The expression of acylphosphatase is associated with the metastatic phenotype in human colorectal tumors

Clinical Significance of Acylphosphatase 1 Expression in Combined HCC-iCCA, HCC, and iCCA

BACKGROUND

Combined hepatocellular and cholangiocarcinoma is a rare primary liver cancer with histological features of both hepatocellular carcinoma and intrahepatic cholangiocarcinoma. Little is known about the prognostic features and molecular mechanism of cHCC-iCCA. Acylphosphatase 1 is a cytosolic enzyme that produces acetic acid from acetyl phosphate and plays an important role in cancer progression.

AIMS

We evaluated the clinical significance of ACYP1 expression in cHCC-iCCA, HCC, and iCCA.

METHODS

ACYP1 immunohistochemistry was performed in 39 cases diagnosed with cHCC-iCCA. The prognosis was evaluated in three different cohorts (cHCC-iCCA, HCC, and iCCA). The relationships between ACYP1 expression and cell viability, migration, invasiveness, and apoptosis were examined using siRNA methods in vitro. In vivo subcutaneous tumor volumes and cell apoptosis were evaluated after downregulation of ACYP1 expression.

RESULTS

Almost half of the patients with cHCC-iCCA were diagnosed with high ACYP1 expression. In all three cohorts, the cases with high ACYP1 expression had significantly lower overall survival, and high ACYP1 expression was identified as an independent prognostic factor. Downregulation of ACYP1 reduced the proliferative capacity, migration, and invasiveness of both HCC and iCCA cells. Moreover, knockdown of ACYP1 increased the ratio of apoptotic cells and decreased the expression of anti-apoptosis proteins. In vivo tumor growth was significantly inhibited by the transfection of ACYP1 siRNA, and the number of apoptotic cells increased.

CONCLUSION

High ACYP1 expression could influence the prognosis of cHCC-iCCA, HCC, and iCCA patients. In vitro ACYP1 expression influences the tumor growth and cell viability in both HCC and iCCA by regulating anti-apoptosis proteins.

ACYP1 Is a Pancancer Prognostic Indicator and Affects the Immune Microenvironment in LIHC

Background

ACYP1 plays important physiological and metabolic roles in glycolysis and membrane ion pump activity by catalyzing acyl phosphate hydrolysis. ACYP1 is related to tumorigenesis and progression and poor prognosis in gastrointestinal cancer. However, its pancancer roles and mechanisms are unclear. Our study aimed to understand the ACYP1 expression signature and prognostic value across cancers and investigate immune infiltration patterns in liver hepatocellular carcinoma (LIHC) and verify them in LIHC samples.

Methods

Transcriptional expression profiles of ACYP1 across cancers were analyzed using Oncomine and TIMER. The prognostic value of ACYP1 was assessed across PrognoScan, Kaplan—Meier Plotter, and GEPIA. Significant pathways associated with ACYP1 in LIHC were obtained via Gene Set Enrichment Analysis. The correlation between ACYP1 expression and immune infiltration in LIHC was investigated using TIMER. We validated ACYP1 expression, prognostic value, and association with immune cells in tumor tissues by immunohistochemistry and flow cytometry.

Results

ACYP1 was overexpressed across cancers. High expression of ACYP1 correlated with a poor prognosis in most tumor types, especially in LIHC. ACYP1 was significantly implicated in immune and metabolic related pathways. High ACYP1 expression showed significant correlations with the abundances of Th2 cells, Tregs, macrophages, dendritic cells, and myeloid-derived suppressor cells in LIHC. LIHC patients with high ACYP1 expression showed significantly shorter overall survival and relapse-free survival rates concomitant with increased infiltration of CD4+ T cells. Mouse subcutaneous tumors with ACYP1 overexpression exhibited significantly accelerated tumor progression with increased aggregation of CD4+ T cells.

Conclusion

Overall, ACYP1 may serve as a vital prognostic biomarker and play an immunoregulatory role in LIHC.

ACYP2 contributes to malignant progression of glioma through promoting Ca2+ efflux and subsequently activating c-Myc and STAT3 signals

Background

Acylphosphatase 2 (ACYP2) is involved in cell differentiation, energy metabolism and hydrolysis of intracellular ion pump. It has been reported as a negative regulator in leukemia and a positive regulator in colon cancer, respectively. However, its biological role in glioma remains totally unclear.

