Heparanase overexpression participates in tumor growth of cervical cancer in vitro and in vivo

Expression of heparanase is associated with invasion, metastasis and angiogenesis of a variety of human cancers. However, the roles of heparanase in cervical cancer are not clear. The aim of this study is to determine whether up-regulation of heparanase expression can promote growth of cervical cancer in vitro and in vivo. Heparanase protein expression was analyzed in cervical cancer patients using immunohistochemistry. In addition, expression of heparanase was also examined in cervical cancer cell lines. A series of in vivo and in vitro assays was performed to elucidate the role of heparanase in tumor growth of cervical cancer. Positive rate of heparanase was 63.3 % (38/60) in cervical cancer patients by immunohistochemistry, and it was significantly correlated with tumor size and clinical stage (P < 0.05). Overexpression of heparanase inhibited apoptosis of cervical cancer cells. Moreover, ectopic overexpression of heparanase in cervical cancer cells promoted proliferation of cervical cancer cells in vitro and tumor growth in vivo. These results suggest that heparanase participates in tumor growth of cervical cancer by influencing the proliferation and apoptosis of cervical cancer cells, and heparanase could be used as an effective therapeutic target for cervical cancer.

Potential tumor suppressor NESG1 as an unfavorable prognosis factor in nasopharyngeal carcinoma

BACKGROUND

Recently we identified nasopharyngeal epithelium specific protein 1 (NESG1) as a potential tumor suppressor in nasopharyngeal carcinoma (NPC). The purpose of this study is to investigate the involvement of NESG1 in tumor progression and prognosis of human NPC.

METHODOLOGY/PRINCIPAL FINDINGS

NESG1 protein expression in NPC was examined. Survival analysis was performed using Kaplan-Meier method. The effect of NESG1 on cell proliferation, migration, and invasion were also investigated.

RESULTS

NESG1 expression was downregulated in atypical hyperplasia and NPC samples compared to normal and squamous nasopharynx tissues. Reduced protein expression was negatively associated with the status of NPC progression. Patients with lower NESG1 expression had a shorter overall survival and disease-free time than did patients with higher NESG1 expression. Multivariate analysis suggested NESG1 expression as an independent prognostic indicator for NPC patient survival. Proliferation, migration, and invasion ability were significantly increased in cell lines following lentiviral-mediated shRNA suppression of NESG1 expression. Microarray analysis indicated that NESG1 participated in multiple pathways, including MAPK signaling and cell cycle regulation. Finally, DNA methylation microarray examination revealed a lack of hypermethylation at the NESG1 promoter, suggesting other mechanisms are involved in suppressing NESG1 expression in NPC.

CONCLUSION

Our studies are the first to demonstrate that decreased NESG1 expression is an unfavorable prognostic factor for NPC.

Kindlin-2 Acts as a Key Mediator of Lung Fibroblast Activation and Pulmonary Fibrosis Progression

Pulmonary fibrosis is a progressive and fatal lung disease characterized by activation of lung fibroblasts and excessive deposition of collagen matrix. We show here that the concentrations of kindlin-2 and its binding partner PYCR1, a key enzyme for proline synthesis, are significantly increased in the lung tissues of human patients with pulmonary fibrosis. Treatment of human lung fibroblasts with TGF-β1 markedly increased the expression of kindlin-2 and PYCR1, resulting in increased kindlin-2 mitochondrial translocation, formation of the kindlin-2-PYCR1 complex, and proline synthesis. The concentrations of the kindlin-2-PYCR1 complex and proline synthesis were markedly reduced in response to pirfenidone or nintedanib, two clinically approved therapeutic drugs for pulmonary fibrosis. Furthermore, depletion of kindlin-2 alone was sufficient to suppress TGF-β1-induced increases of PYCR1 expression, proline synthesis, and fibroblast activation. Finally, using a bleomycin mouse model of pulmonary fibrosis, we show that ablation of kindlin-2 effectively reduced the concentrations of PYCR1, proline, and collagen matrix and alleviate the progression of pulmonary fibrosis in vivo. Our results suggest that kindlin-2 is a key promoter of lung fibroblast activation, collagen matrix synthesis, and pulmonary fibrosis, underscoring the therapeutic potential of targeting the kindlin-2 signaling pathway for control of this deadly lung disease.

