ATF4 promotes lung cancer cell proliferation and invasion partially through regulating Wnt/ß-catenin signaling.

Activating transcription factor 4 (ATF4) is a member of the cAMP response element binding (CREB) protein family and has been reported to participate in cancer progression; however, its molecular mechanism is not fully understood. In this study, we investigated the function of ATF4 in non-small cell lung cancer and its molecular regulation. We detected cytoplasmic and nuclear ATF4 expression in lung cancer A549, H1299, and LK2 cells, and the total expression of ATF4 was higher than that in HBE cells (p < 0.05). Higher nuclear ATF4 expression was detected in all these cells compared to cytoplasmic ATF4 expression (p < 0.05). Overexpression of ATF4 in A549 cells significantly promoted cancer cell growth and invasion (p < 0.05). Expression of Wnt signaling molecules, including ß-catenin, MMP7, and cyclin D1, and the activity of canonical Wnt signaling were also significantly promoted by ATF4 (p < 0.05). ICG001, a canonical Wnt signaling inhibitor that selectively inhibits ß-catenin/ cyclic adenosine monophosphate response element binding protein (CBP) interaction, significantly inhibited cancer cell invasion and Wnt signaling. The function of ATF4 was also significantly inhibited by ICG001 (p < 0.05). However, compared to treatment with ICG001, the invasion ability of cancer cells treated with both ICG001 and ATF4 cDNA significantly increased (p < 0.05), which indicates that the function of ATF4 was not dependent only on Wnt/ß-catenin signaling. The function of ATF4 in the regulation of ß-catenin expression was not significantly affected by ICG001 (p > 0.05). The function of ATF4 to promote the activity of Wnt/ß-catenin signaling in cancer cells was abolished by treatment with ICG001 (p > 0.05). These results indicate that ATF4 may contribute to lung cancer progression at least partly by regulating Wnt/ß-catenin signaling.

Ube2S regulates Wnt/ß-catenin signaling and promotes the progression of non-small cell lung cancer.

Ubiquitin conjugating enzyme E2S (Ube2S) plays important roles in cancer development in some malignant tumors. However, the functions and related molecular network of Ube2S in non-small cell lung cancer are not fully understood. In the current study, we examined the expression of Ube2S in non-small cell lung cancer and its clinicopathological significance. We also investigated the molecules and pathways regulated by Ube2S. An immunostaining study showed that the positive rate of Ube2s expression in lung cancer tissues was higher than that in normal lung tissues (p < 0.05). Upregulated Ube2S expression in cancer tissues significantly correlated with clinical progression (TNM III versus I + II), lymph node metastasis, and shorter survival time of the patients (p < 0.05). When Ube2S was overexpressed in A549 cells, the abilities of these cells to proliferate and migrate were increased (p < 0.05). Moreover, Ube2S significantly upregulated the expression of ß-catenin, cyclin D1, and MMP7 (novel molecules of the Wnt/ß-catenin pathway), and the activity of this pathway (p < 0.05). In addition, a Wnt/ß-catenin signaling inhibitor effectively abolished the function of Ube2S. These results indicate that Ube2S may be a novel marker contributing to lung cancer development, possibly through regulating canonical Wnt signaling.

Zbed3 promotes proliferation and invasion of lung cancer partly through regulating the function of Axin-Gsk3ß complex.

Our previous work showed that Zbed3 is overexpressed in nonsmall cell lung cancer and that down-regulation of Zbed3 inhibited ß-catenin expression and cancer cell proliferation and invasiveness. Here, we investigated Zbed3's ability to promote lung cancer cell proliferation and invasion and the involvement of the Axin/TPC/glycogen synthase kinase 3ß (Gsk-3ß) complex to the response. Coimmunoprecipitation assays showed that wild-type Zbed3 bound to Axin but a Zbed3 mutant lacking the Axin binding site did not. In A549 and H1299 lung cancer cells, Zbed3 overexpression promoted cancer cell proliferation and invasiveness, as well as Wnt signalling and expression of downstream mediators, including ß-catenin, cyclin D1 and MMP7 (P < 0.05). In contrast, the Zbed3 mutant failed to enhance ß-catenin expression (P > 0.05), and its ability to promote cancer cell proliferation and invasiveness was much less than wild-type Zbed3 (P < 0.05). The ability of Zbed3 to increase ß-catenin levels was abolished by Axin knockdown in A549 cells (P > 0.05). Similarly, treating the cells with a GSK-3ß inhibitor abolished Zbed3's ability to increase ß-catenin levels and Wnt signalling. These results indicate that Zbed3 enhances lung cancer cell proliferation and invasiveness at least in part by inhibiting Axin/adenomatous polyposis coli/GSK-3ß-mediated negative regulation of ß-catenin levels.

