Semaphorin 4C regulates ovarian steroidogenesis through RHOA/ROCK1-mediated actin cytoskeleton rearrangement.

Semaphorins are a family of evolutionarily conserved morphogenetic molecules that were initially found to be associated with axonal guidance. Semaphorin 4C (Sema4C), a member of the fourth subfamily of semaphorins, has been demonstrated to play multifaceted and important roles in organ development, immune regulation, tumor growth, and metastasis. However, it is completely unknown whether Sema4C is involved in the regulation of ovarian function. We found that Sema4C was widely expressed in the stroma, follicles, and corpus luteum of mouse ovaries, and its expression was decreased at distinct foci in ovaries of mice of mid-to-advanced reproductive age. Inhibition of Sema4C by the ovarian intrabursal administration of recombinant adeno-associated virus-shRNA significantly reduced oestradiol, progesterone, and testosterone levels in vivo. Transcriptome sequencing analysis showed changes in pathways related to ovarian steroidogenesis and the actin cytoskeleton. Similarly, knockdown of Sema4C by siRNA interference in mouse primary ovarian granulosa cells or thecal interstitial cells significantly suppressed ovarian steroidogenesis and led to actin cytoskeleton disorganization. Importantly, the cytoskeleton-related pathway RHOA/ROCK1 was simultaneously inhibited after the downregulation of Sema4C. Furthermore, treatment with a ROCK1 agonist after siRNA interference stabilized the actin cytoskeleton and reversed the inhibitory effect on steroid hormones described above. In conclusion, Sema4C may play an important role in ovarian steroidogenesis through regulation of the actin cytoskeleton via the RHOA/ROCK1 signaling pathway. These findings shed new light on the identification of dominant factors involved in the endocrine physiology of female reproduction.

Suppression of SEMA6C promotes preantral follicles atresia with decreased cell junctions in mice ovaries.

Mammalian oocytes go through a long and complex developmental process, while acquiring the competencies that are required for fertilization and embryogenesis. Recent studies revealed that the communication between oocytes and granulosa cells (GCs) is a critical process for female follicle development. In the current study, we aimed to study whether and how semaphorin 6C (Sema6c) regulated the cell junctions between oocytes and GCs in mice preantral follicles. The attenuation of SEMA6C expression by siRNA decreased the cell-cell junctions and accelerated follicle atresia in vitro. PI3K-AKT pathway was activated when SEMA6C expression was downregulated. And the LY294002, a PI3K inhibitor, could reverse the effect of low SEMA6C expression on cell junctions in preantral follicles. Our findings revealed that Sema6c was involved in follicle development, and the suppression of SEMA6C led to cell junction defection by activating the PI3K/AKT pathway, which might also provide valuable information for understanding premature ovarian failure and ovarian aging.

Correction to: Plexin-B1 silencing inhibits ovarian cancer cell migration and invasion.

Following publication of the original article [1], the authors reported the following error is the article.

Smad4 is required for the development of cardiac and skeletal muscle in zebrafish.

Transforming growth factor-beta (TGF-beta) regulates cellular functions and plays key roles in development and carcinogenesis. Smad4 is the central intracellular mediator of TGF-beta signaling and plays crucial roles in tissue regeneration, cell differentiation, embryonic development, regulation of the immune system and tumor progression. To clarify the role of smad4 in development, we examined both the pattern of smad4 expression in zebrafish embryos and the effect of smad4 suppression on embryonic development using smad4-specific antisense morpholino-oligonucleotides. We show that smad4 is expressed in zebrafish embryos at all developmental stages examined and that embryonic knockdown of smad4 results in pericardial edema, decreased heartbeat and defects in the trunk structure. Additionally, these phenotypes were associated with abnormal expression of the two heart-chamber markers, cmlc2 and vmhc, as well as abnormal expression of three makers of myogenic terminal differentiation, mylz2, smyhc1 and mck. Furthermore, a notable increase in apoptosis was apparent in the smad4 knockdown embryos, while no obvious reduction in cell proliferation was observed. Collectively, these data suggest that smad4 plays an important role in heart and skeletal muscle development.

