Overexpression of RhoGDI2 correlates with the progression and prognosis of pancreatic carcinoma

Proteomic Analysis Identifies Three Reliable Biomarkers of Intestinal Inflammation in the Stools of Patients With Inflammatory Bowel Disease

BACKGROUND

Faecal biomarkers have emerged as important tools in managing of inflammatory bowel disease [IBD], which includes Crohn's disease [CD] and ulcerative colitis [UC].

AIM

To identify new biomarkers of gut inflammation in the stools of IBD patients using a proteomic approach.

METHODS

Proteomic analysis of stools was performed in patients with both active CD and CD in remission and in controls by 2-DIGE and MALDI-TOF/TOF MS. An ELISA was used to confirm results in a second cohort of IBD patients and controls.

RESULTS

2-DIGE analysis detected 70 spots in the stools of patients with active CD or patients in remission CD and in controls. MALDI-TOF/TOF MS analysis identified 21 proteins with Chymotrypsin C, Gelsolin and Rho GDP-dissociation inhibitor 2 [RhoGDI2] best correlating with the levels of intestinal inflammation. Results were confirmed in a second cohort of IBD patients and controls [57 CD, 60 UC, 31 controls]. The identified faecal markers significantly correlated with the severity of intestinal inflammation in IBD patients [SES-CD in CD, Mayo endoscopic subscore in UC] [CD; Chymotrypsin-C: r = 0.64, p < 0.001; Gelsolin: r = 0.82, p < 0.001; RhoGDI2: r = 0.64, p < 0.001; UC; Chymotrypsin-C: r = 0.76, p < 0.001; Gelsolin: r = 0.75, p < 0.001; RhoGDI2: r = 0.63, p < 0.001]. Moreover, ROC analysis showed that Gelsolin [p < 0.0002] and RhoGDI2 [p < 0.0001] in CD, and RhoGDI2 [p = 0.0004] in UC, have higher sensitivity and specificity than faecal calprotectin in discriminating between patients and controls.

CONCLUSIONS

We show for the first time that 2-DIGE is a reliable method to detect proteins in human stools. Three novel faecal biomarkers of gut inflammation have been identified that display good specificity and sensitivity for identifying IBD and significantly correlate with IBD severity.

Establishment of a five-enzalutamide-resistance-related-gene-based classifier for recurrence-free survival predicting of prostate cancer

To identify prostate cancer (PCa) patients with a high risk of recurrence is critical before delivering adjuvant treatment. We developed a classifier based on the Enzalutamide treatment resistance‐related genes to assist the currently available staging system in predicting the recurrence‐free survival (RFS) prognosis of PCa patients. We overlapped the DEGs from two datasets to obtain a more convincing Enzalutamide‐resistance‐related‐gene (ERRG) cluster. The five‐ERRG‐based classifier obtained good predictive values in both the training and validation cohorts. The classifier precisely predicted RFS of patients in four cohorts, independent of patient age, pathological tumour stage, Gleason score and PSA levels. The classifier and the clinicopathological factors were combined to construct a nomogram, which had an increased predictive accuracy than that of each variable alone. Besides, we also compared the differences between high‐ and low‐risk subgroups and found their differences were enriched in cancer progression‐related pathways. The five‐ERRG‐based classifier is a practical and reliable predictor, which adds value to the existing staging system for predicting the RFS prognosis of PCa after radical prostatectomy, enabling physicians to make more informed treatment decisions concerning adjuvant therapy.

Novel Diagnostic Biomarkers for High-Grade Serous Ovarian Cancer Uncovered by Data-Independent Acquisition Mass Spectrometry