Identifying UBA2 as a proliferation and cell cycle regulator in lung cancer A549 cells.

Ubiquitin activating enzyme 2 (UBA2) is a basic component of E1-activating enzyme in the SUMOylation system. Expression and function of UBA2 in human cancers are largely unknown. In this study we investigate UBA2 expression the function in human non-small-cell lung cancer. Immunochemistry study showed that UBA2 was overexpressed in cancer tissues (53.3%, 40 of 75) compared with normal lung tissues (14.3%, 4 of 28) (P < 0.05). Immunostaining of UBA2 was mainly detected in nucleus. Overexpression of UBA2 in cancer tissues was significantly associated with poor differentiation, large tumor size ( > 5.0 cm), higher T stages (T3 + 4), lymph node metastasis and advanced TNM stages (III + IV). In vitro study showed that UBA2 was expressed in A549, 95D, H1975, and H1299 cells. Knockdown of UBA2 in A549 cells significantly inhibited cancer cell proliferation and upregulated cancer cell apoptosis (P < 0.05). Cell cycle analysis showed that knockdown of UBA2 in A549 cell significantly increased the G1 and G2/M phase cells and reduced the S phase cells (P < 0.05). Gene expression profile after knockdown of UBA2 in A549 cells showed that the most related function was cell cycle, cell death and survival, and cellular growth and proliferation. Western blot analysis study showed that knockdown of UBA2 significantly inhibited expression of poly(ADP-ribose) polymerase 1, mini-chromosome maintenance 7 (MCM7), MCM2, MCM3 and MCM7. These results indicated that UBA2 was a critical cell cycle and proliferation regulator and may be a novel cancer marker in this malignant tumor.

ZCCHC9 promotes proliferation and invasion of lung cancer through regulating the JNK pathway.

ZCCHC9 is a type of CCHC type zinc-finger containing protein which was found to be expressed in some tissues including brain and testicles in mice. Expression and function of ZCCHC9 in human tissues including cancer was largely unknown. In this study, we investigated the expression and function of ZCCHC9 in human non-small cell lung cancer (NSCLC) and the related molecular mechanism. Immunochemistrical standing showed that ZCCHC9 was mainly located in the nucleus in bronchial epithelial cells and epithelial cells of submucosal glands (58.3% [14/24]). But in NSCLC cells ZCCHC9 was mainly located in the cytoplasm and the positive rate was 54.5% (60/110). Ectopic cytoplasmic expression of ZCCHC9 in cancer tissues was significantly associated with advanced TNM stages (III+IV), lymph node metastasis, and poor clinical outcome (P < 0.05). Overexpression of cytoplasmic ZCCHC9 using transfection of ZCCHC9 cDNA in A549 and NCI-H1299 cells significantly upregulated the proliferation and invasion of these cancer cells in vitro (P < 0.05). Western blot study showed that overexpression of cytoplasmic ZCCHC9 significantly upregulated expression of p-JNK, Cyclin D1, and MMP7 (P < 0.05). Next we used the inhibitor of JNK pathway to inhibit the activity of the JNK pathway and the results showed that co-addition of SP600125 significantly abolished the function of ZCCHC9 to promote the proliferation and invasion of cancer cells. These results indicate that cytoplasmic ZCCHC9 could promote the proliferation and invasion of NSCLC through the JNK pathway and may be a promising cancer maker.

The function of BED finger domain of Zbed3 in regulating lung cancer cell proliferation.