Safety of ovarian preservation in women with stage I and II cervical adenocarcinoma: a retrospective study and meta-analysis.

BACKGROUND: The safety of ovarian preservation remains uncertain in women with cervical adenocarcinoma and significant risk factors for ovarian metastases vary among different studies. OBJECTIVE: We sought to evaluate the impact of ovarian preservation on prognosis in women with cervical adenocarcinoma and to assess clinical factors associated with ovarian metastases. STUDY DESIGN: A retrospective study of 194 women with cervical adenocarcinoma was conducted and 159 women were followed up until the end of the study. To compare the impact of ovarian preservation on prognosis, women with successful follow-up were studied, including 33 women with ovarian preservation and 126 women who underwent bilateral salpingo-oophorectomy. For women who underwent radical hysterectomy, pelvic lymphadenectomy, and bilateral salpingo-oophorectomy, the risk factors for ovarian metastases were identified. A meta-analysis of the literature was carried out to further validate the findings. RESULTS: There was no significant difference in survival between women with bilateral salpingo-oophorectomy and ovarian preservation (P = .423 for disease-free survival; P = .330 for overall survival). Tumor size (>4 cm), deep cervical stromal invasion, and lymph node metastasis were significant independent prognostic factors related to poor disease-free survival, and lymph node metastasis was significantly associated with overall survival. Of 153 women with cervical adenocarcinoma who underwent bilateral salpingo-oophorectomy, a significant difference was found in the relationship between ovarian metastasis and deep cervical stromal invasion, lymph node metastasis, and parametrial invasion. The meta-analysis showed that clinical stage IIB vs I-IIA (odds ratio, 4.64; 95% confidence interval, 2.11-10.23), deep stromal invasion (odds ratio, 10.63; 95% confidence interval, 3.12-36.02), lymph node metastasis (odds ratio, 8.54; 95% confidence interval, 4.15-17.57), corpus uteri invasion (odds ratio, 7.39; 95% confidence interval, 3.69-14.78), and parametrial invasion (odds ratio, 9.72; 95% confidence interval, 4.67-20.22) were significantly related to ovarian metastasis. CONCLUSION: Ovarian preservation has no effect on prognosis in women with early-stage cervical adenocarcinoma. Risk factors for ovarian metastases were stage IIB, deep cervical stromal invasion, lymph node metastasis, corpus uteri invasion, and parametrial invasion. In women with early-stage cervical adenocarcinoma without these risk factors, ovarian conservation can be considered.

Unilateral Genital Tract Obstruction with Ipsilateral Renal Anomaly Syndrome: Classification, Clinical Manifestations, and Precise Diagnose.

Purpose: To recommend the classification of unilateral genital tract obstruction with ipsilateral renal anomaly (UGTOIRA) syndrome into five types based on the site of obstruction, and to analyze the clinical manifestations and precise diagnosis of the syndrome. Methods: The data, including demographic characteristics, symptoms, and precise diagnoses from 59 patients over the last decade, were retrospectively analyzed. Data analysis was conducted using the statistical software package SPSS 26.0. Results: All 59 patients diagnosed with UGTOIRA syndrome were classified into five types based on the site of obstruction: Type I (vaginal obstruction) (45, 76.3%), Type II (cervicovaginal obstruction) (7, 11.9%), Type III (cervical obstruction) (3, 5.1%), Type IV (unilateral partial cervical aplasia) (3, 5.1%), and Type V (Unilateral isthmus atresia) (1, 1.7%). Of these cases, there were 34 cases (57.6%) with communication and 25 cases (42.4%) without communication between the left and right genital tracts. The chief complaints included dysmenorrhea alone in 28 cases (47.5%), dysmenorrhea accompanied by blood dripping after menstruation in 12 cases (20.3%), blood dripping after menstruation alone in 14 cases (23.7%), purulent vaginal secretions in one case (1.7%), vaginal pain in one case (1.7%), irregular menstruation in one case (l.7%), and infertility in two cases (3.4%). The precise diagnostic criteria include the affected side, abnormalities in the kidney and ureter, the site of obstruction, the location of blood accumulation, the size of the ipsilateral genital tract, whether there is communication and its site, the type based on the site of obstruction, and the presence and type of complications. Conclusion: This classification of UGTOIRA syndrome encompasses the anatomical features of all cases reported in our study. Only by fully understanding the anatomical characteristics of this syndrome and identifying its clinical manifestations can clinicians make precise diagnoses as early as possible and provide individualized management.