High-grade serous ovarian cancer (HGSOC) represents the major histological type of ovarian cancer, and the lack of effective screening tools and early detection methods significantly contributes to the poor prognosis of HGSOC. Currently, there are no reliable diagnostic biomarkers for HGSOC. In this study, we performed liquid chromatography data-independent acquisition tandem mass spectrometry (MS) on depleted serum samples from 26 HGSOC cases and 24 healthy controls (HCs) to discover potential HGSOC diagnostic biomarkers. A total of 1,847 proteins were identified across all samples, among which 116 proteins showed differential expressions between HGSOC patients and HCs. Network modeling showed activations of coagulation and complement cascades, platelet activation and aggregation, neutrophil extracellular trap formation, toll-like receptor 4, insulin-like growth factor, and transforming growth factor β signaling, as well as suppression of lipoprotein assembly and Fc gamma receptor activation in HGSOC. Based on the network model, we prioritized 28 biomarker candidates and validated 18 of them using targeted MS assays in an independent cohort. Predictive modeling showed a sensitivity of 1 and a specificity of 0.91 in the validation cohort. Finally, in vitro functional assays on four potential biomarkers (FGA, VWF, ARHGDIB, and SERPINF2) suggested that they may play an important role in cancer cell proliferation and migration in HGSOC. All raw data were deposited in PRIDE (PXD033169).

RhoGDI2 induced malignant phenotypes of pancreatic cancer cells via regulating Snail expression

BACKGROUND

Rho GDP dissociation inhibitor 2 (RhoGDI2) has been shown to contribute to the aggressive phenotypes of human cancers, such as tumor metastasis and chemoresistance.

OBJECTIVE

This study aimed to assess the effects of RhoGDI2 on tumor progression and chemoresistance in pancreatic cancer cells.

METHODS

The expression of RhoGDI2 in pancreatic cancer cells was detected by Western blot analysis. Gain-of-function and loss-of-function approaches were done to examine the malignant phenotypes of the RhoGDI2-expressing or RhoGDI2-depleting cells. The correlation between RhoGDI2 and Snail was also analyzed.

RESULTS

Differential expression of RhoGDI2 protein in pancreatic cancer cell lines was identified. Gain-of-function and loss-of-function experiments showed that RhoGDI2 induced the malignant phenotypes of pancreatic cancer cells, including proliferation, migration, invasion, and gemcitabine (GEM) chemoresistance. The upregulation of RhoGDI2 stimulated the expression of Snail, resulting in the altered expression of epithelial marker E-cadherin and mesenchymal marker Vimentin, which were characteristics of the tumorigenic activity of epithelial-mesenchymal transition. The expression of RhoGDI2 and Snail was upregulated in clinical tumor samples, and higher expression of RhoGDI2 or Snail was significantly associated with poor patient survival in pancreatic ductal adenocarcinoma (PDAC).

CONCLUSION

The findings indicated that RhoGDI2 promoted GEM resistance and tumor progression in pancreatic cancer and that RhoGDI2 might be a potential therapeutic target in patients with PDAC.

Risk subtyping and prognostic assessment of prostate cancer based on consensus genes

Prostate cancer (PCa) is the most frequent malignancy in male urogenital system around worldwide. We performed molecular subtyping and prognostic assessment based on consensus genes in patients with PCa. Five cohorts containing 1,046 PCa patients with RNA expression profiles and recorded clinical follow-up information were included. Univariate, multivariate Cox regression analysis and least absolute shrinkage and selection operator (LASSO) Cox regression were used to select prognostic genes and establish the signature. Immunohistochemistry staining, cell proliferation, migration and invasion assays were used to assess the biological functions of key genes. Thirty-nine intersecting consensus prognostic genes from five independent cohorts were identified. Subsequently, an eleven-consensus-gene classifier was established. In addition, multivariate Cox regression analyses showed that the classifier served as an independent indicator of recurrence-free survival in three of the five cohorts. Combined receiver operating characteristic (ROC) analysis achieved synthesized effects by combining the classifier with clinicopathological features in four of five cohorts. SRD5A2 inhibits cell proliferation, while ITGA11 promotes cell migration and invasion, possibly through the PI3K/AKT signaling pathway. To conclude, we established and validated an eleven-consensus-gene classifier, which may add prognostic value to the currently available staging system.

By analysis of gene expression profiles of prostate cancer patients from multiple platforms, an eleven-consensus-gene classifier is constructed to provide a robust tool for the prediction of recurrence-free survival.

