MARCKS contributes to stromal cancer-associated fibroblast activation and facilitates ovarian cancer metastasis

The Cancer Genome Atlas network has revealed that the 'mesenchymal' epithelial ovarian cancer (EOC) subtype represents the poorest outcome, indicating a crucial role of stromal cancer-associated fibroblasts (CAFs) in disease progression. The cooperative role of CAFs in EOC metastasis has long been recognized, but the mechanisms of stromal CAFs activation are still obscure. Therefore, we carried out an integrative analysis to identify the regulator genes that are responsible for CAFs activation in microdissected tumor stroma profiles. Here, we determined that myristoylated alanine-rich C-kinase substrate (MARCKS) was highly expressed in ovarian stroma, and was required for the differentiation and tumor promoting function of CAFs. Suppression of MARCKS resulted in the loss of CAF features, and diminished role of CAFs in supporting tumor cell growth in 3D organotypic cultures and in murine xenograft model. Mechanistically, we found that MARCKS maintained CAF activation through suppression of cellular senescence and activation of the AKT/Twist1 signaling. Moreover, high MARCKS expression was associated with poor patient survival in EOC. Collectively, our findings identify the potential of MARCKS inhibition as a novel stroma-oriented therapy in EOC.

Development and validation of a surgical-pathologic staging and scoring system for cervical cancer

Background

Most cervical cancer patients worldwide receive surgical treatments, and yet the current International Federation of Gynecology and Obstetrics (FIGO) staging system do not consider surgical-pathologic data. We propose a more comprehensive and prognostically valuable surgical-pathologic staging and scoring system (SPSs).

Methods

Records from 4,220 eligible cervical cancer cases (Cohort 1) were screened for surgical-pathologic risk factors. We constructed a surgical-pathologic staging and SPSs, which was subsequently validated in a prospective study of 1,104 cervical cancer patients (Cohort 2).

Results

In Cohort 1, seven independent risk factors were associated with patient outcome: lymph node metastasis (LNM), parametrial involvement, histological type, grade, tumor size, stromal invasion, and lymph-vascular space invasion (LVSI). The FIGO staging system was revised and expanded into a surgical-pathologic staging system by including additional criteria of LNM, stromal invasion, and LVSI. LNM was subdivided into three categories based on number and location of metastases. Inclusion of all seven prognostic risk factors improves practical applicability. Patients were stratified into three SPSs risk categories: zero-, low-, and high-score with scores of 0, 1 to 3, and ≥4 (P=1.08E-45; P=6.15E-55). In Cohort 2, 5-year overall survival (OS) and disease-free survival (DFS) outcomes decreased with increased SPSs scores (P=9.04E-15; P=3.23E-16), validating the approach. Surgical-pathologic staging and SPSs show greater homogeneity and discriminatory utility than FIGO staging.

Conclusions

Surgical-pathologic staging and SPSs improve characterization of tumor severity and disease invasion, which may more accurately predict outcome and guide postoperative therapy.

[Platelet to lymphocyte ratio in peripheral blood and body mass index: novel independent prognostic factors in patients with melanoma]

Objective: To investigate whether platelet to lymphocyte ratio (PLR) in peripheral blood and body mass index (BMI) can be independent prognostic factors in patients with melanoma. Methods: Clinical date of 140 patients with melanoma in the Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer Hospital from January 1, 2010 to December 31, 2015 were analyzed retrospectively.Receiver operating characteristic (ROC) curve was performed the optimal cut-off value for PLR.The 140 patients were divided into high PLR group and low PLR group.According to "Guidelines for prevention and control of overweight and obesity in Chinese adults" , the patients were divided into high BMI group and low BMI group.The relationship between PLR, BMI with overall survival (OS), progression free survival (PFS) and disease free survival (DFS) were analyzed.The Kaplan-Meier method and Log rank test was used for univariate survival analysis and Cox proportional hazards regression model for multivariate analysis. Results: The optimal cut-off value of PLR determined by ROC curve was PLR=120.15, and BMI threshold was 24.Univariate survival analysis showed that PLR, BMI and clinical stage were the factors affecting the OS in patients (P<0.05). The median survival time (MST) was 21 months in the whole group and 17 months in the high PLR group, 34 months in the low PLR group, respectively; the MST in the high and low BMI group were 29 months and 13 months, respectively.The difference was statistically significant (P<0.05). The effects of PLR and BMI on PFS and DFS were not statistically significant.Cox multivariate analysis showed that PLR, BMI and clinical stage were independent prognostic factors of OS (P<0.05). And BMI was the only independent protective factor for OS, the risk of death decreased by 0.611 times, with each unit increased for BMI.Clinical subgroup analysis showed that PLR also was risk factor to the prognosis of patients with stage Ⅱ, Ⅲ, and Ⅳ (P<0.05). Conclusions: PLR is an independent prognostic risk factor for patients with melanoma, and BMI is an independent protective factor.PLR and BMI are important factors in prognostic evaluation of melanoma.

