RAB34 was a progression- and prognosis-associated biomarker in gliomas

E2F1‑mediated RAB34 upregulation accelerates the proliferation and inhibits the cell cycle arrest and apoptosis of acute myeloid leukemia cells

Acute myeloid leukemia (AML) is a malignant disease that is mainly arisen from myeloid stem/progenitor cells. The pathogenesis of AML is complex. Ras-related protein member RAS oncogene GTPases (RAB) 34 protein has been reported to serve an important role in the development of cancer. However, to the best of our knowledge, the role of RAB34 in AML has not been previously reported. The GEPIA database was used to predict the expression levels of RAB34 in patients with AML. Reverse transcription-quantitative PCR and western blotting were used to detect the expression of RAB34 in AML cell lines. Cell transfection with short hairpin (sh)RNAs targeting RAB34 was used to interfere with RAB34 expression. Cell Counting Kit-8 and 5-ethynyl-2'-deoxyuridine staining were used to measure cell proliferation. Flow cytometry was used to investigate cell cycle distribution and apoptosis. Western blotting was used to assess the protein expression levels of RAB34 and E2F transcription factor 1 (E2F1), and cell cycle- and apoptosis-associated proteins, including Bcl-2, Bax, CDK4, CDK8 and cyclin D1. The potential binding between E2F1 and RAB34 was then verified by luciferase reporter and chromatin immunoprecipitation assays. Subsequently, cells were co-transfected with RAB34 shRNA and the E2F1 overexpression plasmid before cell proliferation, cell cycle and apoptosis were analyzed further. The expression of RAB34 was found to be significantly increased in AML cell lines. Knocking down RAB34 expression in AML cells was found to significantly inhibit cell proliferation, induce cell cycle arrest and promote apoptosis. E2F1 activated the transcription of RAB34 and E2F1 elevation reversed the impacts of RAB34 silencing on cell proliferation, cell cycle and apoptosis in AML. Therefore, these findings suggest that E2F1-mediated RAB34 upregulation may accelerate the malignant progression of AML.

MT1-MMP Expression Levels and Catalytic Functions Dictate LDL Receptor-Related Protein-1 Ligand Internalization Capacity in U87 Glioblastoma Cells

Modulations in cell surface receptor ectodomain proteolytic shedding impact on receptor function and cancer biomarker expression. As such, heavily pursued therapeutic avenues have exploited LDL receptor-related protein-1 (LRP-1)-mediated capacity in internalizing Angiopep-2 (An2), a brain-penetrating peptide that allows An2-drug conjugates to cross the blood-brain tumor barrier (BBTB). Given that LRP-1 is proteolytically shed from the cell surface through matrix metalloproteinase (MMP) activity, the balance between MMP expression/function and LRP-1-mediated An2 internalization is unknown. In this study, we found that membrane type-1 (MT1)-MMP expression increased from grade 1 to 4 brain tumors, while that of LRP-1 decreased inversely. MMP pharmacological inhibitors such as Ilomastat, Doxycycline and Actinonin increased in vitro An2 internalization by up to 2.5 fold within a human grade IV-derived U87 glioblastoma cell model. Transient siRNA-mediated MT1-MMP gene silencing resulted in increased basal An2 cell surface binding and intracellular uptake, while recombinant MT1-MMP overexpression reduced both cell surface LRP-1 expression as well as An2 internalization. The addition of Ilomastat to cells overexpressing recombinant MT1-MMP restored LRP-1 expression at the cell surface and An2 uptake to levels comparable to those observed in control cells. Collectively, our data suggest that MT1-MMP expression status dictates An2-mediated internalization processes in part by regulating cell surface LRP-1 functions. Such evidence prompts preclinical evaluations of combined MMP inhibitors/An2-drug conjugate administration to potentially increase the treatment of high-MT1-MMP-expressing brain tumors.

RNA-seq and ChIP-seq Identification of Unique and Overlapping Targets of GLI Transcription Factors in Melanoma Cell Lines

BACKGROUND

Despite significant progress in therapy, melanoma still has a rising incidence worldwide, and novel treatment strategies are needed. Recently, researchers have recognized the involvement of the Hedgehog-GLI (HH-GLI) signaling pathway in melanoma and its consistent crosstalk with the MAPK pathway. In order to further investigate the link between the two pathways and to find new target genes that could be considered for combination therapy, we set out to find transcriptional targets of all three GLI proteins in melanoma.

