Loss of MTSS1 Expression is an Independent Prognostic Factor for Hilar Cholangiocarcinoma

Downregulation of MTSS1 in acute myeloid leukemia is associated with a poor prognosis, chemotherapy resistance, and disease aggressiveness

Despite recent approval of targeted drugs for acute myeloid leukemia (AML) therapy, chemotherapy with cytosine arabinoside and anthracyclines remains an important pillar of treatment. Both primary and secondary resistance are frequent and associated with poor survival, yet the underlying molecular mechanisms are incompletely understood. In previous work, we identified genes deregulated between diagnosis and relapse of AML, corresponding to therapy naïve and resistant states, respectively. Among them was MTSS1, whose downregulation is known to enhance aggressiveness of solid tumors. Here we show that low MTSS1 expression at diagnosis was associated with a poor prognosis in AML. MTSS1 expression was regulated by promoter methylation, and reduced by cytosine arabinoside and the anthracycline daunorubicin. Experimental downregulation of MTSS1 affected the expression of numerous genes. It induced the DNA damage response kinase WEE1, and rendered human AML cell lines more resistant to cytosine arabinoside, daunorubicin, and other anti-cancer drugs. Mtss1 knockdown in murine MLL-AF9-driven AML substantially decreased disease latency, and increased leukemic burden and ex vivo chemotherapy resistance. In summary, low MTSS1 expression represents a novel factor contributing to disease aggressiveness, therapy resistance, and poor outcome in AML.

Metastasis suppressor 1 interacts with α-actinin 4 to affect its localization and regulate formation of membrane ruffling

Membrane ruffling plays an important role in the directed cell migration and escape of tumor cells from the monolayer. Metastasis suppressor 1 (MTSS1), also known as missing in metastasis, has been implicated in cell morphology, motility, metastasis, and development. Here, the dynamic interaction proteins associated with MTSS1 and involved in membrane ruffling were determined by cross-linking and mass spectrometry analysis. We identified α-actinin 4 (ACTN4) as an interacting protein and confirmed a direct interaction between MTSS1 and ACTN4. Moreover, co-expression of MTSS1 in fibroblasts recruited cytoplasmic ACTN4 to the cell periphery, at which point ruffling became thick and rigid. In MCF-7 cells, MTSS1 knockdown did not show an obvious effect on the cell shape or the distribution of endogenous ACTN4; however, ACTN4 overexpression transformed cell morphology from an epidermal- to a fibroblast-like shape, and further MTSS1 depletion significantly increased the ratio of fibroblast cells exhibiting prominent ruffling. Furthermore, biochemical data suggested that MTSS1 cross-linking with ACTN4 induced the formation of actin fiber bundles into more organized structures in vitro. These data indicated that MTSS1 might recruit cytoplasmic ACTN4 to the cell periphery and regulate cytoskeleton dynamics to restrict its performance in membrane ruffling.

Gene expression changes contribute to stemness and therapy resistance of relapsed acute myeloid leukemia: roles of SOCS2, CALCRL, MTSS1, and KDM6A

Relapse is associated with therapy resistance and is a major cause of death in acute myeloid leukemia (AML). It is thought to result from the accretion of therapy-refractory leukemic stem cells. Genetic and transcriptional changes that are recurrently gained at relapse are likely to contribute to the increased stemness and decreased therapy responsiveness at this disease stage. Despite the recent approval of several targeted drugs, chemotherapy with cytosine arabinoside and anthracyclines is still the mainstay of AML therapy. Accordingly, a number of studies have investigated genetic and gene expression changes between diagnosis and relapse of patients subjected to such treatment. Genetic alterations recurrently acquired at relapse were identified, but were restricted to small proportions of patients, and their functional characterization is still largely pending. In contrast, the expression of a substantial number of genes was altered consistently between diagnosis and recurrence of AML. Recent studies corroborated the roles of the upregulation of SOCS2 and CALCRL and of the downregulation of MTSS1 and KDM6A in therapy resistance and/or stemness of AML. These findings spur the assumption that functional investigations of genes consistently altered at recurrence of AML have the potential to promote the development of novel targeted drugs that may help to improve the outcome of this currently often fatal disease.