Zbed3, a BED finger domain-containing protein was found to promote cancer proliferation by regulating ß-catenin expression through interacting with Axin. But whether and how BED finger domain function in regulating cancer proliferation is unknown. We constructed five mutants of Zbed3, which lacks the Axin-Zbed3 binding site, and the 43 to 52, 69 to 77, 87 to 92, and 97 to 104 sequences in BED finger domain, respectively and named them as Z-A, Z1, Z2, Z3, and Z4. Transfection of both wild-type of Zbed3 and the mutants Z1, Z3, and Z4 (P < 0.05), but not Z2 (P > 0.05) significantly upregulated ß-catenin expression in NCI-H1299 cells. Overexpression of both wild-type of Zbed3 and the mutants Z1, Z3, and Z4 (P < 0.05) but not Z2 (P > 0.05) significantly promoted cancer cell proliferation and invasion. The ability of proliferation (P < 0.05) but not invasion (P < 0.05) of cancer cells transfected with Z1 and Z4 was significantly lower than that with wild-type Zbed3 and Z3. Overexpression of wild-type Zbed3 (P < 0.05) but not the mutant Z-A, which lacks the binding site with Axin and Z2 (P > 0.05) significantly upregulated the interaction of Axin and Zbed3, ß-catenin expression and the activity of Wnt signaling. Both overexpression of wild-type Zbed3 and the mutant Z1 and Z4 significantly upregulated the activity of Wnt signaling and promoted cancer cell proliferation (P < 0.05) but only overexpression of wild-type Zbed3 (P < 0.05), but not the mutant Z1, and Z4 (P > 0.05), significantly upregulated the expression of proliferating cell nuclear antigen (PCNA) in NCI-H1299 cells. These results indicate that Zbed3 may promote lung cancer cell proliferation through regulating PCNA expression besides regulating ß-catenin expression and BED finger domain can impact on this function.

TIMM50 promotes tumor progression via ERK signaling and predicts poor prognosis of non-small cell lung cancer patients.

TIMM50 (Translocase of the inner mitochondrial membrane 50), also called TIM50, plays an essential role in mitochondrial membrane transportation. The existing literature suggests that TIMM50 may perform as an oncogenetic protein in breast cancer. However, the molecular mechanism, especially in human non-small cell lung cancer (NSCLC), is uncertain to date. In the present study, using immunohistochemistry, we found that TIMM50 expression significantly correlated with larger tumor size (P = 0.049), advanced TNM stage (P = 0.001), positive regional lymph node metastasis (P = 0.007), and poor overall survival (P = 0.001). Proliferation and invasion assay showed that TIMM50 dramatically promoted the ability of proliferation and invasion of NSCLC cells. Subsequent Western blotting results revealed that TIMM50 enhanced the expression of Cyclin D1 and Snail, and inhibited the expression of E-cadherin. Moreover, TIMM50 facilitated the expression of phosphorylated ERK and P90RSK. Incorporation of ERK inhibitor counteracted the upregulating expression of CyclinD1, and Snail, and downregulating expression of E-cadherin expression induced by TIMM50 overexpression. In conclusion, our data indicated that TIMM50 facilitated tumor proliferation and invasion of NSCLC through enhancing phosphorylation of its downstream ERK/P90RSK signaling pathway. We speculated that TIMM50 might be a useful prognosis marker of NSCLC patients.

Hes3 Enhances the Malignant Phenotype of Lung Cancer through Upregulating Cyclin D1, Cyclin D3 and MMP7 Expression.

Hes3 is a basic helix-loop-helix factor gene, which was found to be involved in neural cell differentiation. Expression and clinicopathological significance of Hes3 in non-small cell lung cancer was not clear. In this study, we used immunohistochemistry to examine Hes3 expression in normal human lung and non-small cell lung cancer tissues. Hes3 expression was detected in cytoplasm and nucleus. Hes3 expression in bronchial epithelial cells and epithelial cells of submucosal glands was relatively weak and the positive rate was of 30.3% (10/33). Hes3 expression in non-small cell lung cancer tissues (51.8% (58/112)) was significantly higher than that in normal lung tissues (p < 0.05). Hes3 expression in cancer tissues was significantly associated with poor differentiation, advanced TNM stages, lymph node metastasis, and a shorter patient survival time (p < 0.05). In vitro study showed that overexpression of Hes3 in A549 cells significantly promoted cancer cell proliferation and invasion, while inhibition of Hes3 expression significantly downregulated cancer cell proliferation and invasion (p < 0.05). Western blotting showed that overexpression of Hes3 significantly upregulated expression of Cyclin D1, Cyclin D3, and MMP7 in A549 cells, while inhibition of Hes3 expression in LK2 cells significantly downregulated the expression of these molecules (p < 0.05). These results indicated that Hes3 may contribute to the malignant phenotype of non-small cell lung cancer, possibly through regulation of Cyclin D1, Cyclin D3, and MMP7, and may be a promising cancer marker.