Radioproteomics in patients with ovarian cancer

Radioproteomics is the integration of proteomics, the systematic study of the protein expression of an organism, with radiomics, the extraction and analysis of large numbers of quantitative features from medical images. This article examines this developing field, and it's application in high grade serous ovarian carcinoma. Seminal proteomic studies in the area of ovarian cancer, such as the PROVAR and CPTA studies are discussed, along side recent research, such as that highlighting the central role of methyltransferase nicotinamide N-methyltransferase as the metabolic regulation of cancer progression in the tumour stroma. Finally, this article considers a novel, hypothesis generating approach to integrate CT-based qualitative and radiomic features with proteomic analysis, and the future direction of the field. Combined advances in radiomic, proteomic and genomic analysis has the potential to signal the age of true precision medicine, where treatment is centered specifically on the molecular profile of the tumour, rather than based on empirical knowledge, thus altering the course of a disease that has the highest mortality of all cancers of the female reproductive system.

2-O-Octadecylascorbic acid represses RhoGDIβ expression and ameliorates DNA damage-induced abnormal spindle orientations

The appropriate regulation of spindle orientation maintains proper tissue homeostasis and avoids aberrant tissue repair or regeneration. Spindle misorientation due to imbalance or improper functioning leads to a loss of tissue integrity and aberrant growth, such as tissue loss or overgrowth. Pharmacological manipulation to prevent spindle misorientation will enable a better understanding of how spindle orientation is involved in physiological and pathological conditions and will provide therapeutic possibilities to treat patients associated with abnormal tissue function caused by spindle misorientation. N-terminal-deleted Rho guanine nucleotide dissociation inhibitor β (RhoGDIβ/RhoGDI2/LyGDI) produced by caspase-3 activation perturbs spindle orientation in surviving cells following exposure to either ionizing radiation or UVC. Thus, presumably, RhoGDIβ cleaved by caspase-3 activation acts as a determinant of radiation-induced spindle misorientation that promote aberrant tissue repair due to deregulation of directional organization of cell population and therefore becomes a potential target of drugs to prevent such response. The objective of this study was to screen and identify chemicals that suppress RhoGDIβ expression. We focused our attention on ascorbic acid (AA) derivatives because of their impact on the maintenance of skin tissue homeostasis. Here, we screened for AA derivatives that suppress RhoGDIβ expression in HeLa cells and identified a lipophilic derivative, 2-O-octadecylascorbic acid (2-OctadecylAA), as a novel RhoGDIβ inhibitor that ameliorated ionizing radiation-induced abnormal spindle orientations. Among all examined AA derivatives, which were also antioxidative, the inhibition activity was specific to 2-OctadecylAA. Therefore, this activity was not due to simple antioxidant properties. 2-OctadecylAA was previously shown to prevent hepatocellular carcinoma development. Our findings suggest that the anticarcinogenic effects of 2-OctadecylAA are partly due to RhoGDIβ inhibition mechanisms by which spindle orientation perturbations are attenuated. Thus, the molecular targeting features of RhoGDIβ warrant its further development for the treatment or control of spindle orientation abnormalities that affect epithelial homeostasis.

Systematic investigation of biomarker-like role of ARHGDIB in breast cancer

BACKGROUND

ARHGDIB, a Rho GDP dissociation inhibitor protein, has been reported playing critical roles in regulation of multiple biological responses. However, whether ARHGDIB serves as a valuable biomarker in cancer is little known so far, especially in breast cancer.

OBJECTIVE

In this study, we aimed to investigate the importance of ARHGDIB in breast cancer, including but not limited to biomarker-like role, as well as potential mechanisms.

METHODS

Total 100 breast cancer samples and 100 benign breast disease samples were enrolled and underwent detailed pathological assessment and IHC analysis. Human breast cancer cell lines and epithelial cell line were subjected to siRNA-mediated knock-down, RT-qPCR, western blot, MTT staining, cell cycle assay, transwell analysis respectively.

RESULTS

We observed the expression of ARHGDIB is significantly higher in human breast cancer tissues compared with the benign tissues. ARHGDIB expression was positively correlated with tumor size, lymph node metastasis and TNM stage in breast cancer patients. Moreover, ARHGDIB depletion decreased proliferation, migration and invasion of breast cancer cells. Furthermore, we found ARHGDIB mediated epithelial-mesenchymal transition, and MMP2 is the key downstream effector of ARHGDIB.