Overexpression of microRNA-96 is associated with poor prognosis and promotes proliferation, migration and invasion in cholangiocarcinoma cells via MTSS1

MicroRNA-96 (miR-96) has been revealed serve an oncogenic role in various types of cancer. However, the role of miR-96 in cholangiocarcinoma (CCA) development and progression is yet to be elucidated. Thus, the aim of the present study was to investigate the role of miR-96 in CCA. The expression pattern of miR-96 in CCA tissues and cell lines was evaluated using reverse transcription-quantitative PCR analysis. Kaplan-Meier curves and Cox regression analyses were conducted to investigate the prognostic significance of miR-96 in CCA. Cell Counting Kit-8 and Transwell assays were performed to identify the functions of miR-96. The association between miR-96 and metastasis suppressor-1 (MTSS1) was verified using a dual-luciferase assay. The results demonstrated that miR-96 expression levels were increased in CCA tissues and cell lines compared with those in adjacent normal tissues and normal human intrahepatic biliary epithelial cell lines, respectively. High expression levels of miR-96 were significantly associated with lymph node metastasis, differentiation and TNM stage. In addition, upregulated expression of miR-96 was associated with a poorer prognosis and was predicted to be a prognostic factor in patients with CCA. Overexpression of miR-96 in vitro promoted CCA cell proliferation, migration and invasion. Additionally, MTSS1 was identified as a direct target of miR-96. The results of the present study indicated the clinical and biological importance of miR-96 as an oncogene in CCA. miR-96 may represent an independent prognostic biomarker and may promote CCA cell proliferation, migration and invasion by targeting MTSS1.

Metadherin overexpression in perihilar cholangiocarcinoma is associated with lymph node metastasis and poor prognosis

Metadherin (MTDH) is a protein that is also named astrocyte elevated gene-1, and is highly expressed in a number of different tumor tissues. Although the expression of MTDH is associated with tumor invasion and recurrence, the expression of this protein in perihilar cholangiocarcinoma (PCCA) and its clinical use have not yet been investigated. In the present study, the expression of MTDH in patients with PCCA was investigated in order to determine its clinicopathological use. An immunohistochemical method was used to detect MTDH expression and the epithelial-mesenchymal transition markers E-cadherin and vimentin in 66 cases of PCCA. In addition to the expression of MTDH, the clinical and pathological data and the postoperative outcomes were analyzed. The MTDH positive expression rate was 48.5% (32/66) in PCCA. A significantly higher MTDH expression level was identified in the poor tumor differentiation group compared with the well differentiation group (P=0.007). In the positive lymph node metastasis group, a significantly higher MTDH expression level was revealed compared with the negative lymph node metastasis group (P=0.023). No association was noted with regard to the expression of MTDH and the variables age, sex, tumor diameter, tumor grade and tumor classification stage. Positive MTDH expression was significantly associated with high vimentin expression (P=0.037) compared with negative vimentin expression and inversely associated with positive E-cadherin expression compared with negative E-cadherin expression (P=0.030). Survival analysis suggested that the high MTDH expression group was associated with a worse overall survival (OS) rate and recurrence free survival (RFS) rate compared with the low MTDH expression group (P<0.001 and P=0.01, respectively). Cox regression analysis indicated that the Tumor-Node-Metastasis, surgery margin and high MTDH expression were independent OS and RFS factors for PCCA. MTDH expression may serve an important function in PCCA tumor growth and metastasis. Targeting MTDH may have important therapeutic applications for patients with PCCA.

Missing-in-metastasis B (MIM-B) combined with caveolin-1 promotes metastasis of hepatocellular carcinoma

BACKGROUND

Increasing amounts of evidence indicate that Missing in metastasis B (MIM-B) promotes cancer metastasis. Here, we sought to better understand the mechanism through which MIM-B promotes tumor metastasis in hepatocellular carcinoma (HCC).

METHODS

We performed confocal microscopy analysis to determine the distributions of MIM-B and caveolin-1 and conducted co-immunoprecipitation assays to detect the interactions between MIM-B and caveolin-1 in vitro. We performed transwell assays to analyze the invasive ability of HCC cells. Changes in the expression levels of key genes and some molecular makers were detected by immunohistochemistry and western blotting in HCC tissue samples.

RESULTS

We found that MIM-B co-localizes with caveolin-1 and demonstrated that MIM-B and caveolin-1 interact in vitro. Repressing MIM-B and caveolin-1 expression inhibited the epidermal growth factor receptor signaling pathway. We overexpressed MIM-B and caveolin-1 in Hep3B cells, which enhanced Hep3B cell invasiveness. Furthermore, MHCC97H cell invasiveness was significantly decreased in cells in which MIM-B and caveolin-1 expression was inhibited. Additionally, we found that MIM-B and caveolin-1 were expressed at higher levels in HCC tissues than in paired normal tissues. Moreover, HCC patients with MIM-B and caveolin-1 up-regulation experienced significantly worse outcomes than controls (P < 0.001), and HCC patients with high MIM-B and caveolin-1 expression levels often developed pulmonary metastasis (P < 0.001).

