class growth mixture model: high-rising (25.7%; n = 226), low-stable (58.7%; n = 517), and sharp-falling (AFP serological response, 15.6%; n = 138). Compared with the low-stable class, the aHRs for death were 5.13 (3.71, 7.10) and 0.52 (0.33, 0.81) for the high-rising and sharp-falling class, adjusted by gender, baseline major tumor size, intrahepatic lesions number, and logAFP(smooth). Furthermore, high-rising class had a significantly higher HR in the subgroup of female patients (10.60, 95%CI: 6.29, 17.86), age<55 (6.78, 95%CI: 4.79, 9.59) and Child-Pugh class B (23.01, 95%CI:8.07, 65.63) (P = 0.014, 0.046 and 0.033 for interaction, respectively). Trajectories of AFP had the highest relative importance of each parameter to survival, including largest tumor size, intrahepatic lesions number, Child-Pugh class, and baseline AFP. Interpretation: AFP trajectories were associated with overall survival for intermediate-stage HCC after TACE. Funding: The Natural Science Foundation of Fujian Province (Nos. 2018J01352, 2016J01576 and 2016J01586); the Science and Technology Innovation Joint Foundation of Fujian Province (Nos. 2017Y9125).

SNRPD1/E/F/G Serve as Potential Prognostic Biomarkers in Lung Adenocarcinoma.

Objectives: Sm proteins (SNRPB/D1/D2/D3/E/F/G), involved in pre-mRNA splicing, were previously reported in the tumorigenesis of several cancers. However, their specific role in lung adenocarcinoma (LUAD) remains obscure. Our study aims to feature abnormal expressions and mutations of genes for Sm proteins and assess their potential as therapeutic targets via integrated bioinformatics analysis. Methods: In this research, we explored the expression pattern and prognostic worth of genes for Sm proteins in LUAD across TCGA, GEO, UALCAN, Oncomine, Metascape, David 6.8, and Kaplan-Meier Plotter, and confirmed its independent prognostic value via univariate and multivariate cox regression analysis. Meanwhile, their expression patterns were validated by RT-qPCR. Gene mutations and co-expression of genes for Sm proteins were analyzed by the cBioPortal database. The PPI network for Sm proteins in LUAD was visualized by the STRING and Cytoscape. The correlations between genes for Sm proteins and immune infiltration were analyzed by using the "GSVA" R package. Results: Sm proteins genes were found upregulated expression in both LUAD tissues and LUAD cell lines. Moreover, highly expressed mRNA levels for Sm proteins were strongly associated with short survival time in LUAD. Genes for Sm proteins were positively connected with the infiltration of Th2 cells, but negatively connected with the infiltration of mast cells, Th1 cells, and NK cells. Importantly, Cox regression analysis showed that high SNRPD1/E/F/G expression were independent risk factors for the overall survival of LUAD. Conclusion: Our study showed that SNRPD1/E/F/G could independently predict the prognostic outcome of LUAD and was correlated with immune infiltration. Also, this report laid the foundation for additional exploration on the potential treatment target's role of SNRPD1/E/F/G in LUAD.

PRPS2 Enhances Resistance to Cisplatin via Facilitating Exosomes-mediated Macrophage M2 Polarization in Non-small Cell Lung Cancer.

BACKGROUND: Phosphoribosyl pyrophosphate synthetases 2 (PRPS2) is reported as an oncogene in various cancers. However, the role of PRPS2 in cisplatin (DDP) resistance of non-small cell lung cancer (NSCLC) remains unclear. The present study aimed to explore the effect of PRPS2 in DDP resistance of NSCLC. METHODS: mRNA expression levels of genes were detected by RT-PCR. Enzyme-linked immunosorbent assay (ELISA) and Western blot were used to detect protein expression levels. Cell viability was determined by the MTT assay and colony formation assay. Cell apoptosis was detected using nucleosome ELISA assay and caspase-3 activity assay. PRPS2 silencing was achieved using siRNA transfection. Exosomes of cultured cells were isolated through ultracentrifugation. RESULTS: Elevated PRPS2 was correlated with DDP resistance and poor prognosis in NSCLC patients. PRPS2 silencing enhanced sensitivity of DDP-resistant cells to DDP treatment. NSCLC cell-derived exosome induced M2 macrophage polarization. PRPS2 was enriched in the exosomes of NSCLC cells. Exosomal PRPS2 mediated M2 macrophage polarization to promote DDP resistance of NSCLC cells. CONCLUSIONS: In conclusion, PRPS2 potentiates resistance to DDP by promoting exosome-mediated macrophage M2 polarization in NSCLC.

Circ_0020123 Increases ZFX Expression to Facilitate Non-Small Cell Lung Cancer Progression by Sponging miR-142-3p.