Dicer reprograms stromal fibroblasts to a pro-inflammatory and tumor-promoting phenotype in ovarian cancer

Inflammation and host stromal activation contribute significantly to ovarian cancer (OC) initiation and malignant progression. However, the complex reciprocal interactions between them are largely unknown. Here, we discovered that the tumor suppressor gene Dicer was paradoxically overexpressed in ovarian tumor stroma, and induced fibroblast activation and stromal inflammation. Dicer transformed normal fibroblasts to a carcinoma-associated fibroblast (CAF)-like state, which was morphologically spread out and functionally activated to fuel tumor invasion and metastasis. Attenuation of Dicer hampered CAF characteristics, diminished stromal inflammation and the role of fibroblasts in supporting tumor growth. Moreover, Dicer drove the expression of an "inflammatory signature" in fibroblasts that could be used to discriminate normal and cancerous stroma and predict the survival of patients with OC. Finally, the nuclear factor κ B (NFκB) signaling was demonstrated to be responsible for Dicer effect on fibroblast activation and stromal inflammation, through microRNA (miR)-6780b. Our study represents the first report that characterizes Dicer expression and function in the tumor stroma, and highlights its pro-metastatic role in this context. Additionally, we suggest that the Dicer-miR6780b-NFκB cascade is an attractive target of choice in stroma-oriented OC therapy.

TGFβ1 in fibroblasts-derived exosomes promotes epithelial-mesenchymal transition of ovarian cancer cells

Cancer-associated fibroblasts (CAF), a major component of the tumor microenvironment, play an important role in interacting with neoplastic cells to promote ovarian cancer progression. Exosomes are nano-sized vesicles that mediate the cross-talk between different cell types. An increasing number of studies have focused on the fact that tumor cell-derived exosomes influence stromal cells. However, the mechanism by which CAF-derived exosomes modulate cancer cells in ovarian cancer remains obscure. To investigate the role of CAF exosomes in ovarian cancer, we examined the exosomal content of paired primary, metastatic and normal fibroblasts from seven stage IIIC ovarian cancer patients by ELISA. We found that in ovarian CAF-derived exosomes, TGFβ1 was upregulated compared to normal omentum fibroblasts (NOF). Exosomes derived from CAF were taken up by ovarian SKOV-3 and CAOV-3 cell lines during co-culture and induced malignant behaviors in cancer cells, including an enhanced migration and invasion ability and the promotion of epithelial-mesenchymal transition (EMT) by activating the SMAD signaling pathway. Our results indicate that the role of TGFβ1 in CAF exosomes triggers ovarian cancer cells into a more aggressive phenotype, suggesting that targeting CAF exosomes could be a potential treatment in ovarian cancer.

Naturally occurring mitochondrial-derived peptides are age-dependent regulators of apoptosis, insulin sensitivity, and inflammatory markers

Mitochondria are key players in aging and in the pathogenesis of age-related diseases. Recent mitochondrial transcriptome analyses revealed the existence of multiple small mRNAs transcribed from mitochondrial DNA (mtDNA). Humanin (HN), a peptide encoded in the mtDNA 16S ribosomal RNA region, is a neuroprotective factor. An in silico search revealed six additional peptides in the same region of mtDNA as humanin; we named these peptides small humanin-like peptides (SHLPs). We identified the functional roles for these peptides and the potential mechanisms of action. The SHLPs differed in their ability to regulate cell viability in vitro. We focused on SHLP2 and SHLP3 because they shared similar protective effects with HN. Specifically, they significantly reduced apoptosis and the generation of reactive oxygen species, and improved mitochondrial metabolism in vitro. SHLP2 and SHLP3 also enhanced 3T3-L1 pre-adipocyte differentiation. Systemic hyperinsulinemic-euglycemic clamp studies showed that intracerebrally infused SHLP2 increased glucose uptake and suppressed hepatic glucose production, suggesting that it functions as an insulin sensitizer both peripherally and centrally. Similar to HN, the levels of circulating SHLP2 were found to decrease with age. These results suggest that mitochondria play critical roles in metabolism and survival through the synthesis of mitochondrial peptides, and provide new insights into mitochondrial biology with relevance to aging and human biology.