CONCLUSIONS

MIM-B combined with caveolin-1 promotes metastasis of HCC, and elevated MIM-B and caveolin-1 expression levels are associated with a poor prognosis in HCC patients; therefore, MIM-B and caveolin-1 may represent novel targets for the diagnosis and treatment of HCC.

Optimizing purification process of MIM-I-BAR domain by introducing atomic force microscope and dynamics simulations

MIM (missing in metastasis) is a member of I-BAR (inverse BAR) domain protein family, which functions as a putative metastasis suppressor. However, methods of gaining high purity MIM-I-BAR protein are barely reported. Here, by optimizing the purification process including changing the conditions of cell lysate and protein elution, we successfully purified MIM protein. The purity of the obtained protein was up to ∼90%. High-resolution atomic force microscope (AFM) provides more visual images, ensuring that we can observe the microenvironment around the target protein, as well as the conformations of the purification products following each purification process. MIM protein with two different sizes were observed on mica surface with AFM. Combining with molecular dynamics simulations, these molecules were revealed as MIM monomer and dimer. Furthermore, our study attaches importance to the usage of imidazole with suitable concentrations during the affinity chromatography process, as well as the removal of excessive imidazole after the affinity chromatography process. All these results indicate that the method described here was successful in purifying MIM protein and maintaining their natural properties, and is supposed to be used to purify other proteins with low solubility.

Loss of MTSS1 results in increased metastatic potential in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) has a 5-year survival rate of 7%. This dismal prognosis is largely due to the inability to diagnose the disease before metastasis occurs. Tumor cell dissemination occurs early in PDAC. While it is known that inflammation facilitates this process, the underlying mechanisms responsible for this progression have not been fully characterized. Here, we functionally test the role of metastasis suppressor 1 (MTSS1) in PDAC. Despite evidence showing that MTSS1 could be important for regulating metastasis in many different cancers, its function in PDAC has not been studied. Here, we show that loss of MTSS1 leads to increased invasion and migration in PDAC cell lines. Moreover, PDAC cells treated with cancer-associated fibroblast-conditioned media also have increased metastatic potential, which is augmented by loss of MTSS1. Finally, overexpression of MTSS1 in PDAC cell lines leads to a loss of migratory potential in vitro and an increase in overall survival in vivo. Collectively, our data provide insight into an important role for MTSS1 in suppressing tumor cell invasion and migration driven by the tumor microenvironment and suggest that therapeutic strategies aimed at increasing MTSS1 levels may effectively slow the development of metastatic lesions, increasing survival of patients with PDAC.

Elevated AQP1 Expression Is Associated With Unfavorable Oncologic Outcome in Patients With Hilar Cholangiocarcinoma

BACKGROUND

Hilar cholangiocarcinomas are malignant tumors with a poor prognosis. An early prediction of prognosis for patients may help us determine treatment strategies. Aquaporin 1 is a cell membrane channel involved in water transport, cell motility, and proliferation. Increasing evidences showed that aquaporin 1 played a role in tumor prognosis and diagnosis. The purpose of this study is to evaluate the role of aquaporin 1 in hilar cholangiocarcinoma.

METHODS

Here, we analyzed messenger RNA expression data of genes function as bile secretion in a data set of 169 samples using the R2 bioinformatic platform ( http://r2.amc.nl ). Quantitative polymerase chain reaction was performed to verify the gene expression in 17 hilar cholangiocarcinoma samples. Immunohistochemistry was also performed in a series of specimens from 62 hilar cholangiocarcinoma tissues, and its clinical significance was assessed by clinical correlation and Kaplan-Meier analyses.

RESULTS

All data were analyzed using the R2 web application, aquaporin 1 was selected for further analysis. The significant expression variation of aquaporin 1 among 17 cases with cholangiocarcinoma was also found using quantitative polymerase chain reaction. The expression level of aquaporin 1 protein significantly correlated with tumor-node-metastasis stage ( P = .002) and overall survival time ( P = .010). Higher aquaporin 1 expression indicated poor prognostic outcomes ( P <.05, log-rank test). Multivariate analysis also showed strong aquaporin 1 protein expression was an independent adverse prognosticator in hilar cholangiocarcinoma ( P = .002).