BACKGROUND: Circular RNA (circRNA) is involved in the progression of various cancers and has been shown to be an important potential target for cancer therapy. Circ_0020123 has been found to act as oncogene to participate in the malignant progression of non-small cell lung cancer (NSCLC). Therefore, exploring new mechanisms of circ_0020123 regulating NSCLC progression will help us better understand its role in NSCLC. METHODS: Relative expression levels of circ_0020123, microRNA (miR)-142-3p, and zinc-finger protein X-linked (ZFX) in tissues and cells were determined by quantitative real-time PCR (qRT-PCR). Cell proliferation, apoptosis, migration and invasion were assessed using cell counting kit 8 (CCK8) assay, colony formation assay, flow cytometry and transwell assay. Western blot (WB) analysis was used to detect relative protein level. Besides, the interaction between miR-142-3p and circ_0020123 or ZFX was confirmed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. RESULTS: Our results showed that circ_0020123 was upregulated in NSCLC, and its knockdown could suppress NSCLC cell proliferation, migration, invasion, and promote apoptosis. Circ_0020123 was found to interact with miR-142-3p. The inhibition effect of circ_0020123 silencing on NSCLC progression could be reversed by miR-142-3p inhibitor. ZFX could be targeted by miR-142-3p. The silencing of ZFX could hinder the progression of NSCLC and abolish the promotion effect of miR-142-3p inhibitor on NSCLC progression. In addition, circ_0020123 silencing inhibited NSCLC tumorigenesis by the miR-142-3p/ZFX axis. CONCLUSION: These findings suggested that circ_0020123 might be a potential therapy target for NSCLC, which could promote NSCLC progression through regulating the miR-142-3p/ZFX axis.

Cetuximab Maintenance Therapy in Patients with Unresectable Wild-Type RAS and BRAF Metastatic Colorectal Cancer: A Single-Institute Prospective Study.

INTRODUCTION: Cetuximab plus FOLFIRI (leucovorin, fluorouracil, and irinotecan) is the preferred first-line therapy for RAS and BRAF wild-type (RBWT) metastatic colorectal cancer (mCRC). To counter chemotherapy-induced side effects, use of maintenance therapy is suggested. Therefore, we evaluated the efficacy and safety of cetuximab maintenance therapy in patients after effective completion of first-line induction therapy. METHODS: This prospective study enrolled untreated patients with mCRC RBWT who received first-line cetuximab plus FOLFIRI therapy. Following this, patients with treatment response either entered observation (stop treatment) or maintenance treatment 1 (cetuximab plus irinotecan) groups. After 6-12 cycles of maintenance treatment 1, patients entered maintenance treatment 2 (cetuximab only). If a patient progressed on maintenance 2, cetuximab plus FOLFIRI was reintroduced. The primary end point was failure-free survival (FFS), whereas the secondary end points included disease control rate (DCR), objective remission rate (ORR), and progression-free survival (PFS). Safety events were also evaluated. RESULTS: Among 79 enrolled patients, 72 completed first-line treatment effectively (DCR 91.1%, ORR 63.9%) and 44 entered maintenance 1 [median PFS 1 (mPFS, maintenance 1) 6.1 months, 95% confidence interval (CI) 6.0-6.2; DCR 56.8%; ORR 22.7%]. Of them, 21 entered maintenance treatment 2 (mPFS2 8.7 months, 95% CI 3.3-14.1; DCR 28.6%; ORR 4.8%). Median FFS (mFFS) was significantly longer in the maintenance 1 group compared with the observation group [12.7 vs. 3.0 months; hazard ratio (HR) 0.202, 95% CI 0.111-0.369; P < 0.001]. Overall, mFFS was 19.0 and 9.3 months in maintenance and observation groups, respectively (HR 0.211, 95% CI 0.117-0.380; P < 0.001). Rash acneiform, mucositis, and asthenia were commonly observed adverse events during maintenance treatment. CONCLUSION: Maintenance treatment with cetuximab after first-line therapy significantly improved FFS, with an acceptable safety profile in untreated patients with mCRC RBWT. TRIAL REGISTRATION: Retrospectively registered, 2019/10/02, Chinese Clinical Trial Registry, ChiCTR number 1900026360.

HIF-1-alpha links mitochondrial perturbation to the dynamic acquisition of breast cancer tumorigenicity.