CONCLUSIONS

Hence, our results suggested the significance and predictive role of ARHGDIB in breast cancer. High expression of ARHGDIB indicated the poor prognosis for breast cancer patients.

Identification of a Blood-Based Protein Biomarker Panel for Lung Cancer Detection

Lung cancer is the deadliest cancer worldwide, mainly due to its advanced stage at the time of diagnosis. A non-invasive method for its early detection remains mandatory to improve patients’ survival. Plasma levels of 351 proteins were quantified by Liquid Chromatography-Parallel Reaction Monitoring (LC-PRM)-based mass spectrometry in 128 lung cancer patients and 93 healthy donors. Bootstrap sampling and least absolute shrinkage and selection operator (LASSO) penalization were used to find the best protein combination for outcome prediction. The PanelomiX platform was used to select the optimal biomarker thresholds. The panel was validated in 48 patients and 49 healthy volunteers. A 6-protein panel clearly distinguished lung cancer from healthy individuals. The panel displayed excellent performance: area under the receiver operating characteristic curve (AUC) = 0.999, positive predictive value (PPV) = 0.992, negative predictive value (NPV) = 0.989, specificity = 0.989 and sensitivity = 0.992. The panel detected lung cancer independently of the disease stage. The 6-protein panel and other sub-combinations displayed excellent results in the validation dataset. In conclusion, we identified a blood-based 6-protein panel as a diagnostic tool in lung cancer. Used as a routine test for high- and average-risk individuals, it may complement currently adopted techniques in lung cancer screening.

RhoGDIβ affects HeLa cell spindle orientation following UVC irradiation

The molecular signals that regulate mitotic spindle orientation to determine the proper division axis play a critical role in the development and maintenance of tissue homeostasis. However, deregulation of signaling events can result in spindle misorientation, which in turn can trigger developmental defects and cancer progression. Little is known about the cellular signaling pathway involved in the misorientation of proliferating cells that evade apoptosis after DNA damage. In this study, we found that perturbations to spindle orientation were induced in ultraviolet C (UVC)-irradiated surviving cells. N-terminal truncated Rho GDP-dissociation inhibitor β (RhoGDIβ), which is produced by UVC irradiation, distorted the spindle orientation of HeLa cells cultured on Matrigel. The short hairpin RNA-mediated knockdown of RhoGDIβ significantly attenuated UVC-induced misorientation. Subsequent expression of wild-type RhoGDIβ, but not a noncleavable mutant, RhoGDIβ (D19A), again led to a relative increase in spindle misorientation in response to UVC. Our findings revealed that RhoGDIβ impacts spindle orientation in response to DNA damage.

CD44s is a crucial ATG7 downstream regulator for stem-like property, invasion, and lung metastasis of human bladder cancer (BC) cells

Over half a million US residents are suffering with bladder cancer (BC), which costs a total $4 billion in treatment annually. Although recent studies report that autophagy-related gene 7 (ATG7) is overexpressed in BCs, the regulatory effects of ATG7 on cancer stem-like phenotypes and invasion have not been explored yet. Current studies demonstrated that the deficiency of ATG7 by its shRNA dramatically reduced sphere formation and invasion in vitro, as well as lung metastasis in vivo in human invasive BC cells. Further studies indicated that the knockdown of ATG7 attenuated the expression of CD44 standard (CD44s), while ectopic introduction of CD44s, was capable of completely restoring sphere formation, invasion, and lung metastasis in T24T(shATG7) cells. Mechanistic studies revealed that ATG7 overexpression stabilized CD44s proteins accompanied with upregulating USP28 proteins. Upregulated USP28 was able to bind to CD44s and remove the ubiquitin group from CD44s' protein, resulting in the stabilization of CD44s protein. Moreover, ATG7 inhibition stabilized AUF1 protein and thereby reduced tet1 mRNA stability and expression, which was able to demethylate usp28 promoter, reduced USP28 expression, finally promoting CD44s degradation. In addition, CD44s was defined to inhibit degradation of RhoGDIβ, which in turn promotes BC invasion. Our results demonstrate that CD44s is a key ATG7 downstream regulator of the sphere formation, invasion, and lung metastasis of BCs, providing significant insight into understanding the BC invasions, metastasis, and stem-like properties.