Reprogramming of stromal fibroblasts by SNAI2 contributes to tumor desmoplasia and ovarian cancer progression

BACKGROUND

Molecular profiling in ovarian cancer (OC) revealed that the desmoplasia subtype presented the poorest prognosis, highlighting the contribution of stromal fibroblasts in tumor progression. This study aimed to investigate the molecular characteristics of SNAI2 driving the transcriptional reprogramming of fibroblasts within tumors.

METHODS

SNAI2 expression was evaluated in microdissected profiles of various cancers and in various molecular subtypes of OC. Gene set enrichment analysis (GSEA) and single sample GSEA (ssGSEA) were performed to explore the correlation between SNAI2 and stromal fibroblast activation. The SNAI2 defined signature in the mesenchymal OC subtype was identified through an integrative analysis of the TCGA and the Tothill datasets. The predictive value of this signature was validated in independent datasets. SNAI2 expression alteration influence of tumor growth in primary CAFs was evaluated in 3D organotypic and murine xenograft models.

RESULTS

We demonstrated that SNAI2 was frequently activated in the tumor stroma, correlated with fibroblast activation and worse patient outcome in OC. SNAI2 transformed normal fibroblasts to a CAF-like state and boosted their tumor-supporting role in 3D organotypic culture and in OC xenograft model. SNAI2 drove a transcriptional signature in the mesenchymal subtype of OC that contributed to tumor desmoplasia, which fed back to increase SNAI2 expression and sustain fibroblast activation.

CONCLUSIONS

Our results address the role of SNAI2 in reprogramming stromal fibroblasts. The identified SNAI2 mesenchymal signature has both a predictive value and biological relevance and might be a therapeutic target for stroma-oriented therapy against the desmoplasia OC subtype.

Targeting Leptin as a Therapeutic Strategy against Ovarian Cancer Peritoneal Metastasis

BACKGROUND/AIMS

Epithelial ovarian cancer (OC) is the leading cause of death in patients with gynecologic malignancy. Malignant ascites, a shared symptom of advanced OC patients, plays an important role in the peritoneal metastasis cascade of OC. Since leptin existed in great amount in malignant ascites, we speculated that it might be involved in the modulation of tumor cells malignant behavior.

METHOD

Here, we demonstrated that blocking of leptin could significantly suppress ovarian malignant ascitesinduced metastatic aggravation of OC cells. Furthermore, our results suggested that leptin was highly expressed in OC and correlated with poor outcome of OC patients. Recombinant leptin notably promoted the migration, invasion and proliferation of OC cells.

RESULT

Mechanistically, we found that leptin induced epithelial-mesenchymal transition (EMT) program in OC cells through the activation of the PI3K/Akt/mTOR pathway. Pharmacological inhibition of the PI3K/Akt/mTOR pathway partly impaired leptin-induced malignant transformation of OC cells. More importantly, our in vivo xenograft experiment showed that blocking of leptin could dramatically inhibit OC cells peritoneal dissemination.

CONCLUSION

Collectively, this study emphasized the importance of leptin in OC progression and illustrated a novel mechanism that the PI3K/Akt/mTOR pathway was involved in leptin-induced EMT. Our findings provide new insights into leptin exertion on OC metastasis and identify the potential of leptin neutralizing as a novel strategy against OC peritoneal dissemination.