Sema4d is required for the development of the hindbrain boundary and skeletal muscle in zebrafish.

Semaphorin4d (SEMA4D), also known as CD100, an oligodendrocyte secreted R-Ras GTPase-activating protein (GAP), affecting axonal growth is involved in a range of processes including cell adhesion, motility, angiogenesis, immune responses and tumour progression. However, its actual physiological mechanisms and its role in development remain unclear. This study has focused on the role of sema4d in the development and expression patterns in zebrafish embryos and the effect of its suppression on development using sema4d-specific antisense morpholino-oligonucleotides. In this study the knockdown of sema4d, expressed at all developmental stages, lead to defects in the hindbrain and trunk structure of zebrafish embryos. In addition, these phenotypes appeared to be associated with the abnormal expression of three hindbrain rhombomere boundary markers, wnt1, epha4a and foxb1.2, and two myogenic regulatory factors, myod and myog. Further, a notable increase of cell apoptosis appeared in the sema4d knockdown embryos, while no obvious reduction in cell proliferation was observed. Collectively, these data suggest that sema4d plays an important role in the development of the hindbrain and skeletal muscle.

DT390-triTMTP1, a novel fusion protein of diphtheria toxin with tandem repeat TMTP1 peptide, preferentially targets metastatic tumors.

Peptide-based therapies have emerged as one of the most promising therapeutics strategy in cancer-targeted therapy. Using our laboratory newly identified peptide TMTP1 and diphtheria toxin, we developed a new fusion protein that showed remarkable ability to target highly metastatic tumors. Fusion protein toxins were generated by fusing the first 390 amino acids of diphtheria toxin [truncated diphtheria toxin (DT390)] to different repeats of peptide TMTP1 (DT390-TMTP1, DT390-biTMTP1, and DT390-triTMTP1). Efficacies of the recombinant fusion proteins on tumor growth and metastasis were evaluated in vitro and in vivo. DT390-triTMTP1 showed the most powerful toxicity against cancer, which led to tumor growth retardation or regression and prolonged survival of human prostate cancer PC-3M-1E8 subcutaneously bearing or gastric cancer MKN-45 orthotopic nude mice. Increased TUNEL and caspase-3 staining and reduced ki67 staining in tumor cells suggested that the anticancer effects of DT390-triTMTP1 were through selectively inducing apoptosis and inhibiting proliferation of cancer cells. In a murine model of human orthotopic gastric carcinoma, DT390-biTMTP1 significantly inhibited metastases to liver and spleen, while DT390-triTMTP1 not only totally suppressed metastasis but also reduced primary tumors by 66.6%. In the biodistribution test, DT390-triTMTP1 was observed to home to tumor tissue rapidly and lasted over 48 h, with only a transient appearance in liver and kidney immediately after injection. Thus, our present study provided a novel recombinant fusion protein DT390-triTMTP1 with preferential targeting and high cytotoxicity, which may be a promising strategy for the targeted therapy of cancer metastasis.

Diverse ultrasound image features of unilateral genital tract obstruction with ipsilateral renal anomaly syndrome on genitourinary system segmental sequential ultrasound screening and the accuracy of ultrasonic diagnosis.

