IQGAP1诱导肝细胞肝癌干性促进血管生成拟态形成的实验研究

目的:检测IQGAP1在肝细胞肝癌(hepatocellular carcinoma,HCC)组织中的表达并研究其对肝癌细胞血管生成拟态形成能力的影响。方法:采用免疫组织化学法检测2001年1月至2009年1月天津医科大学肿瘤医院180例肝癌组织中IQGAP1的表达,采用CD31/PAS双染法检测肝癌中血管生成拟态的情况,并分析IQGAP1与血管生成拟态之间的相关性;将IQGAP1过表达质粒和干扰质粒分别转染至肝癌细胞系Hep G2和SMMC7721中,使用Western blot法检测转染后Hep G2和SMMC7721细胞中干性相关蛋白CD133、CD44、Sox2和ALDH1的表达情况;细胞功能学实验检测IQGAP1对迁移侵袭、增殖、管道形成能力的影响。结果:免疫组织化学结果显示IQGAP1定位于细胞膜或细胞质,其表达与肿瘤分级、转移和血管生成拟态形成相关(P<0.05)。在Hep G2细胞中上调IQGAP1,增强了Hep G2细胞迁移侵袭、增殖、管道行成能力,促进了干性相关蛋白CD133、CD44、Sox2和ALDH1的表达;在SMMC7721细胞中下调IQGAP1,抑制了SMMC7721细胞迁移侵袭、增殖、管道行成能力(P<0.05),降低了上述干性相关蛋白的表达。结论:IQGAP1表达升高促进了HCC的恶性生物学行为,IQGAP1可能通过诱导HCC干性来促进血管生成拟态形成。

Cancer stem-like cells directly participate in vasculogenic mimicry channels in triple-negative breast cancer

Objective: Vasculogenic mimicry(VM) channels that are lined by tumor cells are a functional blood supply in malignant tumors.However, the role of VM-initiating cells remains poorly understood. Cancer stem-like cells(CSCs) are positively correlated with VM. In this study, triple-negative breast cancer(TNBC) enriched with CSCs was used to investigate the relationship between VM and CSCs.Methods: The expression of several CSC markers was detected by immunohistochemistry in 100 human breast cancer samples.The clinical significance of CSC markers and the relationship between VM, CSCs, breast cancer subtypes, and VM-associated proteins were analyzed. CD133+ and ALDH+ human and mouse TNBC cells were isolated by FACS to examine the ability of VM formation and the spatial relationship between VM and CSCs.Results: CSCs were associated with TNBC subtype and VM in human invasive breast cancer. CSCs in TNBC MDA-MB-231 cells formed more VM channels and expressed more molecules promoting VM than the non-TNBC MCF-7 cells in vitro. MDA-MB-231 cells that encircled VM channels on Matrigel expressed CD133. Moreover, CSCs were located near VM channels in the 3D reconstructed blood supply system in human TNBC grafts. The CD133+ and ALDH+ cells isolated from TA2 mouse breast cancer formed more VM channels in vivo.Conclusions: CSCs line VM channels directly. Additionally, CSCs provide more VM-related molecules to synergize VM formation. The signaling pathways that control CSC differentiation may also be potential treatment targets for TNBC.

Hypoxic microenvironment induced spatial transcriptome changes in pancreatic cancer

Objective: Hypoxia is a significant feature of solid tumors, including pancreatic ductal adenocarcinoma(PDAC). It is associated with tumor invasion, metastasis, and drug resistance. However, the spatial distribution of hypoxia-related heterogeneity in PDAC remains unclear.Methods: Spatial transcriptomics(STs), a new technique, was used to investigate the ST features of engrafted human PDAC in the ischemic hind limbs of nude mice. Transcriptomes from ST spots in the hypoxic tumor and the control were clustered using differentially-expressed genes. These data were compared to determine the spatial organization of hypoxia-induced heterogeneity in PDAC. Clinical relevance was validated using the Tumor Cancer Genome Atlas and KM-plotter databases. The CMAP website was used to identify molecules that may serve as therapeutic targets for PDAC.Results: ST showed that the tumor cell subgroups decreased to 7 subgroups in the hypoxia group, compared to 9 subgroups in the control group. Different subgroups showed positional characteristics and different gene signatures. Subgroup 6 located at the invasive front showed a higher proliferative ability under hypoxia. Subgroup 6 had active functions including cell proliferation, invasion, and response to stress. Expressions of hypoxia-related genes, LDHA, TPI1, and ENO1, induced changes. CMAP analysis indicated that ADZ-6482, a PI3 K inhibitor, was targeted by the invasive subgroup in hypoxic tumors.Conclusions: This study is the first to describe hypoxic microenvironment-induced spatial transcriptome changes in PDAC, and to identify potential treatment targets for PDAC. These data will provide the basis for further investigations of the prognoses and treatments of hypoxic tumors.