Cancer stem cell characteristics, ALDH1 expression in the invasive front of nasopharyngeal carcinoma

The invasive tumor front underlies the biological aggressiveness and epithelial-mesenchymal transition (EMT) in various human malignances. However, the molecular and biological characteristics of invasive tumor front in NPC have rarely been described. Additionally, the features of cancer stem cells (CSCs) in the invasive front of tumors and its correlation with EMT also remain elusive. Our study was to investigate the expression of CSCs marker aldehyde dehydrogenase 1 (ALDH1) in the invasive front of nasopharyngeal carcinoma (NPC) and its clinical significance. Immunohistochemistry was mainly used to detect ALDH1 expression in the invasive front of NPC. The relationship between ALDH1 expression and EMT-associated markers was also examined. ALDH1 expression in the invasive front correlated strongly with lymphatic invasion (p<0.001), T classification (p=0.001), M classification (p<0.001), clinical stage (p<0.001), and local recurrence (p=0.008). ALDH1 overexpression in the invasive front contributed to worse survival of NPC, particularly in patients with early stage (T1-T2 or N0-N1) (p<0.001 and p=0.002, respectively), though it was not an independent prognostic factor (p=0.196). Furthermore, in the invasive front of NPC, ALDH1 expression correlated significantly with EMT-related biomarkers E-cadherin (p=0.026), Vimentin (p<0.001), Periostin (p<0.001), and Snail (p<0.001), but not with β-catenin (p=0.143). Our findings demonstrate first that ALDH1 expression in the invasive front links closely with EMT characteristics and tumor aggressiveness, which might provide a useful prognostic marker for NPC patients.

LATS2 as a poor prognostic marker regulates non-small cell lung cancer invasion by modulating MMPs expression

Large tumor suppressor 2 (LATS2) plays significant roles in tumorigenesis and cancer progression. This study was aimed to analyze the correlation between LATS2 expression and clinicopathologic features and its prognostic significance in non-small cell lung cancer (NSCLC). LATS2 expression was examined in 73 NSCLC clinical specimens and 22 normal lung tissues using immunohistochemistry. Low levels of LATS2 protein were inversely associated with the T classification (P=0.001), N classification (P=0.005) and clinical stage (P=0.001) in NSCLC patients. Patients with lower LATS2 expression had a significantly shorter overall survival than patients with high LATS2 expression. Multivariate analysis suggested that low expression of LATS2 was an independent prognostic indicator (P=0.002) for the survival of patients with NSCLC. Furthermore, overexpression of LATS2 resulted in mobility inhibition in NSCLC cell lines A549 and H1299, and reduced protein level of matrix metalloproteinase-2 (MMP-2) and MMP-9. On the contrary, LATS2 siRNA treatment enhanced cell mobility and increased MMP-2 and MMP-9 protein expression level. In conclusion, low expression of LATS2 is a potential unfavorable prognostic factor and promoted cell invasion and migration in NSCLC.

Survivin promotes the invasion of human colon carcinoma cells by regulating the expression of MMP‑7

Increased expression levels of survivin are crucial for invasion activity in several types of human cancer, including colon carcinoma. However, the molecular mechanisms whereby survivin regulates cancer invasion have not been completely elucidated. To the best of our knowledge, this study is the first to investigate the role of matrix metalloprotease‑7 (MMP‑7) in cell invasion that is induced by survivin by using in vitro assays, including western blot, immunofluorescence and qPCR analyses. The results demonstrated that the ectopic expression of survivin significantly promoted the invasive activity of colon carcinoma cells (SW620 and HCT‑116) and resulted in increased levels of MMP‑7 activation. By contrast, the small interfering RNA (siRNA)‑based knockdown of survivin markedly reduced cell migration and led to a dose‑dependent decrease in MMP‑7 expression levels. Compared with the controls, knockdown of MMP‑7 by siRNA in colon carcinoma cells led to reduced invasion ability, whereas no obvious changes were observed when MMP‑7 expression was silenced in survivin‑overexpressing colon carcinoma cells. These findings demonstrate that MMP‑7 is crucial for survivin‑mediated invasiveness, suggesting that the survivin‑mediated MMP‑7 signaling pathway is a potential therapeutic target for the treatment of colon carcinoma.