Background: Unilateral genital tract obstruction with ipsilateral renal anomaly (UGTOIRA) syndrome is a rare congenital urogenital anomaly, characterized by different combinations of uterine abnormalities, unilateral cervical-vaginal obstruction, and ipsilateral renal abnormalities. Timely and correct diagnosis is critical. In this study, we analyzed the diverse ultrasound image features of UGTOIRA syndrome on genitourinary system segmental sequential ultrasound screening (SSUS) and the accuracy of ultrasonic diagnosis. Methods: The data from 59 patients with UGTOIRA syndrome over the last decade were analyzed retrospectively, which included ultrasound presentations and diagnoses of abnormalities of the uterus, cervix, and vagina, as well as the conditions associated with the bilateral fallopian tubes, ovaries, pelvis, kidneys and ureters, bladder, and urethra. Results: All 59 patients (100%) were found to have ipsilateral renal agenesis, and the diagnostic accuracy of ultrasound was 100%. The uterus was correctively diagnosed as complete bicorporal uterus in 42 cases (71.2%), bicorporal septate uterus in 7 cases (11.9%), complete uterus septate in 8 cases (13.6%), partial uterus septate in 1 case (1.7%), and unilateral isthmus atresia in 1 case (1.7%). The cervix was correctively diagnosed as septate cervix in 28 cases (47.5%), double cervix in 17 cases (28.8%), unilateral small cervix in 5 cases (8.5%), unilateral obliterated cervical orifice in 5 cases (8.5%), partial development of the unilateral cervix with a blind end in 3 cases (5.1%), and unilateral completely undeveloped cervix appearing as a normal cervix in 1 case (1.7%). The vagina was correctively diagnosed as oblique vaginal septum (OVS) in 45 cases (76.3%), and normal vagina in 13 cases (22.0%) via preoperative ultrasound. In 1 case (1/59, 1.7%) of high OVS with ipsilateral obliterated external cervical orifice, the OVS was missed by preoperative ultrasound. The ultrasound diagnostic accuracy rates of uterine malformation, cervical malformation, vaginal malformation, hematoma location and volume, uterine communication, and cervical communication were respectively 100%, 100%, 98.3%, 100%, 100%, and 100%. The ultrasonic detection rate for a hole on the OVS was 0%, and the missed diagnosis rate was 100%. Conclusions: SSUS can be used to accurately evaluate uterine, cervical, and vaginal malformation, obstruction site, location and volume of keratocele, cervical or uterine communication, and ovarian endometriosis cyst in patients with UGTOIRA syndrome and ipsilateral urinary system malformation. However, ultrasound is unable to identify a hole on the OVS.

[Expression and clinical significance of Sema4C in esophageal cancer, gastric cancer and rectal cancer].

OBJECTIVE: To explore the expression and clinical significance of signal protein Sema4C in esophageal cancer, gastric cancer and rectal cancer. METHODS: Fifty esophageal cancer, 75 gastric cancer, 50 rectal cancer and 20 corresponding normal mucous membrane specimens, collected during the period of January 2008 to December 2010, were detected with streptavidin-peroxidase immunohistochemistry to detect the expression levels of Sema4C. And the relationships of the Sema4C expression with clinicopathological data was analyzed. RESULTS: The expression levels of Sema4C in three kinds of cancers were significantly higher than the corresponding normal mucous membranes (80.0% (n = 40) vs 20.0% (n = 4), 77.3% (n = 58) vs 25.0% (n = 5), 80.0% (n = 40) vs 15.0% (n = 3), all P = 0.000). Furthermore, the percentage of Sema4C positive cells was significantly higher in carcinoma nests of tumors with lymphatic metastasis than those without (90.3% (n = 28) vs 63.2% (n = 12), 85.0% (n = 51) vs 46.7% (n = 7), 92.0% (n = 23) vs 68.0% (n = 17), P = 0.049, 0.005, 0.034). However, no significant correlations were found between the Sema4C expression with gender, age, location of tumors, types of cancer cells, cell differentiation, tumor size, depth of invasion or tumor stage (all P > 0.05). CONCLUSION: There is a high expression of Sema4C in esophageal cancer, gastric cancer and rectal cancer. And it is strongly correlated with lymphatic metastasis. Thus Sema4C may play critical roles in the invasion and lymphatic metastasis of esophageal cancer, gastric cancer and rectal cancer.

MiR-145 regulates steroidogenesis in mouse primary granulosa cells through targeting Crkl.