The p38 MAPK inhibitor BIRB796 enhances the antitumor effects of VX680 in cervical cancer

VX680 is a potent and selective inhibitor that targets the Aurora kinase family. The p38 mitogen-activated protein kinase (MAPK) regulates a large number of cellular pathways and plays an important role in the regulation of cell survival and apoptosis. This study aimed to evaluate the effect of VX680 on cervical cancer cells and investigate whether the effects on apoptosis are enhanced by the ablation of p38 MAPK activation. The results suggested that VX680 inhibited the proliferation of cervical cancer cells by causing G2/M phase arrest and endoreduplication and that the apoptotic effect was attenuated by the activation of p38 MAPK. However, the addition of BIRB796, which is an important p38 MAPK inhibitor, effectively eliminated the expression of p-p38 and hence significantly enhanced the cell death induced by VX680 in vitro. Further study demonstrated that BIRB796 cooperated with VX680 to suppress cervical cancer cell growth in a mouse xenograft model. Taken together, our results demonstrated that VX680 induced cell cycle arrest and endoreduplication in human cervical cancer cells. Combined treatment with VX680 and BIRB796 synergistically inhibited tumor growth both in vitro and in vivo. Dual blockade of Aurora kinases and p38 MAPK is therefore a promising strategy for cervical cancer treatment.

Loss of the novel mitochondrial protein FAM210B promotes metastasis via PDK4-dependent metabolic reprogramming

Recent advances in tumor metabolism have revealed that metabolic reprogramming could dramatically promote caner metastasis. However, the relation and mechanism between metastasis and metabolic reprogramming are not thoroughly explored. Cell proliferation, colony formation, and invasion analysis were performed to evaluate the role of FAM210B in human cancer cells. Human ovarian cancer xenograft model was used to determine the effects of inhibiting FAM210B by shRNA on tumor metastasis. Microarray analysis was used to determine the target genes of FAM210B. FAM210B cellular localization was performed by mitochondria isolation and mitochondria protein extraction. To detect FAM210B-mediated metabolic reprogramming, oxygen consumption rate and extracellular acidification rate were measured. Our previous study screened a novel cancer progression-suppressor gene, FAM210B, which encodes an outer mitochondrial membrane protein, by the suppression of mortality by antisense rescue technique (SMART). Here we demonstrated that FAM210B loss was significantly associated with cancer metastasis and decreased survival in a clinical setting. Additionally, it was found that low expression of FAM210B was significantly correlated with decreased survival and enhanced metastasis in vivo and in vitro, and the loss of FAM210B led to an increased mitochondrial respiratory capacity and reduced glycolysis through the downregulation of pyruvate dehydrogenase kinase 4 (PDK4), which activated the EMT program and enhanced migratory and invasive properties. Collectively, our data unveil a potential metabolic target and mechanism of cancer metastasis.

Bio-informatics analysis of renal carcinoma gene matrix metalloproteinase-7

BACKGROUND

Renal cancer is one of the common malignant tumors of the urinary system, seriously threatening human being's health. The current discoveries, however, are far enough for efficient and secure treatment of renal cancer.

AIMS

The aim was to explore the mechanism of matrix metalloproteinase-7 (MMP-7) protein in renal carcinoma cell metastasis by bioinformatics analysis.

MATERIALS AND METHODS

Bioinformatics methods were used to analyze the composition of amino acids, as well as transmembrane structure, coiled coils, subcellular localization, signal peptide, functions and structures at all levels.

RESULTS AND CONCLUSIONS

It showed that the gene MMP-7 totally had 1131 bp. A peptide chain containing 267 amino acids was encoded in the coding region. Based on random coil, α helix, and further super-helix, it had formed a stable neutral hydrophilic protein. The subcellular location analysis indicated that the protein was located outside the cell. The mature peptide started from the 18th amino acid, and its front-end was the sequence of the signal peptide, belonging to the secreted protein. Analysis of the functional domain showed that this protein had two functional domains, the PG binding domain, and the zinc finger binding domain. Moreover, the protein, which was cross-linked with it, was also one related to cancer cell proliferation and metastasis. To sum up, MMP-7 is a stable neutral hydrophilic secreted protein, and it may play a vital role in the invasion and metastasis of cancer cells.

Smad4 deletion in blood vessel endothelial cells promotes ovarian cancer metastasis

SMAD4 is a critical co-smad in signal transduction pathways activated in response to transforming growth factor-β (TGF-β)-related ligands, regulating cell growth and differentiation. The roles played by SMAD4 inactivation in tumors highlighted it as a tumor-suppressor gene. Herein, we report that loss of SMAD4 expression in vascular endothelial cells promotes ovarian cancer invasion. SiRNA transfer of this gene in the HUVEC reduced SMAD4 protein expression and function. Although it reduced the vessel endothelial cell tubule formation in vitro and in vivo, it did not affect the tumor growth significantly in vivo. However, it weakened the barrier integrity in endothelial cells and increased vessel permeability and the ovarian cancer liver metastasis. We documented reduced angiogenesis and increased invasion histologically and by intravital microscopy, and gained mechanistic insight at the messenger and gene level. Finally, we found a negative reciprocal regulation between SMAD4 and FYN. FYN is one of the Src family kinases (SFK), activation of which can cause dissociation of cell-cell junctions and adhesion, resulting in paracellular hypermeability. Upon SMAD4 deletion, we detected high expression levels of FYN in vessel endothelial cells, suggesting the mechanism of the ovarian tumor cells cross the endothelial barrier and transform to an invasive phenotype.