METHODS

We performed RNA sequencing on three melanoma cell lines (CHL-1, A375, and MEL224) with overexpressed GLI1, GLI2, and GLI3 and combined them with the results of ChIP-sequencing on endogenous GLI1, GLI2, and GLI3 proteins. After combining these results, 21 targets were selected for validation by qPCR.

RESULTS

RNA-seq revealed a total of 808 differentially expressed genes (DEGs) for GLI1, 941 DEGs for GLI2, and 58 DEGs for GLI3. ChIP-seq identified 527 genes that contained GLI1 binding sites in their promoters, 1103 for GLI2 and 553 for GLI3. A total of 15 of these targets were validated in the tested cell lines, 6 of which were detected by both RNA-seq and ChIP-seq.

CONCLUSIONS

Our study provides insight into the unique and overlapping transcriptional output of the GLI proteins in melanoma. We suggest that our findings could provide new potential targets to consider while designing melanoma-targeted therapy.

The Progression Related Gene RAB42 Affects the Prognosis of Glioblastoma Patients

BACKGROUND

Glioblastoma (GBM) represents the most malignant glioma among astrocytomas and is a lethal form of brain cancer. Many RAB genes are involved in different cancers but RAB42 (Ras-associated binding 42) is seldom studied in GBM. Our study aimed to explore the role of RAB42 expression in the development and prognosis of GBM.

METHODS

All GBM patient data were obtained from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) databases. The relevance of RAB42 expression to the clinicopathologic characteristics of GBM patients was analyzed. The overall survival (OS) significance was determined using log-rank. Significantly enriched KEGG pathways were screened using gene set enrichment analysis (GSEA).

RESULTS

High expression of RAB42 was observed in GBM specimens compared with normal samples, which was also verified in cell lines and tissue samples. Elevated RAB42 expression was correlated with higher GBM histological grade. The prognosis of GBM patients with high RAB42 expression was worse than those with lower RAB42. A total of 35 pathways, such as the P53 pathway, were significantly activated in highly RAB42-expressed GBM samples.

CONCLUSIONS

High RAB42 expression is related to the development of GBM, and RAB42 is a probable prognostic marker for GBM.

HSPA6 is Correlated With the Malignant Progression and Immune Microenvironment of Gliomas

Gliomas are primary intracranial space lesions with a high mortality rate. Current treatments for glioma are very limited. Recently, immunotargeted therapy of the glioma microenvironment has been developed. Members of the 70 kDa heat shock protein (HSP70) family are involved in the development of many tumors and immunity. HSPA6 protein belongs to the HSP70 family; However, the biological function of this protein in gliomas has yet to be evaluated. In the present study, a range of analyses, involving protein networks, survival, clinical correlation, and function, revealed that the expression of HSPA6 was negatively correlated with clinical prognosis and closely associated with immunity, invasion, and angiogenesis. Quantitative protein analysis confirmed that HSPA6 was expressed at high levels in patients with glioblastoma. Vitro experiments further verified that HSPA6 enhanced the malignant progression of glioma cells by promoting proliferation, invasion and anti-apoptosis. We also found that HSPA6 was closely correlated with genomic variations and tumor microenvironment. Collectively, we demonstrated that HSPA6 may represent a new therapeutic target to improve the prognosis of patients with gliomas.

Expression of Rab3b in Human Glioma: Influence on Cell Proliferation and Apoptosis

BACKGROUND

Glioma is the most common human central nervous system tumour with a high degree of malignancy. Some Rab GTPases have significant effects on glioma.

OBJECTIVE

This study aimed to investigate the effect of Rab3b (Rab GTPase3b) on human glioma cell proliferation and apoptosis by silencing Rab3b and to initially verify the value of Rab3b expression for the diagnosis and progression in human glioma.

METHODS

Rab3b was silenced by siRNA transfection. Human glioma tissues and normal brain tissues adjacent to glioma were obtained by surgery. Rab3b, P53, Caspase 7, Bax, and Bim mRNA and protein expression levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Cell proliferation was detected by the cell counting kit-8 assay, and the cell cycle and apoptosis were analysed using flow cytometry.