Methods

We performed quantitative RT-PCR (qRT-PCR), immunohistochemistry (IHC) and western blot assays to evaluate ACYP2 expression. The functions of ACYP2 in glioma cells were determined by a series of in vitro and in vivo experiments, including cell proliferation, colony formation, cell cycle, apoptosis, migration, invasion and nude mouse tumorigenicity assays. In addition, western blot and co-immunoprecipitation (Co-IP) assays were used to identify its downstream targets.

Results

Knocking down ACYP2 in glioma cells significantly inhibited cell proliferation, colony formation, migration, invasion and tumorigenic potential in nude mice, and induced cell cycle arrest and apoptosis. Conversely, ectopic expression of ACYP2 in glioma cells dramatically promoted malignant phenotypes of glioma cells. Mechanistically, ACYP2 promoted malignant progression of glioma cells through regulating intracellular Ca²⁺ homeostasis via its interaction with PMCA4, thereby activating c-Myc and PTP1B/STAT3 signals. This could be effectively reversed by Ca²⁺ chelator BAPTA-AM or calpain inhibitor calpeptin.

Conclusions

Our data demonstrate that ACYP2 functions as an oncogene in glioma through activating c-Myc and STAT3 signals via the regulation of intracellular Ca²⁺ homeostasis, and indicate that ACYP2 may be a potential therapeutic target and prognostic biomarker in gliomas.

Association between ACYP2 polymorphisms and the risk of renal cell cancer

Background

Kidney cancer is the predominant form of malignancy of the kidney and accounts for approximately 3%–4% of all cancers. Renal cell cancer (RCC) represents more than 85% of kidney cancer. It has been reported that genetic factors may predispose individuals to RCC. This study evaluated the association between Acylphosphatase 2 (ACYP2) gene polymorphisms and RCC risk in the Han Chinese population.

Methods

Twelve single‐nucleotide polymorphisms (SNPs) in ACYP2 were genotyped using the Agena MassARRAY platform from 293 RCC patients and 495 controls. The Chi‐squared test, genetic models, haplotype, and stratification analyses were used to evaluate the association between SNPs and the risk of RCC. The relative risk was estimated using the odds ratio (OR) and 95% confidence interval (CI).

Results

We observed that the rs6713088 allele G (OR = 1.26, 95% CI: 1.03–1.53, p = .023) and rs843711 allele T (OR = 1.29, 95% CI: 1.06–1.57, p = .010) were associated with increased RCC risk. Genetic model analyses found that rs843711 was significantly associated with an increased RCC risk under the recessive model and log‐additive model after adjusting for age and gender. Haplotype analysis showed that the haplotype “TTCTCGCC” (OR = 0.67, 95% CI: 0.48–0.94, p = .021) was associated with a decreased risk of RCC in the Han Chinese population. Stratification analysis also found that rs6713088 and rs843711 were significantly associated with increased RCC risk.

Conclusion

In summary, the results suggested that ACYP2 polymorphisms could be used as a genetic marker for RCC. Additional functional and association studies are required to validate our results.

Genetic variants in the acylphosphatase 2 gene and the risk of breast cancer in a Han Chinese population

We performed a case-control study to investigate the associations between seven single nucleotide polymorphisms (SNPs) in the acylphosphatase 2 (ACYP2) gene and breast cancer (BC) risk in a Han Chinese population. There were 183 BC cases and 195 healthy controls included in the study. The SNPs were genotyped using the Sequenom MassARRAY platform. Logistic regression (adjusted for age group, body mass index [BMI], and menopause status), was used to evaluate the associations between the various genotypes and BC risk. Statistical analysis revealed that rs12621038 was associated with a decreased risk of BC in the allele (T vs. C: odds ratio [OR] = 0.71, 95% confidence interval [95% CI] = 0.52–0.94; p = 0.016), homozygous (TT vs. CC: OR = 0.47, 95% CI = 0.24–0.85; p = 0.014), dominant (OR = 0.62; 95% CI = 0.40−0.96; p = 0.032), and additive (OR = 0.68; 95% CI = 0.50–0.92; p = 0.012) models. In addition, we found that rs1682111 and rs17045754 were associated with the risk of BC and correlated with recurrence, and that rs6713088 correlated with tumor size. In sum, our findings reveal significant associations between SNPs in the ACYP2 gene and BC risk in a Han Chinese population.

Leukocyte telomere length-related genetic variants in ACYP2 contribute to the risk of esophageal carcinoma in Chinese Han population

BACKGROUND

Short leukocyte telomere length has been associated with significantly increased risk of esophageal carcinoma. A previous genome-wide association study demonstrated that ACYP2 was associated with leukocyte telomere length. However, the role of ACYP2 genetic variants on esophageal carcinoma susceptibility is still unknown. Therefore, we investigated whether ACYP2 polymorphisms have impact on the risk of esophageal carcinoma in Chinese.