CONCLUSION

This study highlighted the prognostic value of aquaporin 1 in hilar cholangiocarcinoma. Strong aquaporin 1 expression predicts poor survival, regardless of pathological features. Immunohistochemical detection of aquaporin 1, as a prognostic marker, may contribute to predicting clinical outcome for patients with hilar cholangiocarcinoma.

PKM2 regulates neural invasion of and predicts poor prognosis for human hilar cholangiocarcinoma

BACKGROUND

The therapeutic and prognostic value of the glycolytic enzymes hexokinase, phosphofructokinase, and pyruvate kinase (PK) has been implicated in a variety of cancers, while their roles in treatment of and prognosis for hilar cholangiocarcinoma (HC) remain unclear. In this study, we determined the expression of PKM2 in and its impact on biology and clinical outcome of human HC.

METHODS

The regulation and function of PKM2 in HC pathogenesis was evaluated using human tissues, molecular and cell biology, and animal models, and its prognostic significance was determined according to its impact on patient survival.

RESULTS

We found that expression of hexokinase 1 and the M2 splice isoform of PK (PKM2) was upregulated in HC tissues and that this expression correlated with tumor recurrence and outcome. PKM2 expression was increased in HC cases with chronic cholangitis as demonstrated by isobaric tags for relative and absolute quantification. High PKM2 expression was highly correlated with high syndecan 2 (SDC2) expression and neural invasion. PKM2 downregulation led to a decrease in SDC2 expression. Treatment with metformin markedly suppressed PKM2 and SDC2 expression at both the transcriptional and posttranscriptional levels and inhibited HC cell proliferation and tumor growth.

CONCLUSIONS

PKM2 regulates neural invasion of HC cells at least in part via regulation of SDC2. Inhibition of PKM2 and SDC2 expression contributes to the therapeutic effect of metformin on HC. Therefore, PKM2 is an independent prognostic factor and potential therapeutic target for human HC.

SPARCL1 is a novel predictor of tumor recurrence and survival in hilar cholangiocarcinoma

Secreted protein acidic and rich in cysteines-like protein 1 (SPARCL1) has been implicated in tumor initiation, formation, and progression of various cancers, yet its role in hilar cholangiocarcinoma remains largely uncharacterized. In the present study, tissue microarrays containing resected hilar cholangiocarcinoma specimens from 92 patients were used to evaluate the expression of SPARCL1 protein by immunohistochemistry (IHC). In vitro assays were used to determine the effect of SPARCL1 overexpression on cell growth and migration. Loss of SPARCL1 expression was observed in 46 (50.0 %) of the 92 primary tumors. SPARCL1 expression is inversely associated with poorly or undifferentiation specimens (P = 0.030) in addition to lymph node metastasis (P = 0.047). Survival analysis demonstrated that SPARCL1 is an independent factor in predicting the outcome of patients with hilar cholangiocarcinoma. SPARCL1 overexpression suppressed tumor cell migration in vitro by inhibiting MMP-9, MMP-2, Vimentin, and Fibronectin expression, whereas did not inhibit cell proliferation in vitro. Our results suggest that loss of SPARCL1 is involved in the tumorigenesis of hilar cholangiocarcinoma and may serve as a novel molecular biomarker for patients' outcome.

Downregulation of MTSS1 expression is an independent prognosticator in squamous cell carcinoma of the lung

Background:

The metastasis suppressor 1 (MTSS1) is a newly discovered protein putatively involved in tumour progression and metastasis.

Material and Methods:

Immunohistochemical expression of MTSS1 was analysed in 264 non-small-cell lung carcinomas (NSCLCs).

Results:

The metastasis suppressor 1 was significantly overexpressed in NSCLC compared with normal lung (P=0.01). Within NSCLC, MTSS1 expression was inversely correlated with pT-stage (P=0.019) and histological grading (P<0.001). NSCLC with MTSS1 downregulation (<20%) showed a significantly worse outcome (P=0.007). This proved to be an independent prognostic factor in squamous cell carcinomas (SCCs; P=0.041), especially in early cancer stages (P=0.006).

Conclusion:

The metastasis suppressor 1 downregulation could thus serve as a stratifying marker for adjuvant therapy in early-stage SCC of the lung.