RESULTS

Rab3b mRNA and protein expression in human glioma U251 and U87 cells were significantly downregulated after Rab3b silencing. Rab3b silencing inhibited glioma cell proliferation by promoting cell cycle arrest and induced apoptosis by upregulating the expression of apoptosis-related proteins. Rab3b expression in human glioma (n = 33) was significantly higher than that in normal brain tissues adjacent to glioma (n = 15). In addition, Rab3b expression levels in high-grade gliomas (WHO III-IV, n = 19) were also significantly higher than those in low-grade gliomas (WHO I-II, n = 14).

CONCLUSION

Rab3b expression levels are significantly related to the progression of gliomas. Moreover, Rab3b silencing not only significantly inhibits cell proliferation in gliomas via cell cycle arrest but also promotes cell apoptosis by upregulating the expression levels of apoptosis-related proteins; however these preliminary in vitro results warrant validation on in vivo studies.

Metabolic labeling with an alkyne probe reveals similarities and differences in the prenylomes of several brain-derived cell lines and primary cells

Protein prenylation involves the attachment of one or two isoprenoid group(s) onto cysteine residues positioned near the C-terminus. This modification is essential for many signal transduction processes. In this work, the use of the probe C15AlkOPP for metabolic labeling and identification of prenylated proteins in a variety of cell lines and primary cells is explored. Using a single isoprenoid analogue, 78 prenylated protein groups from the three classes of prenylation substrates were identified including three novel prenylation substrates in a single experiment. Applying this method to three brain-related cell lines including neurons, microglia, and astrocytes showed substantial overlap (25%) in the prenylated proteins identified. In addition, some unique prenylated proteins were identified in each type. Eight proteins were observed exclusively in neurons, five were observed exclusively in astrocytes and three were observed exclusively in microglia, suggesting their unique roles in these cells. Furthermore, inhibition of farnesylation in primary astrocytes revealed the differential responses of farnesylated proteins to an FTI. Importantly, these results provide a list of 19 prenylated proteins common to all the cell lines studied here that can be monitored using the C15AlkOPP probe as well as a number of proteins that were observed in only certain cell lines. Taken together, these results suggest that this chemical proteomic approach should be useful in monitoring the levels and exploring the underlying role(s) of prenylated proteins in various diseases.

OSlgg: An Online Prognostic Biomarker Analysis Tool for Low-Grade Glioma

Glioma is the most frequent primary brain tumor that causes high mortality and morbidity with poor prognosis. There are four grades of gliomas, I to IV, among which grade II and III are low-grade glioma (LGG). Although less aggressive, LGG almost universally progresses to high-grade glioma and eventual causes death if lacking of intervention. Current LGG treatment mainly depends on surgical resection followed by radiotherapy and chemotherapy, but the survival rates of LGG patients are low. Therefore, it is necessary to use prognostic biomarkers to classify patients into subgroups with different risks and guide clinical managements. Using gene expression profiling and long-term follow-up data, we established an Online consensus Survival analysis tool for LGG named OSlgg. OSlgg is comprised of 720 LGG cases from two independent cohorts. To evaluate the prognostic potency of genes, OSlgg employs the Kaplan-Meier plot with hazard ratio and p value to assess the prognostic significance of genes of interest. The reliability of OSlgg was verified by analyzing 86 previously published prognostic biomarkers of LGG. Using OSlgg, we discovered two novel potential prognostic biomarkers (CD302 and FABP5) of LGG, and patients with the elevated expression of either CD302 or FABP5 present the unfavorable survival outcome. These two genes may be novel risk predictors for LGG patients after further validation. OSlgg is public and free to the users at http://bioinfo.henu.edu.cn/LGG/LGGList.jsp.

PVT1 Promotes the Proliferation and Migration of Non-Small Cell Lung Cancer via Regulating miR-148/RAB34 Signal Axis

Objective

It has been verified that long non-coding RNAs (lncRNAs) play critical roles in the development of human cancers. Increasing evidence indicates that lncRNA human plasmacytoma variant translocation1 (PVT1) was dysregulated in non-small cell lung cancer (NSCLC) which is the leading cause of cancer-related death. However, the precise mechanism underlying the effect of PVT1 remains elusive. Our research focused on the correlation of PVT1 to miR-148 and RAB34 in NSCLC.