ESRG is critical to maintain the cell survival and self-renewal/pluripotency of hPSCs by collaborating with MCM2 to suppress p53 pathway

The mechanisms of self-renewal and pluripotency maintenance of human pluripotent stem cells (hPSCs) have not been fully elucidated, especially for the role of those poorly characterized long noncoding RNAs (lncRNAs). ESRG is a lncRNA highly expressed in hPSCs, and its functional roles are being extensively explored in the field. Here, we identified that the transcription of ESRG can be directly regulated by OCT4, a key self-renewal factor in hPSCs. Knockdown of ESRG induces hPSC differentiation, cell cycle arrest, and apoptosis. ESRG binds to MCM2, a replication-licensing factor, to sustain its steady-state level and nuclear location, safeguarding error-free DNA replication. Further study showed that ESRG knockdown leads to MCM2 abnormalities, resulting in DNA damage and activation of the p53 pathway, ultimately impairs hPSC self-renewal and pluripotency, and induces cell apoptosis. In summary, our study suggests that ESRG, as a novel target of OCT4, plays an essential role in maintaining the cell survival and self-renewal/pluripotency of hPSCs in collaboration with MCM2 to suppress p53 signaling. These findings provide critical insights into the mechanisms underlying the maintenance of self-renewal and pluripotency in hPSCs by lncRNAs.

TBL1X and Flot2 form a positive feedback loop to promote metastasis in nasopharyngeal carcinoma

Metastasis is the main cause of death in patients with nasopharyngeal carcinoma (NPC). The molecular mechanisms underlying the metastasis of NPC remain to be elucidated. TBL1X has been shown abnormally expressed in diverse cancers. However, the role and mechanism of TBL1X in NPC remain unknown. Here, we showed TBL1X expression was significantly higher in metastatic NPC tissues compared to non-metastatic tissues and significantly correlated with TNM stage and metastasis of NPC patients. In addition, NPC patients with high TBL1X expression had a poor prognosis. TBL1X interacted with TCF4 to trans-activate Flot2 expression. TBL1X promoted NPC cell migration and invasion in vitro and in vivo through Flot2. Moreover, Flot2 increased the expression of TBL1X by upregulating c-myc, which was identified to be a positively regulatory transcription factor of TBL1X. TBL1X could restore the functional changes of NPC cells resulting from Flot2 alteration. TBL1X and Flot2 were positively correlated in NPC. Patients with high expression of both TBL1X and Flot2 possessed poorer overall survival (OS) and disease-free survival (DFS) compared to patients with high expression of any single one of the two proteins. Our findings demonstrate that TBL1X and Flot2 positively regulate each other to promote NPC metastasis, which provides novel potential molecular targets for NPC treatment.

FLOT2 promotes nasopharyngeal carcinoma progression through suppression of TGF-β pathway via facilitating CD109 expression

In nasopharyngeal carcinoma (NPC), the TGF-β/Smad pathway genes are altered with inactive TGF-β signal, but the mechanisms remain unclear. RNA-sequencing results showed that FLOT2 negatively regulated the TGF-β signaling pathway via up-regulating CD109 expression. qRT-PCR, western blot, ChIP, and dual-luciferase assays were used to identify whether STAT3 is the activating transcription factor of CD109. Co-IP immunofluorescence staining assays were used to demonstrate the connection between FLOT2 and STAT3. In vitro and in vivo experiments were used to detect whether CD109 could rescue the functional changes of NPC cells resulting from FLOT2 alteration. IHC and Spearman correlation coefficients were used to assay the correlation between FLOT2 and CD109 expression in NPC tissues. Our results found that FLOT2 promotes the development of NPC by inhibiting TGF-β signaling pathway via stimulating the expression of CD109 by stabilizing STAT3, which provides a potential therapeutic strategy for NPC treatment.