NDRG1 Downregulates ATF3 and Inhibits Cisplatin-Induced Cytotoxicity in Lung Cancer A549 Cells.

N-myc downstream regulated gene 1 (NDRG1) plays a variety of roles in human cancers. Our previous studies showed that NDRG1 expression is elevated in non-small cell lung cancer and contributes to cancer growth. However, its function in apoptosis and chemoresistance in malignant tumors, including lung cancer, is not yet fully understood. In this study, we investigated the roles of NDRG1 in chemoresistance to cisplatin in lung cancer cells. We found that overexpression of NDRG1 significantly reduced cisplatin-induced cytotoxicity in lung cancer A549 cells, while overexpression of activating transcription factor 3 (ATF3), a stress-inducible gene found to be associated with apoptosis in some human cancers, significantly promoted cytotoxicity (P < 0.05). Further investigation showed that overexpression of NDRG1 significantly downregulated ATF3 and P53 expression in A549 cells, while overexpression of ATF3 significantly upregulated P53 expression (P < 0.05). In addition, cisplatin significantly upregulated ATF3, phospho-P53(ser46), and cleaved caspase 3 expression in lung cancer cells, but overexpression of NDRG1 in the presence of cisplatin reduced the level of these proteins elevated by cisplatin (P < 0.05). While, overexpression of ATF3 significantly promoted the cytoxicity induced by cisplatin in 1299 cells (p<0.05) (Figure 4), but overexpression of NDRG1 didn't regulate the cytoxicity induced by cisplatin (p>0.05). These results indicate that NDRG1 may contribute to cisplatin-resistance in lung cancer, possibly due to its function in the regulation of ATF3 expression.

Endometriosis in the rectum accompanied by hemorrhoids leading to diagnostic pitfalls: a rare case report.

BACKGROUND: Hemorrhoid is a common anorectal disease. Hemorrhoids accompanied by endometriosis are unusual. As endometriosis in the rectum may mimic many other diseases, including cancer and inflammation, its diagnosis may be difficult, especially when it is combined with other diseases. CASE PRESENTATION: Here, we present a rare case of a patient with hemorrhoids accompanied by endometriosis in the rectum. The endometriosis mass was detected by digital rectal examination and CT scan and confirmed by pathological examination. The mass was approximately 0.8 cm × 0.6 cm and located in the muscularis and submucosa of the rectum 8 cm from the anus. CONCLUSIONS: In this case, hemorrhoid is a common disease of rectum and anal canal. However, when it is complicated by another rare disease, the rare one can be easily neglected because of the existence of the common one, especially when the two diseases have similar lesions or symptoms. We suggest that strict physical examination, such as the digital rectal examination in the current case, is critical for correct disease diagnosis.

Sellar and suprasellar granular cell tumor of the neurohypophysis: A rare case report and review of the literature.

Granular cell tumors of the neurohypophysis are rare tumors with a WHO grade of I. Symptomatic tumors are even more rare. In this case, we present a 50-year-old patient with a sellar and suprasellar granular cell tumor of the neurohypophysis, who reported headaches, blurred vision and unsteady gait. CT imaging showed a sellar and suprasellar mass approximately 2.9 cm in diameter with clear boundaries. Histologically, the tumor lacked any obvious atypia and contained densely arranged polygonal tumor cells with abundant granular eosinophilic cytoplasm. Staining for Alpha-1 AntiChymotrypsin (AACT), TTF-1 and PAS was diffusely positive, and S-100 staining was focally positive in the tumor cells. CD34, CK, EMA, GFAP and HMB45 staining were negative. The Ki-67 index was < 1%. According to these findings, the tumor was diagnosed as a symptomatic granular cell tumor of the neurohypophysis. We suggest that identifying the location of the tumor with imaging is helpful for understanding the granular cell tumor of the neurohypophysis. Prompt diagnosis and treatment are critical for patients.

A metastasized hepatocellular carcinoma in the capsule of an undescended testis in the right inguinal area: report of a rare case.