Interferon Gamma Inhibits CXCL8-Induced Proliferation and Migration of Pancreatic Cancer BxPC-3 Cell Line via a RhoGDI2/Rac1/NF-κB Signaling Pathway

Interferon gamma (IFN-γ) is a dimeric soluble cytokine and the only type II interferon. Accumulated evidence suggests that IFN-γ inhibits tumor progression. This study investigated the effects of IFN-γ on the proliferation and migration of pancreatic cancer (PC) cells and the underlying mechanism. IFN-γ treatment decreased the expression and secretion of CXCL8 in BxPC-3 PC cells, suppressed the proliferation and migration of these cells, and enhanced their apoptosis, as determined by increased levels of cleaved Caspase-8 and Bax together with reduced expression of Bcl-2. These effects were abolished by overexpression of CXCL8. Moreover, IFN-γ treatment downregulated RhoGDI2 expression. Depletion of RhoGDI2 and Rac1 by using small interfering RNAs and inhibition of NF-κB by BMS-345541 (an IκB kinase [IKK] inhibitor) suppressed expression of CXCL8. Our results indicate that IFN-γ inhibits the proliferation and migration of PC cells by suppressing CXCL8 expression via a RhoGDI2/Rac1/NF-κB signaling pathway.

RhoGDIβ promotes Sp1/MMP-2 expression and bladder cancer invasion through perturbing miR-200c-targeted JNK2 protein translation

Our most recent studies demonstrate that RhoGDIβ is able to promote human bladder cancer (BC) invasion and metastasis in an X‐link inhibitor of apoptosis protein‐dependent fashion accompanied by increased levels of matrix metalloproteinase (MMP)‐2 protein expression. We also found that RhoGDIβ and MMP‐2 protein expressions are consistently upregulated in both invasive BC tissues and cell lines. In the present study, we show that knockdown of RhoGDIβ inhibited MMP‐2 protein expression accompanied by a reduction of invasion in human BC cells, whereas ectopic expression of RhoGDIβ upregulated MMP‐2 protein expression and promoted invasion as well. The mechanistic studies indicated that MMP‐2 was upregulated by RhoGDIβ at the transcriptional level by increased specific binding of the transcription factor Sp1 to the mmp‐2 promoter region. Further investigation revealed that RhoGDIβ overexpression led to downregulation of miR‐200c, whereas miR‐200c was able directly to target 3′‐UTR of jnk2mRNA and attenuated JNK2 protein translation, which resulted in attenuation of Sp1mRNA and protein expression in turn, inhibiting Sp1‐dependent mmp‐2 transcription. Collectively, our studies demonstrate that RhoGDIβ overexpression inhibits miR‐200c abundance, which consequently results in increases of JNK2 protein translation, Sp1 expression, mmp‐2 transcription, and BC invasion. These findings, together with our previous results showing X‐link inhibitor of apoptosis protein mediating mRNA stabilization of both RhoGDIβ and mmp‐2, reveal the nature of the MMP‐2 regulatory network, which leads to MMP‐2 overexpression and BC invasion.

Integrated Proteogenomic Characterization of Human High-Grade Serous Ovarian Cancer

To provide a detailed analysis of the molecular components and underlying mechanisms associated with ovarian cancer, we performed a comprehensive mass-spectrometry-based proteomic characterization of 174 ovarian tumors previously analyzed by The Cancer Genome Atlas (TCGA), of which 169 were high-grade serous carcinomas (HGSCs). Integrating our proteomic measurements with the genomic data yielded a number of insights into disease, such as how different copy-number alternations influence the proteome, the proteins associated with chromosomal instability, the sets of signaling pathways that diverse genome rearrangements converge on, and the ones most associated with short overall survival. Specific protein acetylations associated with homologous recombination deficiency suggest a potential means for stratifying patients for therapy. In addition to providing a valuable resource, these findings provide a view of how the somatic genome drives the cancer proteome and associations between protein and post-translational modification levels and clinical outcomes in HGSC. VIDEO ABSTRACT.