AIMS: It has been demonstrated that miR-145 is expressed in primordial follicles and modulates the initiation of primordial follicle development. We aimed to explore the function of miR-145 in mouse granulosa cells (mGCs). MATERIALS AND METHODS: The proliferation and differentiation of GCs were examined via MTT, EDU assay, QRT-PCR, ELISA and electron microscope analysis. The target of miR-145 was determined by bioinformatics analysis and luciferase reporter assay and the molecular mechanisms were examined via western blot and quantitative Real-Time RT-PCR. KEY FINDINGS: We proved that down-regulation of miR-145 could inhibit GCs proliferation and differentiation. In addition, we provided evidence that Crkl was the target gene of miR-145. The miR-145 antagomir caused an increase in Crkl expression and activation of the JNK/p38 MAPK pathway. Overexpression of Crkl with pEGFP-N1-Crkl vector inhibited GCs differentiation and progesterone synthesis as well as activation of the JNK/p38 MAPK pathway. SIGNIFICANCE: Our study shows that miR-145 targets Crkl and through the JNK/p38 MAPK signaling pathway promotes the GCs proliferation, differentiation, and steroidogenesis. MiR-145 may play an important role in the ovarian physiology and pathology.

Plexin-B1 silencing inhibits ovarian cancer cell migration and invasion.

BACKGROUND: Elevated Plexin-B1 expression has been found in diverse human cancers and in non-neoplastic tissues, and it mediates diverse biological and pathological activities. However, whether or not Plexin-B1 expression is involved in human ovarian tumors remains unclear. In the present study, Plexin-B1 expression was explored in benign and malignant human ovarian tumor tissues. In addition, the impact of Plexin-B1 expression on ovarian cancer cell proliferation, migration and invasion were investigated in vitro. METHODS: Plexin-B1 expression was analyzed in normal and benign ovarian tissues and serous ovarian tumors (both borderline and malignant) by immunohistochemical staining, as well as in four human ovarian cancer cell lines (A2780, C13*, SKOV3, and OV2008) by RT-PCR and western blot analyses. Furthermore, endogenous Plexin-B1 expression was suppressed by Plexin-B1 siRNA in SKOV3 cells, which overexpress Plexin-B1. Protein levels of Plexin-B1, AKT and AKTSer473 were examined by western blot analysis. Cell proliferation, migration and invasion were measured with MTT, wound healing and boyden chamber assays, respectively, and the cytoskeleton was monitored via F-actin staining. RESULTS: Expression levels of Plexin-B1 protein were significantly higher in serous ovarian carcinomas than in normal ovaries or benign ovarian neoplasms, and in the former, Plexin-B1 expression was positively correlated with lymphatic metastasis, and the membrane and cytoplasm of cancer cells stained positively. SKOV3 cells displayed the highest Plexin-B1 expression at both the mRNA and protein levels among the four tested human ovarian cancer cell lines and was selected as a cell model for further in vitro experiments. Plexin-B1 siRNA significantly suppressed phosphorylation of AKT at Ser473 in SKOV3 cells, but it did not alter total AKT expression. In addition, silencing of Plexin-B1 in SKOV3 cells inhibited cell migration and invasion and reorganized the cytoskeleton, whereas cell proliferation was not affected. CONCLUSION: Plexin-B1 expression correlates with malignant phenotypes of serous ovarian tumors, probably via phosphorylation of AKT at Ser473, suggesting that Plexin-B1 might be a useful biomarker and/or a novel therapeutic target.

Effect of Mad2 on paclitaxel-induced cell death in ovarian cancer cells.

In this article, the status of spindle assembly checkpoint and the alteration of its major component, Mad2 protein level were examined in A2780 and SKOV3 ovarian cancer cell lines. Recombinant eukaryotic expression plasmid pEGFP-Mad2 was transfected into paclitaxel-resistant SKOV3 cells and Mad2 protein was knocked down by Mad2-specific siRNA in paclitaxel-sensitive A2780 cells. Then the expression level of Mad2 gene was detected by Western blotting. Flow cytometry revealed that SKOV3 cells were not fully arrested in G(2)/M phase in contrast to A2780 cells in the presence of paclitaxel. However, paclitaxel sensitivity assay showed that sensitivity to paclitaxel was reversed after the transfection in both cell lines in terms of number of cells arrested at G(2)/M phase and the expression of Bcl-2 was significantly changed. These results suggest that weakened spindle checkpoint with reduced expression of Mad2 is associated with resistance to paclitaxel in ovarian cells and Bcl-2 may be involved in this process.