Genome-wide association study identifies four SNPs associated with response to platinum-based neoadjuvant chemotherapy for cervical cancer

To identify genomic markers associated with the response to neoadjuvant chemotherapy (NACT) in patients with cervical cancer, we performed a three-stage genome-wide association study (GWAS) in the Han Chinese population. A total of 596 patients with stage IA2-IIIB cervical cancer were enrolled in this study. One single nucleotide polymorphism (SNP) (rs6812281, per allele OR = 2.37, P = 9.0 × 10⁻⁹) located at 4q34.3 reached GWAS significance (P < 5.0 × 10⁻⁸). Another three SNPs, rs4590782 (10q26.2, P = 1.59 × 10⁻⁵, per allele OR = 0.48), rs1742101 (14q32.11, P = 7.11 × 10⁻⁶, per allele OR = 0.52), and rs1364121 (16q23.3, P = 3.15 × 10⁻⁶, per allele OR = 1.98), exhibited strong evidence of associations with response to neoadjuvant chemotherapy. Patients with a C allele (CT + CC) of rs4590782 had better 5-year overall survival rates (82.9% vs. 75.8%, P = 0.083) and 5-year disease-free survival rate (80.8% vs. 72.7%, P = 0.021) than those without a C allele. Our findings help to characterize the genetic etiology of the response to neoadjuvant chemotherapy in patients with cervical cancer.

Prognostic and therapeutic value of disruptor of telomeric silencing-1-like (DOT1L) expression in patients with ovarian cancer

Background

Epigenetics has been known to play a critical role in regulating the malignant phenotype. This study was designed to examine the expression of DOT1L (histone 3 lysine 79 methyltransferase) and H3K79 methylation in normal ovarian tissues and ovarian tumors and to explore the function of DOT1L and its underline mechanisms in ovarian cancer.

Methods

The expression of DOT1L and H3K79 methylation in 250 ovarian tumor samples and 24 normal ovarian samples was assessed by immunohistochemistry. The effects of DOT1L on cell proliferation in vitro were evaluated using CCK8, colony formation and flow cytometry. The DOT1L-targeted genes were determined using chromatin immune-precipitation coupled with high-throughput sequencing (ChIP-seq) and ChIP-PCR. Gene expression levels were measured by real-time PCR and immunoblotting. The effects of DOT1L on tumor growth in vivo were evaluated using an orthotopic ovarian tumor model.

Results

DOT1L expression and H3K79 methylation was significantly increased in malignant ovarian tumors. High DOT1L expression was associated with International Federation of Gynecology and Obstetrics (FIGO) stage, histologic grade, and lymphatic metastasis. DOT1L was an independent prognostic factor for the overall survival (OS) and progression-free survival (PFS) of ovarian cancer, and higher DOT1L expression was associated with poorer OS and PFS. Furthermore, DOT1L regulates the transcription of G1 phase genes CDK6 and CCND3 through H3K79 dimethylation; therefore, blocking DOT1L could result in G1 arrest and thereby impede the cell proliferation in vitro and tumor growth in vivo.

Conclusions

Our findings first demonstrate that DOT1L over-expression has important clinical significance in ovarian cancer and also clarify that it drives cell cycle progression through transcriptional regulation of CDK6 and CCND3 through H3K79 methylation, suggesting that DOT1L might be potential target for prognostic assessment and therapeutic intervention in ovarian cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-017-0400-8) contains supplementary material, which is available to authorized users.