BACKGROUND: Hepatocellular Carcinoma (HCC) is the most common primary carcinoma of the liver, which mainly metastasizes through the portal vein system. CASE PRESENTATION: Here, we report an extremely rare case in which HCC metastasized to the capsule of an undescended testis in the right inguinal area of the patient. A tumor approximately 8.8 × 7.0 cm in size was found in the patient's liver during a health check-up. Initially, it was considered a metastatic tumor because the patient was found to have cryptorchidism, which had been left untreated before he presented to our hospital. The patient underwent a radical orchiectomy via inguinal approach, and the resected testis in the right inguinal region was examined via microscopy. The cancer cells were arranged in nests and showed abundant red or clear cytoplasm and marked nuclear atypia. Immunohistochemical staining showed that the tumor cells were positive for CK, CK8/18, AFP, hepatocyte, GCP3, but negative for PLAP, CD10, CD30, CD34, and vimentin. CONCLUSION: According to these findings, the tumor in the inguinal region was considered a metastatic HCC arising from the liver, rather than a seminoma that had originated in the undescended testis. We suggest that during the diagnosis of malignancies, metastatic tumors should always be considered in the differential diagnosis even if the original presentation is at rare metastatic sites or concurrent with other disease(s).

Kctd20 promotes the development of non-small cell lung cancer through activating Fak/AKT pathway and predicts poor overall survival of patients.

Kctd20 (potassium channel tetramerization protein domain containing 20) is a positive regulator of Akt signaling. However, the role of Kctd20 during the course of tumorigenesis and development is unclear. Using immunohistochemistry, we demonstrated that, in non-small cell lung cancer (NSCLC) patients, Kctd20 protein expression significantly correlates with advanced TNM stage (P < 0.001), positive status for regional lymph node metastasis (P = 0.019), and poor overall survival (P = 0.013). Proliferation and invasion assays showed that Kctd20 dramatically promotes the proliferation and invasion of NSCLC cells (P = 0.007 and P < 0.001, respectively). Subsequent Western Blot and qPCR experiments revealed an upregulation of Cyclin D1 and downregulation of E-cadherin in Kctd20-overexpressing cells. After depleting Kctd20, downregulaton of Cyclin D1, and upegulation of E-cadherin was observed. After overexpressing Kctd20, the levels of phosphorylated Fak (Tyr397) and Akt (Thr308) increased, while after transfection with Kctd20-siRNA these phosporylated proteins were downregulated. Moreover, in Kctd20-overexpressing cells, treatment with an Akt inhibitor reduced expression of p-Akt and Cyclin D1, enhanced E-cadherin expression, and did not impact p-Fak levels. When Kctd20-overexpressing cells were treated with a Fak inhibitor, the same effects were seen, and the level of p-Akt was reduced. Our results suggest that Kctd20 impacts proliferation and invasion of NSCLC through enhancing Fak (Tyr397) and Akt (Thr 308) phosphorylation. Kctd20 may predict prognosis and be targeted therapeutically in NSCLC.

Lasp2 enhances tumor invasion via facilitating phosphorylation of FAK and predicts poor overall survival of non-small cell lung cancer patients.

Lasp2, as well as Lasp1, is a member of the LIM-protein subfamily of the nebulin group characterized by the combined presence of LIM and SH3 domains. Lasp1 and Lasp2 are highly conserved in their LIM, nebulin-like, and SH3 domains but differ significantly at their linker regions. Lasp1 had been described as an oncogenic protein that was highly expressed in diverse cancer types and facilitated tumor proliferation, invasion, and metastasis process. However, unlike Lasp1, little is known about the functions of Lasp2. In the present study, using immunohistochemistry, we found that Lasp2 expression was significantly correlated with histological type (P = 0.012), advanced TNM stage (P = 0.024), positive regional lymph node metastasis (P = 0.035), and poor overall survival (P = 0.001). Would healing assay and transwell assay results indicated that Lasp2 promoted tumor migration and invasion in NSCLC cells. Furthermore, Lasp2 facilitated Snail expression and inhibited Zo-1. The levels of phosphorylated FAK (Tyr397 and Tyr925) were obviously increased after overexpressing Lasp2 and were downregulated by transfecting Lasp2-siRNA. FAK inhibitor counteracted upregulating Snail expression and downregulating of Zo-1 expression induced by Lasp2 overexpression. Taken together, Lasp2 may facilitate tumor migration and invasion of NSCLCs through FAK-Snail/Zo-1 signaling pathway. Lasp2 may be a potential prognostic predictor of NSCLC patients.

Noxin promotes proliferation of breast cancer cells via P38-ATF2 signaling pathway.