Identification of novel epithelial ovarian cancer biomarkers by cross-laboratory microarray analysis.

The purpose of this study was to pool information in epithelial ovarian cancer by combining studies using Affymetrix expression microarray datasets made at different laboratories to identify novel biomarkers. Epithelial microarray expression information across laboratories was screened and combined after preprocessing raw microarray data, then ANOVA and unpaired T test statistical analysis was performed for identifying differentially expressed genes (DEGs), followed by clustering and pathway analysis for these DEGs. In this work, we performed a combination analysis on microarrays from three different laboratories using gene expression data on ovarian cancer and obtained a list of differential expression profiles identified as potential candidate in aggressiveness of ovarian cancer. The clustering and pathway analysis explored the different molecular basis of different ovarian cancer stages and potential important regulatory pathways in ovarian cancer development. Our results showed that combination of microarray data from different laboratories in the same platforms may overcome biases derived from probe design and technical features, thereby accelerating the identification of trustworthy DEGs, and demonstrating the advantage of integrative analysis in gene expression studies on epithelial ovarian cancer research.

Effect of spindle checkpoint on Akt2-mediated paclitaxel-resistance in A2780 ovarian cancer cells.

Recent evidence has suggested that Akt2 plays an important role in the protection of cells from paclitaxel (PTX)-induced apoptosis and control of the cell cycle. In addition, some scholars suggested that the PTX sensitivity depends on a functional spindle assembly checkpoint. In the present study, we investigated the role of the Akt2/Bub1 cross-talking in apoptosis and cell cycle after exposure of the A2780 ovarian cancer cells to paclitaxel (PTX). Recombinant expression plasmid WT-Akt2 was transfected into A2780 cells by lipofectamine2000, and then the expression level of Akt2 gene was detected by using RT-PCR and Western blotting. Cell apoptosis and cell cycle were detected by flow cytometry and Hoechst 33342 staining after treatment with PTX. Moreover, we compared the expression level of Bub1 in different groups by Western blotting. Our study showed that up-regulation of Akt2 contributed to A2780 ovarian cancer cells overriding PTX-induced G(2)/M arrest, and inhibited Bub1 expression. Our findings might shed light on the molecular mechanism of PTX-induced resistance in ovarian cancer and help develop novel anti-neoplastic strategies.

Semaphorin 4C Promotes Macrophage Recruitment and Angiogenesis in Breast Cancer.

Semaphorins are a large family of evolutionarily conserved morphogenetic molecules that are associated with repelling axonal guidance. Intriguingly, recent researches indicate that semaphorins are involved in cancer progression. Semaphorin 4C (SEMA4C) has long been considered a neuronal migration gene, but we detected that it is also highly expressed in many malignant human cancers. During an investigation of subcutaneous tumor models, we found that SEMA4C expression promoted tumor growth and progression. We discovered that SEMA4C was involved in maintaining tumor cell self-renewal, likely by regulating the p53 pathway. Inhibiting the expression of endogenous SEMA4C in tumor cells impaired growth and induced senescence and cell-cycle arrest in the G2-phase. In addition, we found that SEMA4C induced the production of angiogenin and colony-stimulating factor-1 (CSF-1) in tumor cells by activating the NF-κB pathway in a plexinB2-dependent manner. In conclusion, SEMA4C expression in breast cancer cells promotes cancer cell proliferation, macrophage recruitment, and angiogenesis. Thus, inhibition of SEMA4C activity may be a novel therapeutic strategy for human breast cancer. IMPLICATIONS: In breast cancer, therapeutic targeting of the SEMA4C pathway may prevent tumor growth, angiogenesis, metastasis, and progression.

The role of the ATM/Chk/P53 pathway in mediating DNA damage in hand-foot syndrome induced by PLD.