Up-regulation of hypoxia-inducible factor-1α (HIF-1α), even in normoxia, is a common feature of solid malignancies. However, the mechanisms of increased HIF-1α abundance, and its role in regulating breast cancer plasticity are not fully understood. We have previously demonstrated that dimethyl-2-ketoglutarate (DKG), a widely used cell membrane-permeable α-ketoglutarate (α-KG) analogue, transiently stabilizes HIF-1α by inhibiting prolyl hydroxylase 2. Here, we report that breast cancer tumorigenicity can be acquired through prolonged treatment with DKG. Our results indicate that, in response to prolonged DKG treatment, mitochondrial respiration becomes uncoupled, leading to the accumulation of succinate and fumarate in breast cancer cells. Further, we found that an early increase in the oxygen flux rate was accompanied by a delayed enhancement of glycolysis. Together, our results indicate that these events trigger a dynamic enrichment for cells with pluripotent/stem-like cell markers and tumorsphere-forming capacity. Moreover, DKG-mediated metabolic reprogramming results in HIF-1α induction and reductive carboxylation pathway activation. Both HIF-1α accumulation and the tumor-promoting metabolic state are required for DKG-promoted tumor repopulation capacity in vivo. Our data suggest that mitochondrial adaptation to DKG elevates the ratio of succinate or fumarate to α-KG, which in turn stabilizes HIF-1α and reprograms breast cancer cells into a stem-like state. Therefore, our results demonstrate that metabolic regulation, with succinate and/or fumarate accumulation, governs the dynamic transition of breast cancer tumorigenic states and we suggest that HIF-1α is indispensable for breast cancer tumorigenicity.

Intermediary metabolite precursor dimethyl-2-ketoglutarate stabilizes hypoxia-inducible factor-1α by inhibiting prolyl-4-hydroxylase PHD2.

Hypoxia-inducible factor 1α (HIF-1α), a major mediator of tumor physiology, is activated during tumor progression, and its abundance is correlated with therapeutic resistance in a broad range of solid tumors. The accumulation of HIF-1α is mainly caused by hypoxia or through the mutated succinate dehydrogenase A (SDHA) or fumarate hydratase (FH) expression to inhibit its degradation. However, its activation under normoxic conditions, termed pseudohypoxia, in cells without mutated SDHA or FH is not well documented. Here, we show that dimethyl-2-ketoglutarate (DKG), a cell membrane-permeable precursor of a key metabolic intermediate, α-ketoglutarate (α-KG), known for its ability to rescue glutamine deficiency, transiently stabilized HIF-1α by inhibiting activity of the HIF prolyl hydroxylase domain-containing protein, PHD2. Consequently, prolonged DKG-treatment under normoxia elevated HIF-1α abundance and up-regulated the expression of its downstream target genes, thereby inducing a pseudohypoxic condition. This HIF-1α stabilization phenotype is similar to that from treatment of cells with desferrioxamine (DFO), an iron chelator, or dimethyloxalyglycine (DMOG), an established PHD inhibitor, but was not recapitulated with other α-KG analogues, such as Octyl-2KG, MPTOM001 and MPTOM002. Our study is the first example of an α-KG precursor to increase HIF-1α abundance and activity. We propose that DKG acts as a potent HIF-1α activator, highlighting the potential use of DKG to investigate the contribution of PHD2-HIF-1α pathway to tumor biology.

[Clinicopathological features and long-term results of surgical therapy of early gastric cancer].

OBJECTIVE: To investigate factors implicated in the relapse of early gastric cancer (EGC), and to explore the mode of lymphadenectomy (over-D(1) vs D(2)) for EGC patients. METHODS: The data of 161 EGC patients, diagnosed from Jul. 1979 to Aug. 2004, were investigated in the study retrospectively. RESULTS: One hundred and sixty-one EGC cases accounted for 6.0% of the total gastric cancer cases during the same period (161/2694). D(2) lymphadenectomy were performed in 112/161 cases, and over-D(1) in 49/161. Among these cases, 9 developed distant metastases (7 in liver and 2 in bone), 3 local recurrences in remaining gastric, and 3 lymph node metastases. The 5 and 10-year survival rates were 90.7% and 89.8% respectively. The risk factors associated with recurrence included lymph node metastases, depth of invasion, lymphatic involvement, number of tumors, vessel involvement, tumor size, age and lymphadenectomy (P<0.05) through univariate analysis. Further multivariate analysis showed that lymph node metastases, vessel involvement, gross type and extent of lymphadenectomy as independent effective factors for recurrence. Compared with over-D(1) mode, D(2) mode conferred a significantly increased cumulative survival for cancer invaded the submucosa. No significant difference in cumulative survival for mucosa invasive EGC was found between over-D(1) and D(2) modes. CONCLUSIONS: Lymph node metastases and vessel involvement act as independent risk factors for recurrence of EGC. Adversely, protrusion lesion and D(2) lymphadenectomy are shown as protection factors for recurrence of EGC. Standard D(2) lymphadenectomy should be carried out in EGC with submucosal invasion or positive sentinel nodes or depressed lesions (IIc + III).