Overexpressed DNA-binding protein inhibitor 2 as an unfavorable prognosis factor promotes cell proliferation in nasopharyngeal carcinoma

The aim of the present study was to analyze the expression of DNA-binding protein inhibitor 2 (ID2) in nasopharyngeal carcinoma (NPC) and its correlation with clinicopathological features. It was found that the expression of ID2 was significantly increased in NPC cells when compared with that in NP69 cell line. Similar level of ID2 cytoplasmic expression was observed in NPC when compared with that in non-cancerous nasopharynx tissues. However, the level of ID2 in nucleus was increased in NPC when compared with that in normal nasopharynx tissues. Furthermore, the higher expression level of nuclear ID2 was significantly associated with tumor size (T classification), lymph node metastasis (N classification), and clinical stage. Patients with increased ID2 expression level had poorer overall survival rates than those with low ID2 levels. The inhibition of ID2 expression in NPC cell line SUNE1 by lentiviral-mediated short hairpin RNA could suppress cell proliferation and colony formation, but did not disrupt cell migration. Knocking down the expression of ID2 by RNA interference could down-regulate the expression of Snail, suggesting that ID2-promoted cell growth, partially attributing to the regulation of Snail activity in NPC. Our study demonstrated that over-expression of ID2 protein is an unfavorable prognostic factor which promotes cell proliferation in NPC.

ThermomiR-377-3p-induced suppression of Cirbp expression is required for effective elimination of cancer cells and cancer stem-like cells by hyperthermia

BACKGROUND

In recent years, the development of adjunctive therapeutic hyperthermia for cancer therapy has received considerable attention. However, the mechanisms underlying hyperthermia resistance are still poorly understood. In this study, we investigated the roles of cold‑inducible RNA binding protein (Cirbp) in regulating hyperthermia resistance and underlying mechanisms in nasopharyngeal carcinoma (NPC).

METHODS

CCK-8 assay, colony formation assay, tumor sphere formation assay, qRT-PCR, Western blot were employed to examine the effects of hyperthermia (HT), HT + oridonin(Ori) or HT + radiotherapy (RT) on the proliferation and stemness of NPC cells. RNA sequencing was applied to gain differentially expressed genes upon hyperthermia. Gain-of-function and loss-of-function experiments were used to evaluate the effects of RNAi-mediated Cirbp silencing or Cirbp overexpression on the sensitivity or resistance of NPC cells and cancer stem-like cells to hyperthermia by CCK-8 assay, colony formation assay, tumorsphere formation assay and apoptosis assay, and in subcutaneous xenograft animal model. miRNA transient transfection and luciferase reporter assay were used to demonstrate that Cirbp is a direct target of miR-377-3p. The phosphorylation levels of key members in ATM-Chk2 and ATR-Chk1 pathways were detected by Western blot.

RESULTS

Our results firstly revealed that hyperthermia significantly attenuated the stemness of NPC cells, while combination treatment of hyperthermia and oridonin dramatically increased the killing effect on NPC cells and cancer stem cell (CSC)‑like population. Moreover, hyperthermia substantially improved the sensitivity of radiation‑resistant NPC cells and CSC‑like cells to radiotherapy. Hyperthermia noticeably suppressed Cirbp expression in NPC cells and xenograft tumor tissues. Furthermore, Cirbp inhibition remarkably boosted anti‑tumor‑killing activity of hyperthermia against NPC cells and CSC‑like cells, whereas ectopic expression of Cirbp compromised tumor‑killing effect of hyperthermia on these cells, indicating that Cirbp overexpression induces hyperthermia resistance. ThermomiR-377-3p improved the sensitivity of NPC cells and CSC‑like cells to hyperthermia in vitro by directly suppressing Cirbp expression. More importantly, our results displayed the significantly boosted sensitization of tumor xenografts to hyperthermia by Cirbp silencing in vivo, but ectopic expression of Cirbp almost completely counteracted hyperthermia-mediated tumor cell-killing effect against tumor xenografts in vivo. Mechanistically, Cirbp silencing-induced inhibition of DNA damage repair by inactivating ATM-Chk2 and ATR-Chk1 pathways, decrease in stemness and increase in cell death contributed to hyperthermic sensitization; conversely, Cirbp overexpression-induced promotion of DNA damage repair, increase in stemness and decrease in cell apoptosis contributed to hyperthermia resistance.

CONCLUSION

Taken together, these findings reveal a previously unrecognized role for Cirbp in positively regulating hyperthermia resistance and suggest that thermomiR-377-3p and its target gene Cirbp represent promising targets for therapeutic hyperthermia.

[Influence of celecoxib on invasiveness of human high-metastatic nasopharyngeal carcinoma cell line CNE-2Z]

OBJECTIVE

To investigate the effect and mechanism (a selective cyclooxygenase-2 inhibitor) on invasive ability of human nasopharyngeal carcinoma (NPC) line CNE-2Z.