Pegylated liposomal doxorubicin (PLD) has been approved to treat patients with various types of cancers because it rarely caused side effects, such as cardiotoxicity, in comparison to doxorubicin, but it frequently results in hand-foot syndrome (HFS). This may affect the quality of life and require a reduction in the PLD dose. The pathophysiology of HFS was not well understood. This study was aimed at exploring the mechanism of HFS induced by PLD. We compared the effects of different doses of PLD on the proliferation inhibition and apoptosis in vitro in HaCaT cells and analyzed the skin changes and skin cell DNA damage in vivo using a zebrafish model. The results suggested that very low doses of PLD show a proliferation inhibition (cell cycle arrest at G2/M phase) and an apoptosis phenotype characterized by the ATM/Chk/P53 pathway that mediates DNA damage in vitro in HaCaT cells. In addition, PLD enhanced zebrafish skin pigmentation from the head to the trunk and induced DNA damage (phospho-H2AX staining) and cell death in the skin of zebrafish. The results of the present study suggested potential applications to provide a better understanding of the apoptosis of PLD-treated skin cells and described a simple methodology for detecting a PLD-induced DNA damage response in zebrafish, which may be helpful in preventing and treating HFS.

Tumor-associated Lymphatic Endothelial Cells Promote Lymphatic Metastasis By Highly Expressing and Secreting SEMA4C.

PURPOSE: Lymphatic vessels are mainly regarded as passive conduits for the dissemination of cancer cells. In this study, we investigate whether and how the tumor-associated lymphatic vessels may play an active role in tumor metastasis. EXPERIMENTAL DESIGN: In situ laser capture microdissection of lymphatic vessels followed by cDNA microarray analysis was used to determine the expression profiling of lymphatic endothelial cells (LEC). Gene expression levels and activity of signaling pathways were measured by real-time RT-PCR, ELISA, or immunoblotting. Lymphangiogenesis was assessed by IHC. Lymph node metastasis was measured using fluorescence imaging. The effects of SEMA4C on lymphangiogenesis in vitro were evaluated using migration assay and tube-formation assay of LECs. RESULTS: Tumor-associated LECs are molecularly and functionally different from their normal counterparts. In addition to expressing high levels of membrane-bound SEMA4C, tumor-associated LECs also produced soluble SEMA4C (sSEMA4C). Increased serum sSEMA4C was detected in patients with breast cancer and cervical cancer. Patients with metastasis had much higher levels of serum sSEMA4C. sSEMA4C promoted lymphangiogenesis by activating PlexinB2-ERBB2 signaling in LECs, and promoted the proliferation and migration of tumor cells by activating PlexinB2-MET signaling, thus promoting lymphatic metastasis. Although the SEMA4C signaling pathways differ between LECs and tumor cells, RHOA activation was necessary for the effects of SEMA4C in both types of cells. CONCLUSIONS: Tumor-associated LECs produce sSEMA4C to promote lymphatic metastasis of tumors. Our results suggest that SEMA4C and RHOA might be potential therapeutic targets, and that higher serum sSEMA4C could be a marker for breast cancer and cervical cancer. Clin Cancer Res; 23(1); 214-24. ©2016 AACR.

Anti-tumor effects of the peptide TMTP1-GG-D(KLAKLAK)(2) on highly metastatic cancers.

The treatment of cancer such as oligonucleotides or peptides requires efficient delivery systems. A novel peptide, TMTP1, previously derived and identified in our laboratory showed remarkable ability to target highly metastatic tumors both in vitro and in vivo, even at the early stage of occult metastasis foci. TMTP1 moderately inhibited tumor cell viability, although not enough to deem it an efficient killer of tumor cells. In this study, we sought to enhance the anti-tumor activity of TMTP1. To do this, we fused it to an antimicrobial peptide, (D)(KLAKLAK)(2), and termed the resulting peptide TMTP1-DKK. We found that TMTP1-DKK could trigger rapid apoptosis in human prostate and gastric cancer cells through both the mitochondrial-induced apoptosis pathway and the death receptor pathway. Furthermore, direct injection of TMTP1-DKK into mice with prostate and gastric xenograft cancers resulted in reduction of tumor volumes and a significant delay in tumor progression and metastasis in vivo. These results suggest that TMTP1-DKK may serve as a powerful therapeutic agent for metastatic tumors.