MATERIALS AND METHODS

We conducted a case-control study among 386 cases and 495 healthy controls from northwest China. 14 SNPs in ACYP2 were selected and genotyped using Sequenom MassARRAY technology. Odds ratios (OR) and 95% confidence intervals (CIs) were calculated by unconditional logistic regression adjusting for age and gender.

RESULTS

We found that 1.34-fold increased risk of esophageal carcinoma is associated with the rs11125529 A allele compared with the rs11125529 C allele (OR=1.29, 95%CI: 1.02-1.62, p=0.030) under the additive model, after adjusted by age and gender. We also found rs11896604 and rs17045754 loci increased the esophageal carcinoma risk under the additive model (rs11896604: OR=1.34, 95%CI: 1.03-1.76, p=0.032; rs17045754: OR=1.36, 95%CI: 1.03-1.80, p=0.028). One main linkage block was observed across the locus. This block was comprised of seven closely linked SNPs: rs1682111, rs843752, rs10439478, rs843645, rs11125529, rs843711 and rs11896604. The haplotype analysis detected that haplotype "TTCTATG" increased the risk of esophageal carcinoma (OR=1.38, 95%CI: 1.04-1.82, p=0.025).

CONCLUSION

In conclusion, ACYP2 gene may be associated with an increased risk of esophageal carcinoma in Chinese Han populations. Future studies to address the biological function of this polymorphism in the development of esophageal carcinoma are warranted.

The genome-wide expression profile of 1,2,3,4,6-penta-O-galloyl-β-D-glucose-treated MDA-MB-231 breast cancer cells: molecular target on cancer metabolism

1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG), a polyphenolic compound isolated from Rhus chinensis Mill. PGG has been known to have anti-tumor, anti-angiogenic and anti-diabetic activities. The present study revealed another underlying molecular target of PGG in MDA-MB-231 breast cancer cells by using Illumina Human Ref-8 expression BeadChip assay. Through the Beadstudio v3 micro assay program to compare the identified genes expressed in PGG-treated MDA-MB-231 cells with untreated control, we found several unique genes that are closely associated with pyruvate metabolism, glycolysis/gluconeogenesis and tyrosine metabolism, including PC, ACSS2, ACACA, ACYP2, ALDH3B1, FBP1, PRMT2 and COMT. Consistent with microarray data, real-time RT-PCR confirmed the significant down-regulation of these genes at mRNA level in PGG-treated MDA-MB-231 cells. Our findings suggest the potential of PGG as anticancer agent for breast cancer cells by targeting cancer metabolism genes.

A 25-signal proteomic signature and outcome for patients with resected non-small-cell lung cancer

BACKGROUND

Among patients with non-small-cell lung cancer (NSCLC), those with poor prognosis cannot be distinguished from those with good prognosis.

METHODS

Matrix-assisted laser desorption-ionization mass spectrometry was used to analyze protein profiles of 174 specimens from NSCLC tumors and 27 specimens from normal lung tissue and to derive a prognosis-associated proteomic signature. Frozen resected tissue specimens were randomly divided into a training set (116 NSCLC and 20 normal lung specimens) and an independent, blinded validation set (58 NSCLC and seven normal lung specimens). Mass spectrometry signals from training set specimens that were differentially associated with specimens from patients with a high risk of recurrence (i.e., who died within 5 years of surgical treatment because of relapse) compared with those from patients with a low risk of recurrence (i.e., alive with no symptoms of relapse after a median follow-up of 89 months) were selected by use of the Fisher's exact test, the Kruskal-Wallis test, and the significance analysis of microarray test. These signals were used to build an individualized, weighted voting-based prognostic signature. The signature was then validated in the independent dataset. Survival was assessed by multivariable Cox regression analysis. Proteins corresponding to individual signals were identified by ion-trap mass spectrometry coupled with high-performance liquid chromatography. All statistical tests were two-sided.

RESULTS

From 2630 mass spectrometry signals from specimens in the training cohort, we derived a signature of 25 signals that was associated with both relapse-free survival and overall survival. Among stage I NSCLC patients in the validation set, the signature was statistically significantly associated with both overall survival (hazard ratio [HR] of death for patients in the high-risk group compared with those in the low-risk group = 61.1, 95% confidence interval [CI] = 8.9 to 419.2, P<.001) and relapse-free survival (HR of relapse = 11.7, 95% CI = 3.1 to 44.8, P<.001). Proteins corresponding to signals in the signature were identified that had various cellular functions, including ribosomal protein L26-like 1, acylphosphatase, and phosphoprotein enriched in astrocytes 15.