Methods

The quantitative real-time PCR (qRT-PCR) and western blot assay were used to detect gene and protein expression in NSCLC tissues and cells. CCK8, colony formation, transwell and wound healing assays were performed to evaluate the cell function of NSCLC cells. Dual-luciferase activity assay and RNA pull down assays were performed to verify the interaction between miR-148 and its targets. A xenograft test was conducted to detect the impact of RAB34 on tumor development in vitro.

Results

In NSCLC tissues and cells, PVT1 and RAB34 were up-regulated, and miR-148 was down-regulated. Overexpression of PVT1 was capable of promoting NSCLC cell proliferation and migration which could be reversed by miR-148 restoration or RAB34 knock down. Also, our data firstly determined that the down-regulation of RAB34 had inhibitor effects while the up-regulation of RAB34 had promotive effects on tumor growth in vitro and in vivo.

Conclusion

Those findings indicated that the signal pathway PVT1/miR-148/RAB34 play critical roles in the progression of NSCLC could be proposed in NSCLC as a possible diagnosis or therapeutic targets.

A Humanized Yeast Phenomic Model of Deoxycytidine Kinase to Predict Genetic Buffering of Nucleoside Analog Cytotoxicity

Knowledge about synthetic lethality can be applied to enhance the efficacy of anticancer therapies in individual patients harboring genetic alterations in their cancer that specifically render it vulnerable. We investigated the potential for high-resolution phenomic analysis in yeast to predict such genetic vulnerabilities by systematic, comprehensive, and quantitative assessment of drug–gene interaction for gemcitabine and cytarabine, substrates of deoxycytidine kinase that have similar molecular structures yet distinct antitumor efficacy. Human deoxycytidine kinase (dCK) was conditionally expressed in the Saccharomyces cerevisiae genomic library of knockout and knockdown (YKO/KD) strains, to globally and quantitatively characterize differential drug–gene interaction for gemcitabine and cytarabine. Pathway enrichment analysis revealed that autophagy, histone modification, chromatin remodeling, and apoptosis-related processes influence gemcitabine specifically, while drug–gene interaction specific to cytarabine was less enriched in gene ontology. Processes having influence over both drugs were DNA repair and integrity checkpoints and vesicle transport and fusion. Non-gene ontology (GO)-enriched genes were also informative. Yeast phenomic and cancer cell line pharmacogenomics data were integrated to identify yeast–human homologs with correlated differential gene expression and drug efficacy, thus providing a unique resource to predict whether differential gene expression observed in cancer genetic profiles are causal in tumor-specific responses to cytotoxic agents.

31 gene expression-based signatures serve as indicators of prognosis for patients with glioma

Glioma has one of the highest mortality rates of all cancer types; however, the prognosis cannot be predicted effectively using clinical indicators, due to the biological heterogeneity of the disease. A total of 31 gene expression-based signatures were identified using selected features in The Cancer Genome Atlas cohorts and machine learning methods. The signatures were assayed in the training dataset and were further validated in four completely independent datasets. Association analyses were implemented, and the results indicated that the signature was not significantly associated with age, radiation therapy or primary tumor size. A nomogram for the 1-year overall survival rate of patients with glioma following initial diagnosis was plotted to facilitate the clinical utilization of the signature. Gene Set Enrichment Analysis was performed based on the signature, in order to determine the potential altered pathways. Metabolic pathways were determined to be significantly enriched. In summary, the 31 gene expression-based signatures were effective and robust in predicting the clinical outcome of glioma in 1,016 glioma samples in five independent international cohorts.