METHODS

The proliferation of NPC cells was examined by MTT assay. The invasive and migrating ability of NPC cells was detected with transwell chamber. E-cadherin protein expression was detected by immunocytochemistry and the expressions of Cox-2 and E-cadherin mRNA were analyzed by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

MTT showed that celecoxib inhibited CNE-2Z proliferation in dose-dependent manner, the survival rate of cells treated with 25, 50, 100 µmol/L celecoxib (x(-) ± s) for 24 h was (94.75 ± 1.34)%, (91.77 ± 2.70)%, (64.54 ± 1.20)%, respectively, and the survival rate of cells treated for 48 h was (88.41 ± 1.28)%, (78.84 ± 1.56)%, (52.46 ± 2.25)%, respectively, the concentration of 50% inhibition concentration of a substance (IC50) was 100 µmol/L, the difference was statistically significant between different concentration groups in the same time-point (respectively, F were 462.204 and 1328.306, P < 0.01). Treated with different concentrations of celecoxib (0, 25, 50 µmol/L) for 24, the cell numbers (x(-) ± s) through PVPF by tumor invasion assay were (263.7 ± 13.5), (185.3 ± 8.7) and (144.0 ± 8.2), the difference was statistically significant between the experimental and control group (F = 102.089, P < 0.01). Immunocytochemistry showed that celecoxib significantly induced the increase of E-cadherin protein expression, also with a dose-dependence in 0 µmol/L, 25 µmol/L, 50 µmol/L group was (21.7 ± 2.6), (28.7 ± 2.4), (40.3 ± 1.3), and 50 µmol/L group increased significantly (F = 78.637, P < 0.01). RT-PCR showed that celecoxib reduced the expression of Cox-2 mRNA expression in 25, 50 µmol/L group decreased significantly compared with the control group (respectively, t were 23.950 and 36.651, P < 0.01), but it enhanced the expression of E-cadherin mRNA expression in 25, 50 µmol/L group was significantly higher (respectively, t were 35.829 and 81.497, P < 0.01).

CONCLUSION

Celecoxib can inhibits the invasive ability of NPC cell line CNE-2Z, which possibly relates with the upregulated expression of E-cadherin.

[Effects of Epstein-Barr virus latent membrane protein 1 on metastasis of human nasopharyngeal carcinoma cell lines]

BACKGROUND & OBJECTIVE

Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) plays an important role in the metastasis of nasopharyngeal carcinoma (NPC). This study was to investigate the effects of EBV LMP1 on the metastasis of NPC cell lines, and explore potential mechanism.

METHODS

The expression of LMP1, E-cadherin and intercellular adhesion molecule-1 (ICAM-1) in human NPC cell lines CNE1 (well differentiated) and CNE1-GL (CNE1 cells transfected with LMP1) were detected by SP immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. The cell-cell adhesion assay, the cell-matrix adhesion assay, the wound-induced migration assay and the migration assay were used to investigate the effects of LMP1 on adhesive and metastatic abilities of NPC cells.

RESULTS

The positive rates of LMP1 and ICAM-1 were significantly lower in CNE1 cells than in CNE1-GL cells [0% vs. (96.60+/-3.03)%, P<0.01; (5.27+/-1.45)% vs. (93.33+/-4.23)%, P<0.01]; the positive rate of E-cadherin was significantly higher in CNE1 cells than in CNE1-GL cells [(37.47+/-1.50)% vs. (19.53+/-1.92)%, P<0.01]. The expression of E-cadherin was significantly inhibited (P<0.01), while the expression of ICAM-1 was significantly increased (P<0.01) in CNE1-GL cells as compared with those in CNE1 cells. The cell-cell adhesive ability of CNE1-GL cells was lower than that of CNE1 cells (P<0.05). The cell-matrix adhesive ability of CNE1-GL cells was significantly higher than that of CNE1 cells (0.60+/-0.03 vs. 0.46+/-0.01, P<0.01). The number of migrated CNE1-GL cells was higher than that of migrated CNE1 cells (119.3+/-6.0 vs. 46.3+/-7.0, P<0.05).

CONCLUSION

By inhibiting E-cadherin expression and enhancing ICAM-1 expression, LMP1 may reduce the cell-cell adhesive ability and improve the cell-matrix adhesive ability and migratory ability of NPC cells, which may play roles in the invasion and metastasis of NPC.