CONCLUSIONS

We defined a mass spectrometry signature that was associated with survival among NSCLC patients and appeared to distinguish those with poor prognosis from those with good prognosis.

Upstream binding factor up-regulated in hepatocellular carcinoma is related to the survival and cisplatin-sensitivity of cancer cells

Upstream binding factor (UBF) is an RNA polymerase I-specific transcription factor. By representational difference analysis, Northern blot, and cDNA array analysis, up-regulation of UBF was detected in 12 of 17 clinical hepatocellular carcinoma samples comparing to the paired normal liver tissues. Introduction of UBF in human lung fibroblast cells that do not express UBF resulted in an accelerated rate of cell growth; on the other hand, antisense oligodeoxynucleotides (ODNs) treatment of UBF-expressing hepatoma cell lines reduced the level of UBF protein, suppressed the colony formation capacity of these cells on soft agarose, and finally caused cell death. Annexin V binding analysis suggested that anti-UBF ODN-caused cell death might involve weak apoptosis, however, DNA laddering and cleavage of poly (ADP-ribose) polymerase were not observed in these ODN-treated cells. Expression profiling of the anti-UBF ODN-treated cells using a human cDNA array revealed that the expression of 30 genes was altered in response to the inhibition of UBF expression. Notably, UBF expression could increase the cell sensitivity to the chemotherapeutic reagent cis-diaminedichloroplatinum (II). We proposed that UBF is fundamental to the survival of cells expressing the gene, and is potential as a target for screening anti-cancer drugs and an indicator in selecting chemotherapeutic reagents.

Acylphosphatase possesses nucleoside triphosphatase and nucleoside diphosphatase activities

We have demonstrated that acylphosphatase possesses ATP-diphosphohydrolase (apyrase-like) activity. In fact, acylphosphatase first catalyses the hydrolysis of the gamma-phosphate group of nucleoside triphosphates, and then attacks the beta-phosphate group of the initially produced nucleoside diphosphates, generating nucleoside monophosphates. In contrast, it binds nucleoside monophosphates but does not catalyse their hydrolyses. The calculated k(cat) values for the nucleoside triphosphatase activity of acylphosphatase are of the same order of magnitude as those displayed by certain G-proteins. An acidic environment enhances the apyrase-like activity of acylphosphatase. The true nucleotide substrates of acylphosphatase are free nucleoside di- and triphosphates, as indicated by the Mg(2+) ion inhibition of the activity. We have also demonstrated that, although nucleoside triphosphates are still hydrolysed at pH 7.2 and 37 degrees C, in the presence of millimolar Mg(2+) concentrations this occurs at a lower rate. Taken together with the previously observed strong increase of acylphosphatase levels during induced cell differentiation, our findings suggest that acylphosphatase plays an active role in the differentiation process (as well as in other processes, such as apoptosis) by modulating the ratio between the cellular levels of nucleoside diphosphates and nucleoside triphosphates.

Evidence for tumor-host cooperation in regulating MMP-2 expression in human colon cancer

Matrix metalloproteinase 2 (MMP-2) facilitates tumor growth and metastasis in colon cancer. Although tumor cells may produce MMP-2, stromal cells, such as macrophages and fibroblasts, contribute significantly to MMP-2 synthesis in human tumors. We characterized four human colon cancer cell lines with differing biological behavior for MMP-2 expression. While the parent tumors from which the cell lines were derived all expressed MMP-2 mRNA, MMP-2 transcripts were detected in only one cell line, TF-17C, which is nontumorigenic in a nude mouse tumor model. TF-43C, which is tumorigenic and metastatic in the same tumor model, did not produce MMP-2, yet the tumors which arose from it after injection into nude mice did contain MMP-2 mRNA, suggesting a contribution from stromal cells. Co-culturing TF-43C with fibroblasts resulted in an increase in MMP-2 protein, whereas co-culturing with the nontumorigenic cell line TF-13Cm did not alter constitutive fibroblast MMP-2 secretion. Conditioned medium from TF-43C cells also stimulated fibroblast MMP-2 production. These data suggest that a soluble factor from TF-43C cells can stimulate fibroblast MMP-2 production and support the hypothesis that colon cancer cell interactions with stromal fibroblasts may be important determinants of tumor behavior in vivo.