Noxin (also called chromosome 11 open reading frame 82 or DNA damage-induced apoptosis suppressor) is associated with anti-apoptosis and cell proliferation in response to stress signals. However, to our knowledge, the role of Noxin in regulating cell proliferation is still controversial and there are no reports of the function and clinicopathological association in breast cancer. In this study, immunohistochemistry results showed that Noxin expression was significantly correlated with advanced tumor-node-metastasis stage ( p = 0.027), positive regional lymph node metastasis ( p = 0.002), and poor overall survival ( p = 0.002). Proliferation assay results showed that Noxin obviously promoted the ability of proliferation of normal breast cells. Subsequent western blot results revealed that Cyclin D1 and Cyclin E1 were upregulated by overexpressing Noxin, whereas Cyclin D1 and Cyclin E1 were downregulated after depleting Noxin. The levels of phosphorylated P38 and activating transcription factor 2 were obviously increased after overexpressing Noxin, and their expression was downregulated accordingly by transfecting Noxin-small interfering RNA. Moreover, P38 inhibitor counteracted the elevating expression of phosphorylated activating transcription factor 2, Cyclin D1, and Cyclin E1 induced by Noxin overexpression and thereby reversed the effect of Noxin overexpression on facilitating cell growth. Taken together, our studies indicated that Noxin was overexpressed in breast cancer and its positive expression was significantly correlated with advance tumor-node-metastasis stage, positive lymph node metastasis, and poor prognosis. Noxin facilitated the expression of Cyclin D1 and Cyclin E1 through activating P38-activating transcription factor 2 signaling pathway, thus enhanced cell growth of breast cancer.

Zbed3 contributes to malignant phenotype of lung cancer via regulating ß-catenin and P120-catenin 1.

Our previous studies indicate that abnormal expression of several Wnt signaling molecules including Axin, Dvl and ß-catenin are involved in proliferation, invasion and metastasis of lung cancer. Zbed3 was found to inhibit function of Axin-GSK3ß complex and thus lead to accumulation of ß-catenin in NIH3T3 and HEK293T cells. However its function in malignant tumors is largely unknown. Here we investigate the clinico-pathological significance of Zbed3 expression and its function in non-small cell lung cancer. We use immunohistochemistry and Western blotting to examine Zbed3 expression in non-small cell lung cancer and lung tissues. Transfection of siRNA and plasmid was used to study the function of Zbed3 in lung cancer cells in vitro. We found Zbed3 expression was elevated in cancer tissues compared to normal lung tissues. Increased Zbed3 expression is significantly associated with lymph node metastasis, advanced TNM stages, higher Ki67 status and patients' poor clinical outcome. Higher Zbed3 expression was also found in lung cancer cell lines compared to bronchial epithelial cell line HBE. Downregulation of Zbed3 by siRNA significantly inhibits cancer cell proliferation and invasion in vitro. Downregulation of Zbed3 also significantly inhibits expression of ß-catenin, downstream molecules of Wnt signaling and P120ctn-1 in lung cancer cells. These results suggest that Zbed3 may contribute to lung cancer cell invasion through regulating ß-catenin and p120ctn-1 and may be a promissing cancer marker in non-small cell lung cancer.

A novel biomarker C6orf106 promotes the malignant progression of breast cancer.

C6orf106 (chromosome 6 open reading frame 106) is a recently discovered protein encoded by the 6th chromosome. Though many proteins encoded by chromosome 6 are reportedly related to cancer, schizophrenia, autoimmunity and many other diseases, the function of C6orf106 was not well demonstrated so far. As measured by immunohistochemical staining, C6orf106 was positive in normal breast duct myoepithelial cells (92.31 %, 72/78), but negative in normal breast duct glandular epithelial cells (3.85 %, 3/78). In breast ductal carcinoma in situ, C6orf106 showed weakly or moderately positive (77.97 %, 46/59), but it was significantly strongly positive in invasive ductal carcinoma (79.57 %, 148/186). The expression intensity of C6orf106 seemed increased significantly along with the malignancy of breast cancer (p < 0.001). Additionally, C6orf106 expression was significantly correlated with TNM stage (p = 0.001 and p = 0.004) and lymph node metastasis (p = 0.018 and p = 0.025) of the overall and the triple-negative breast cancer, respectively. Consistently, we found that the interference of C6orf106 was able to inhibit cell proliferation and invasion of two triple-negative breast cancer cell lines, MDA-MB-231 and BT-549, accompanied by the decrease of cyclin A2, cyclin B1, c-myc, and N-cadherin and the increase of E-cadherin. Collectively, these results indicate that C6orf106 may promote tumor progression in the invasive breast cancer, particularly in triple-negative breast cancer, and C6orf106 might serve as a novel therapeutic target of breast cancer, especially for triple-negative breast cancer.