Serum ROCK1 mRNA is of great diagnostic value for glioma patients

The study aimed to measure the presence of rho-associated protein kinase 1 (ROCK1) mRNA in serum samples collected from glioma and investigate its diagnostic significance in glioma.The presence of ROCK1 mRNA was examined by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between ROCK1 mRNA and clinical characteristics was analyzed via Chi-square test. The criteria of diagnosis evaluation, including sensitivity, specificity, optimal cutoff point, and area under the curve (AUC) were determined through the receiver operating characteristic (ROC) curve analysis.ROCK1 mRNA was significantly increased in serum samples collected from glioma patients compared to the controls (P <.05). Besides, high ROCK1 mRNA expression was tightly related with Karnofsky Performance Status (KPS) score (P = .024) and World Health Organization (WHO) grade (P = .029). However, there was no association between ROCK1 expression and gender, neurological disorders, family history and cigarette smoking (all, P >.05). In addition, the optimal cutoff point was 3.025, with the sensitivity and specificity of 88.89% and 79.25%, respectively. The AUC was 0.881, indicating that ROCK1 was a diagnostic biomarker for glioma patients (P <.0001, 95% CI = 0.829-0.933).Serum ROCK1 mRNA is significantly up-regulated in glioma cases compared to healthy controls. ROCK1 may be a potential diagnostic biomarker in glioma.

Dysregulation of Macropinocytosis Processes in Glioblastomas May Be Exploited to Increase Intracellular Anti-Cancer Drug Levels: The Example of Temozolomide

Macropinocytosis is a clathrin-independent endocytosis of extracellular fluid that may contribute to cancer aggressiveness through nutrient supply, recycling of plasma membrane and receptors, and exosome internalization. Macropinocytosis may be notably triggered by epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor (PDGFR), two well-known markers for glioblastoma aggressiveness. Therefore, we studied whether the expression of key actors of macropinocytosis is modified in human glioma datasets. Strong deregulation has been evidenced at the mRNA level according to the grade of the tumor, and 38 macropinocytosis-related gene signatures allowed discrimination of the glioblastoma (GBM) samples. Honokiol-induced vacuolization was then compared to vacquinol-1 and MOMIPP, two known macropinocytosis inducers. Despite high phase-contrast morphological similarities, honokiol-induced vacuoles appeared to originate from both endocytosis and ER. Also, acridine orange staining suggested differences in the macropinosomes’ fate: their fusion with lysosomes appeared very limited in 3-(5-methoxy -2-methyl-1H-indol-3-yl)-1-(4-pyridinyl)-2-propen-1-one (MOMIPP)-treated cells. Nevertheless, each of the compounds markedly increased temozolomide uptake by glioma cells, as evidenced by LC-MS. In conclusion, the observed deregulation of macropinocytosis in GBM makes them prone to respond to various compounds affecting their formation and/or intracellular fate. Considering that sustained macropinocytosis may also trigger cell death of both sensitive and resistant GBM cells, we propose to envisage macropinocytosis inducers in combination approaches to obtain dual benefits: increased drug uptake and additive/synergistic effects.

Glioma Cell Secretion: A Driver of Tumor Progression and a Potential Therapeutic Target

Cellular secretion is an important mediator of cancer progression. Secreted molecules in glioma are key components of complex autocrine and paracrine pathways that mediate multiple oncogenic pathologies. In this review, we describe tumor cell secretion in high-grade glioma and highlight potential novel therapeutic opportunities. Cancer Res; 78(21); 6031-9. ©2018 AACR.

Rab34 regulates adhesion, migration, and invasion of breast cancer cells

The small GTPase Rab34 regulates spatial distribution of the lysosomes, secretion, and macropinocytosis. In this study, we found that Rab34 is over-expressed in aggressive breast cancer cells, implying a potential role of Rab34 in breast cancer. Silencing Rab34 by shRNA inhibits cell migration, invasion, and adhesion of breast cancer cells. Rab34 specifically binds to the cytoplasmic tail of integrin β3, and depletion of Rab34 promotes the degradation of integrin β3. Interestingly, EGF induces the translocation of Rab34 to the membrane ruffle, which is greatly enhanced by the expression of Src kinase. Accordingly, Rab34 is tyrosine phosphorylated by Src at Y247 residue. A mutant mimicking phosphorylated form of Rab34 (Rab34Y247D) promotes cell migration and invasion. Importantly, the tyrosine phosphorylation of Rab34 is inhibited in cells in suspension, and increased with the cells re-adhesion. In addition, Rab34Y247D promotes cell adhesion, and enhances integrin β3 endocytosis and recycling. The results uncover a role of Rab34 in migration and invasion of breast cancer cells and its involvement in cancer metastasis, and provide a novel mechanism of tyrosine phosphorylation of Rab34 in regulating cell migration, invasion, and adhesion through modulating the endocytosis, stability, and recycling of integrin β3.