ENO1 expression and Erk phosphorylation in PDAC and their effects on tumor cell apoptosis in a hypoxic microenvironment

Objective: Hypoxia is an important feature of pancreatic ductal adenocarcinoma(PDAC). Previously, we found that hypoxia promotes ENO1 expression and PDAC invasion. However, the underlying molecular mechanism was remains unclear.Methods: The relationship between ENO1 expression and clinicopathological characteristics was analyzed in 84 patients with PADC. The effects of CoCl2-induced hypoxia and ENO1 downregulation on the apoptosis, invasion, and proliferation of PDAC cells were evaluated in vitro and in vivo. Hypoxia-and ENO1-induced gene expression was analyzed by transcriptomic sequencing.Results: The prognosis of PDAC with high ENO1 expression was poor(P < 0.05). High ENO1 expression was closely associated with histological differentiation and tumor invasion in 84 PDAC cases(P < 0.05). Hypoxia increased ENO1 expression in PDAC and promoted its migration and invasion. Apoptotic cells and the apoptosis marker caspase-3 in the CoCl_(2)-treated ENO1-sh group were significantly elevated(P < 0.05). Transcriptomic sequencing indicated that CoCl_(2)-induced PDAC cells initiated MAPK signaling. Under hypoxic conditions, PDAC cells upregulated ENO1 expression, thereby accelerating ERK phosphorylation and inhibiting apoptosis(P < 0.05). Consistent results were also observed in a PDAC-bearing mouse hindlimb ischemia model.Conclusions: Hypoxia-induced ENO1 expression promotes ERK phosphorylation and inhibits apoptosis, thus leading to PDAC survival and invasion. These results suggest that ENO1 is a potential therapeutic target for PDAC.

Polarized red, green, and blue light emitting diodes fabricated with identical device configuration using rubbed PEDOT:PSS as alignment layer

Polarized red, green, and blue light emitting diodes(LEDs) are successfully fabricated using polyfluorene and its derivatives, namely, poly(9,9-dioctylfluorene)(PFO), poly(9,9-dioctylfluorene-co-benzothiadiazole)(F8BT),and poly(triphenylamine-co-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole-co-benzo[c]thiadiazole-co-9,9-dioctyl-9 Hfluorene)(Red F).Rubbed hole transport layer poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate)(PEDOT:PSS)is employed in the devices as the alignment layer to achieve fully monodomain alignment in all polymer layers.Red F is blended with F8BT to realize the polarized electroluminescence of red light(dichroic ratio ~3.3), despite having no liquid crystallinity itself.Comparing PFO/F8BT blend to F8BT, higher efficiency of polarized emission is found due to the energy transfer.All the polarized LEDs exhibit pronounced dichroism and efficient polarized emission compared to the non-alignment regular devices.

BICC1 drives pancreatic cancer progression by inducing VEGF-independent angiogenesis

VEGF inhibitors are one of the most successful antiangiogenic drugs in the treatment of many solid tumors.Nevertheless,pancreatic adenocarcinoma(PAAD)cells can reinstate tumor angiogenesis via activation of VEGF-independent pathways,thereby conferring resistance to VEGF inhibitors.Bioinformatic analysis showed that BICC1 was one of the top genes involved in the specific angiogenesis process of PAAD.The analysis of our own cohort confirmed that BICC1 was overexpressed in human PAAD tissues and was correlated to increased microvessel density and tumor growth,and worse prognosis.In cells and mice with xenograft tumors,BICC1 facilitated angiogenesis in pancreatic cancer in a VEGF-independent manner.Mechanistically,as an RNA binding protein,BICC1 bounds to the 3’UTR of Lipocalin-2(LCN2)mRNA and post-transcriptionally up-regulated LCN2 expression in PAAD cells.When its level is elevated,LCN2 binds to its receptor 24p3R,which directly phosphorylates JAK2 and activates JAK2/STAT3 signal,leading to increased production of an angiogenic factor CXCL1.Blocking of the BICC1/LCN2 signalling reduced the microvessel density and tumor volume of PAAD cell grafts in mice,and increased the tumor suppressive effect of gemcitabine.In conclusion,BICC1 plays a pivotal role in the process of VEGF-independent angiogenesis in pancreatic cancer,leading to resistance to VEGF inhibitors.BICC1/LCN2 signaling may serve as a promising anti-angiogenic therapeutic target for pancreatic cancer patients.