Hypoxia and dysregulation of microRNAs (miRNAs) have been identified as crucial factors in carcinogenesis. However, the potential mechanisms of HIF-1α and miR-421 in gastric cancer have not been well elucidated. In this study, we found that miR-421 was up-regulated by HIF-1α. Overexpression of miR-421 promoted metastasis, inhibited apoptosis, and induced cisplatin resistance in gastric cancer in vivo and in vitro. E-cadherin and caspase-3 were identified as targets of miR-421. Besides, relative mRNA expression of miR-421 was significantly increased in gastric cancer tumor tissues compared with non-tumor tissues in a cohort of gastric cancer specimens (n=107). The expression of miR-421 was higher in advanced gastric cancers compared with localized ones. Moreover, Kaplan–Meier analysis illustrated that those patients with low levels of miR-421 had a significant longer overall survival (p = 0.006) and time to relapse (p = 0.007). Therefore, miR-421 could serve as an important prognostic marker and a potential molecular target for therapy in gastric cancer.

No abstract

No abstract

Cytokine-induced killer (CIK) cells represent a realistic approach in cancer immunotherapy with confirmed survival benefits in the context of metastatic solid tumors. However, therapeutic effects are limited to a fraction of patients. In this study, immune-resistance elements and ideal combination therapies were explored. Initially, phenotypic analysis was performed to document CD3, CD56, NKG2D, DNAM-1, PD-L1, PD-1, CTLA-4, TIM-3, 2B4, and LAG-3 on CIK cells. Upon engagement of CIK cells with the tumor cells, expression of PD-1 on CIK cells and PD-L1 on both cells were up-regulated. Over-expression of PD-L1 levels on tumor cells via lentiviral transduction inhibited tumoricidal activity of CIK cells, and neutralizing of PD-L1/PD-1 signaling axis could enhance their tumor-killing effect. Conversely, blockade of NKG2D, a major activating receptor of CIK cells, largely caused dysfunction of CIK cells. Functional study showed an increase of NKG2D levels along with PD-L1/PD-1 blockade in the presence of other immune effector molecule secretion. Additionally, combined therapy of CIK infusion and PD-L1/PD-1 blockade caused a delay of in vivo tumor growth and exhibited a survival advantage over untreated mice. These results provide a preclinical proof-of-concept for simultaneous PD-L1/PD-1 pathways blockade along with CIK infusion as a novel immunotherapy for unresectable cancers.

Nonlinear optical imaging with femtosecond (10 ؊15 -second) laser technology was used to evaluate the subsurface tumor progression in control, dysplasia, and cancerous 7,12-dimethylbenz[a]anthracene-treated hamster cheek pouch mucosa tissues. Two-dimensional images of hamster cheek pouch mucosa tissues were obtained by scanning the second harmonic signal at various sagittal and axial positions. The spatial mapping of the second harmonic signals showed depth differentiation between normal, dysplasia, and a more advanced cancerous state. This nonlinear optical method offers a noninvasive in situ imaging tool to the medical community.The medical community is searching for new and noninvasive in situ methods to better characterize the mucosal tissues of the cervix, colon, ear, nose, throat, oral cavity, and esophagus, where disease starts at the epithelial layer a few hundred micrometers beneath the surface. Second harmonic generation (SHG) imaging is a nonlinear optical technique that produces images of subsurface structures, rendering in situ histological information of tissues without surgery. The imageforming signal depends on the morphological symmetry of the molecules and the local intra-and intercellular matrices of the tissue. This symmetry dependence is derived from the secondorder, nonlinear optical susceptibility 2 tensor component that has been used to study phenomena both in the interior region and at surfaces or interfaces in various materials, including biological samples (1-6).SHG tomography can provide information about tissue structure in addition to that offered by other linear optical microscopy techniques, such as optical coherence tomography (OCT) and reflectance confocal microscopy (7,8). Both of these latter methods depend on the reflectance changes caused by local variations in the indices of refraction. Imaging techniques such as ultrasound and MRI with surface coils (100-m in spatial resolution) are limited in their ability to provide submicrometer resolutions that are comparable to linear and nonlinear optical microscopy (9, § ). The application of localized excitation makes it possible to use optical sectioning and image mapping in evaluating tissue in situ. This nonlinear optical technique allows imaging that is not restricted to signals emitted from fluorescent molecules. The illumination needs not correspond to a particular absorption band of a molecule; the wavelength can be selected to optimize excitation and imaging conditions. The SHG signal is proportional to the reflective coefficient and dependent on the reciprocal of quadratic powers of the index of refraction (6). This useful property provides a higher optical contrast for visualizing matrix structures than does reflectance microscopy such as OCT, in which the signal is proportional to the reflective coefficients.In this report, we demonstrate the applicability of the SHG imaging technique for the evaluation of subsurface tumor progression from normal to advanced cancer states. This technology provides a noninvasive h...

No abstract

Colorectal cancer (CRC) remains the third most commonly diagnosed cancer, ranking second among the most common causes of cancer-related mortality. Immune checkpoint therapy has recently been shown to have great potential. However, only some patients respond to immune checkpoint blockade, indicating the unmet need for determining the underlying mechanism of colorectal cancer immunosuppression. In this study, we analyzed The Cancer Genome Atlas (TCGA) datasets and found that high expression of PIPKIγ positively correlated with tumor-associated macrophage infiltration. Further loss-of-function studies revealed that silencing PIPKIγ greatly reduced CCL2 expression at both the mRNA and protein levels, leading to weak chemotaxis of cancer cells to macrophages. Mechanistically, PIPKIγ facilitated PI3K-Akt-mTOR signaling pathway activation to increase STAT3 phosphorylation levels, thus triggering CCL2 transcription to enhance tumor-associated macrophage recruitment. These findings identify the PIPKIγ signaling pathway as a new actor in colorectal cancer immunosuppression and a potential therapeutic target for this common cancer.

Radioresistance is one of the major barriers to improve the survival rate of breast cancer patients. Cyclooxygenase 2 (COX-2) is usually overexpressed in highly invasive and metastatic breast cancer, which may indicate an association with breast cancer radioresistance. The function role of COX-2 was investigated by using a radioresistant breast cancer cell line MDA-MB-231/RR10 and its parental cell line MDA-MB-231 cells before or after COX-2 was silenced by a specific small hairpin RNA (shRNA). The cell proliferation, migration, invasion, colony formation, and apoptosis were measured by CCK-8, scratch-wound, transwell, clone formation assay, and flow cytometry. Protein and mRNA expression were analyzed by Western blot and quantitative reverse transcriptase-polymerase chain reaction. COX-2 is upregulated in MDA-MB-231/RR10 cells compared with in MDA-MB-231 cells, and silencing of COX-2 expression by shRNA in MDA-MB-231/RR10 cells decreases the expression of Bcl-2 and Bcl-XL, but increases the proapoptotic protein BAK, leading to the increased apoptosis following treatment with γ-irradiation in comparison with those in control cells. Silencing of COX-2 also increases the expression of β-catenin and E-cadherin, two anti-invasion proteins, resulting in reduced cell migration and invasion tested by transwell chambers and wound-healing assays. Further study demonstrated that COX-2-induced radioresistance is negatively regulated through the phosphorylation of p38 at Tyr182, and that the phosphorylation of p38 induced by TNF-alpha reduces the expression of Bcl-2, BCL-XL, but increases β-catenin and E-cadherin, leading to the decreased invasiveness of cells. Our data suggest that COX-2, p38, Bcl-2, Bcl-XL, β-catenin, and E-cadherin may be considered as potential therapeutic targets against radioresistant breast cancer.