Consequences of Rab GTPase dysfunction in genetic or acquired human diseases

Rab GTPases are important regulators of intracellular membrane trafficking in eukaryotes. Both activating and inactivating mutations in Rab genes have been identified and implicated in human diseases ranging from neurological disorders to cancer. In addition, altered Rab expression is often associated with disease prognosis. As such, the study of diseases associated with Rabs or Rab-interacting proteins has shed light on the important role of intracellular membrane trafficking in disease etiology. In this review, we cover recent advances in the field with an emphasis on cellular mechanisms.

Consequences of Rab GTPase dysfunction in genetic or acquired human diseases

Rab GTPases are important regulators of intracellular membrane trafficking in eukaryotes. Both activating and inactivating mutations in Rab genes have been identified and implicated in human diseases ranging from neurological disorders to cancer. In addition, altered Rab expression is often associated with disease prognosis. As such, the study of diseases associated with Rabs or Rab-interacting proteins has shed light on the important role of intracellular membrane trafficking in disease etiology. In this review, we cover recent advances in the field with an emphasis on cellular mechanisms.

Overexpression of RAB34 correlates with poor prognosis and tumor progression in hepatocellular carcinoma

RAB34, a protein belonging to the RAB family, is involved in protein transport, repositioning of lysosomes and activation of micropinocytosis. However, few studies have reported its function in human epithelial cancers. Immunohistochemistry (IHC) and western blotting were used to detect expression of RAB34 at the tissue and cell levels. Cell Counting Kit-8 (CCK-8), EDU assay and flow cytometry were used for analyzing cell proliferation. Transwell and scratch wound healing assays were used for assessing cell migration ability. Western blotting was used for detecting expression of E-cadherin and N-cadherin. In the present study, we found that both DNA copy and protein level of RAB34 were upregulating in human hepatocellular carcinoma (HCC) tissues when compared with that in adjacent tissues. Analysis of the correlation between RAB34 expression and clinicopathological features showed that patients with overexpression of RAB34 consistently had large tumor size, vessel invasion and poor tumor grade. Furthermore, overall survival analysis showed that patients with upregulated expression of RAB34 were associated with poor prognosis. Moreover, cell function experiments showed that suppression of RAB34 led to a lower proliferation rate and migration ability. In addition, this phenomenon may be attributed to cell cycle phase G1 arrest and mesenchymal-epithelial transition under condition of RAB34 suppression. The present study demonstrated that RAB34 plays an important role in the initiation and progression of HCC. Our results suggest a new therapeutic target for the clinical treatment of HCC.

Targeting Rabs as a novel therapeutic strategy for cancer therapy

Rab GTPases constitute the largest family of small GTPases. Rabs regulate not only membrane trafficking but also cell signaling, growth and survival, and development. Increasingly, Rabs and their effectors are shown to be overexpressed or subject to loss-of-function mutations in a variety of disease settings, including cancer progression. This review provides an overview of dysregulated Rab proteins in cancer, and highlights the signaling and secretory pathways in which they operate, with the aim of identifying potential avenues for therapeutic intervention. Recent progress and perspectives for direct and/or indirect targeting of Rabs are also summarized.

Detection of selection signatures of population-specific genomic regions selected during domestication process in Jinhua pigs

Chinese pigs have been undergoing both natural and artificial selection for thousands of years. Jinhua pigs are of great importance, as they can be a valuable model for exploring the genetic mechanisms linked to meat quality and other traits such as disease resistance, reproduction and production. The purpose of this study was to identify distinctive footprints of selection between Jinhua pigs and other breeds utilizing genome-wide SNP data. Genotyping by genome reducing and sequencing was implemented in order to perform cross-population extended haplotype homozygosity to reveal strong signatures of selection for those economically important traits. This work was performed at a 2% genome level, which comprised 152 006 SNPs genotyped in a total of 517 individuals. Population-specific footprints of selective sweeps were searched for in the genome of Jinhua pigs using six native breeds and three European breeds as reference groups. Several candidate genes associated with meat quality, health and reproduction, such as GH1, CRHR2, TRAF4 and CCK, were found to be overlapping with the significantly positive outliers. Additionally, the results revealed that some genomic regions associated with meat quality, immune response and reproduction in Jinhua pigs have evolved directionally under domestication and subsequent selections. The identified genes and biological pathways in Jinhua pigs showed different selection patterns in comparison with the Chinese and European breeds.