ARMc8 indicates aggressive colon cancers and promotes invasiveness and migration of colon cancer cells.

Recent studies have implicated ARMc8 in promoting tumor formation in non-small cell lung cancer and breast cancer; however, so far, no studies have revealed the expression pattern or cellular function of ARMc8 in colon cancer. In this study, we used immunohistochemical staining to measure ARMc8 expression in 206 cases of colon cancer and matched adjacent normal colon tissue. Clinically important behaviors of cells, including invasiveness and migration, were evaluated after upregulation of ARMc8 expression in HT29 cells through gene transfection or downregulation of expression in LoVo cells using RNAi. We found that ARMc8 was primarily located in the membrane and cytoplasm of tumor cells, and its expression level was significantly higher in colon cancer in comparison to that in the adjacent normal colon tissues (p < 0.001). ARMc8 expression was closely related to TNM stage (p = 0.006), lymph node metastasis (p = 0.001), and poor prognosis (p = 0.002) of colon cancer. The invasiveness and migration capacity of HT29 cells transfected with ARMc8 were significantly greater than those of control cells (p < 0.001), while ARMc8 siRNA treatment significantly reduced cell invasion and migration in LoVo cells (p < 0.001). Furthermore, we demonstrated that ARMc8 could upregulate the expression of MMP7 and snail and downregulate the expression of p120ctn and α-catenin. Therefore, ARMc8 probably enhanced invasiveness and metastatic capacity by affecting these tumor-associated factors, thereby playing a role in enhancing the tumorigenicity of colon cancer cells. ARMc8 is likely to become a potential therapeutic target for colon cancer.

DIXDC1 increases the invasion and migration ability of non-small-cell lung cancer cells via the PI3K-AKT/AP-1 pathway.

DIX domain containing 1 (DIXDC1), is a human homolog of Ccd1, a recently identified DIX domain containing protein in zebrafish. DIXDC1 protein was detected in human colorectal adenocarcinoma tissues and was found to be correlated with a high cell proliferation index. We demonstrated DIXDC1 overexpression in 55% (92/167) of non-small cell lung cancer (NSCLC) cases, compared to adjacent noncancerous lung tissues (P < 0.01). Overexpression of DIXDC1 was associated with lymph node metastasis and more advanced TNM stage (P < 0.001 and P = 0.001, respectively). Kaplan-Meier survival curves and log-rank testing indicated that overexpression of DIXDC1 correlated with worse overall survival in NSCLC (P = 0.031). DIXDC1 was more abundant in seven NSCLC lines than the bronchial cell line HBE, and modulation of its expression regulated AP-1 activity; MMP2, MMP7, and MMP9 protein and mRNA; and invasion ability. Metalloproteinase induction was reversed by PI3K/AKT and AP-1 inhibition. These results suggest DIXDC1 is associated with stage and prognosis in NSCLC, and may promote invasion and migration through PI3K-AKT/AP-1-dependent activation of metalloproteinases.

ASAP3 expression in non-small cell lung cancer: association with cancer development and patients' clinical outcome.

ASAP3 belongs to Arf-specific GTPase-activating proteins which regulate Arfs by stimulating their intrinsic GTP hydrolysis. ASAP3 expression and the clinical significance in malignant tumors are largely unknown. In this study, we examined ASAP3 expression in non-small cell lung cancer (NSCLC) to find out its clinicopathological significance. Immunohistochemistry shows elevated expression of ASAP3 in cancer tissues (54.8 % (57/104)) compared to normal lung tissues (18.0 % (9/50)) (p < 0.05). Increased ASAP3 expression was associated with poor differentiation, lymph node metastasis, and advanced TNM stages in NSCLC (p < 0.05). Survival analysis reveals that ASAP3 expression contributes to patients' poor clinical outcome (p < 0.05). We also examined ASAP3 expression in several lung cancer cell lines using Western blotting. We downregulated ASAP3 expression in LTE cell which has a relative high level of ASAP3 expression using siRNA and found that reduced ASAP3 leads to significant inhibition of cancer cell invasion (p < 0.05). These data indicate that ASAP3 is elevated in NSCLC and may contribute to cancer development and patients' poor clinical outcome, which is possibly due to its critical roles in regulating cancer invasion.