Upregulated long intergenic noncoding RNA KRT18P55 acts as a novel biomarker for the progression of intestinal-type gastric cancer

Background

Long noncoding RNAs (lncRNAs) with dysregulated expression levels have been investigated in numerous types of different cancer. Whether lncRNAs can predict the progression of gastric cancer (GC) still remains largely unclear. The aim of our study was to investigate whether KRT18P55, a novel intergenic lncRNA, can be a predictive biomarker for GC.

Methods

To determine the expression levels of KRT18P55 in GC, we evaluated it in five GC cell lines (SGC-7901, MGC-803, BGC-823, AGS, and HG27) and 97 GC tissue samples in comparison with a normal control by quantitative polymerase chain reaction. In addition, the association with patient clinicopathological characteristics was analyzed to identify the clinical significance of KRT18P55. We also used publicly accessible data from The Cancer Genome Atlas (TCGA) to further verify the expression levels and clinical significance of KRT18P55. Furthermore, a receiver operating characteristic curve was also conducted to evaluate the diagnostic value of KRT18P55 for GC.

Results

A significant upregulation was observed in GC cell lines (P<0.01) and tissue samples (P<0.01). This finding was consistent with the results of 29 pairs of GC tissue samples from TCGA (P<0.01). Additionally, we indicated that the increased expression of KRT18P55 was related to the progression of intestinal type (P=0.032), which was also supported by results of independent GC cohorts from TCGA (P<0.01). However, we did not find significant difference in prognosis between patients with high and low expression of KRT18P55 (P>0.05). Finally, KRT18P55 showed potential diagnostic value for GC with an area under the receiver operating characteristic curve of 0.733 (P<0.01).

Conclusion

Upregulated KRT18P55 was a novel biomarker for the progression of GC, especially for the intestinal type.

Immunohistochemical Markers Distinguishing Cholangiocellular Carcinoma (CCC) from Pancreatic Ductal Adenocarcinoma (PDAC) Discovered by Proteomic Analysis of Microdissected Cells

Cholangiocellular carcinoma (CCC) and pancreatic ductal adenocarcinoma (PDAC) are two highly aggressive cancer types that arise from epithelial cells of the pancreatobiliary system. Owing to their histological and morphological similarity, differential diagnosis between CCC and metastasis of PDAC located in the liver frequently proves an unsolvable issue for pathologists. The detection of biomarkers with high specificity and sensitivity for the differentiation of these tumor types would therefore be a valuable tool. Here, we address this problem by comparing microdissected CCC and PDAC tumor cells from nine and eleven cancer patients, respectively, in a label-free proteomics approach. The novel biomarker candidates were subsequently verified by immunohistochemical staining of 73 CCC, 78 primary, and 18 metastatic PDAC tissue sections. In the proteome analysis, we found 180 proteins with a significantly differential expression between CCC and PDAC cells (p value < 0.05, absolute fold change > 2). Nine candidate proteins were chosen for an immunohistochemical verification out of which three showed very promising results. These were the annexins ANXA1, ANXA10, and ANXA13. For the correct classification of PDAC, ANXA1 showed a sensitivity of 84% and a specificity of 85% and ANXA10 a sensitivity of 90% at a specificity of 66%. ANXA13 was higher abundant in CCC. It presented a sensitivity of 84% at a specificity of 55%. In metastatic PDAC tissue ANXA1 and ANXA10 showed similar staining behavior as in the primary PDAC tumors (13/18 and 17/18 positive, respectively). ANXA13, however, presented positive staining in eight out of eighteen secondary PDAC tumors and was therefore not suitable for the differentiation of these from CCC. We conclude that ANXA1 and ANXA10 are promising biomarker candidates with high diagnostic values for the differential diagnosis of intrahepatic CCC and metastatic liver tumors deriving from PDAC.