Geldanamycin, an inhibitor of Hsp90, increases paclitaxel-mediated toxicity in ovarian cancer cells through sustained activation of the p38/H2AX axis

Paclitaxel is a mitotic inhibitor used in ovarian cancer chemotherapy. Unfortunately, due to the rapid genetic and epigenetic changes in adaptation to stress induced by anticancer drugs, cancer cells are often able to become resistant to single or multiple anticancer agents. However, it remains largely unknown how paclitaxel resistance happens. In this study, we generated a cell line of acquired resistance to paclitaxel therapy, A2780T, which is cross-resistant to other antimitotic drugs, such as PLK1 inhibitor or AURKA inhibitor. Immunoblotting revealed significant alterations in cell-cycle-related and apoptotic-related proteins involved in key signaling pathways. In particular, phosphorylation of p38, which activates H2AX, was significantly decreased in A2780T cells compared to the parental A2780 cells. Geldanamycin (GA), an inhibitor of Hsp90, sustained activation of the p38/H2AX axis, and A2780T cells were shown to be more sensitive to GA compared to A2780 cells. Furthermore, treatment of A2780 and A2780T cells with GA significantly enhanced sensitivity to paclitaxel. Meanwhile, GA cooperated with paclitaxel to suppress tumor growth in a mouse ovarian cancer xenograft model. In conclusion, GA may sensitize a subset of ovarian cancer to paclitaxel, particularly those tumors in which resistance is driven by inactivation of p38/H2AX axis.

Elaiophylin, a novel autophagy inhibitor, exerts antitumor activity as a single agent in ovarian cancer cells

Currently, targeting the autophagic pathway is regarded as a promising new strategy for cancer drug discovery. Here, we screened the North China Pharmaceutical Group Corporation's pure compound library of microbial origin using GFP-LC3B-SKOV3 cells and identified elaiophylin as a novel autophagy inhibitor. Elaiophylin promotes autophagosome accumulation but blocks autophagic flux by attenuating lysosomal cathepsin activity, resulting in the accumulation of SQSTM1/p62 in various cell lines. Moreover, elaiophylin destabilizes lysosomes as indicated by LysoTracker Red staining and CTSB/cathepsin B and CTSD/ cathepsin D release from lysosomes into the cytoplasm. Elaiophylin eventually decreases cell viability, especially in combination with cisplatin or under hypoxic conditions. Furthermore, administration of a lower dose (2 mg/kg) of elaiophylin as a single agent achieves a significant antitumor effect without toxicity in an orthotopic ovarian cancer model with metastasis; however, high doses (8 mg/kg) of elaiophylin lead to dysfunction of Paneth cells, which resembles the intestinal phenotype of ATG16L1-deficient mice. Together, these results provide a safe therapeutic window for potential clinical applications of this compound. Our results demonstrate, for the first time, that elaiophylin is a novel autophagy inhibitor, with significant antitumor efficacy as a single agent or in combination in human ovarian cancer cells, establishing the potential treatment of ovarian cancer by this compound.

[Preliminary study for the roles and mechanisms of 20(R)-ginsenoside Rg3 and PEG-PLGA-Rg3 nanoparticles in the Lewis lung cancer mice]

OBJECTIVE

To comparatively observe the effects of 20(R)-ginsenoside Rg3 and PEG-PLGA-Rg3 nanoparticles on the Lewis lung cancer mice and to explore the mechanisms of Rg3 and PEG-PLGA-Rg3 nanoparticle anti-cancer in vivo.

METHODS

Lewis lung cancer mouse model was established and 60 mice were randomly divided into 5 groups with twelve in each group: PEG-PLGA-Rg3 nanoparticles group(Rg3-N), PEG-PLGA group (PEG), Rg3 group (Rg3), normal control group(C), saline control group(NS), and received intragastric administration for 14 days. The weights of the mice were measured every 2 days and the weight curves were obtained. At the same time, the color pattern, activity and mental status were observed. The mice were sacrificed when the administration was over, and the effects of 20(R)-ginsenoside Rg3 and PEG-PLGA-Rg3 nanoparticles on tumor weight, and the tumor:weight ratios were analysed. In addition, the tumor microvessel density (MVD) was measured by immunohistochemical staining with anti-CD31 antibody to compare the effects of Rg3 and PEG-PLGA-Rg3 nanoparticles on the tumor angiogenesis in vivo. Furthermore, the levels of such angiogenesis and proliferation factors as MMP-9, HIF-1α, VEGF, Ki-67 were examined by RT-PCR, Western blot and immunohistochemistry to explore the internal molecular mechanisms of anti-tumor effects in vivo.

RESULTS

The trends of variation of the mice weights in NS group and PEG group were rising early but declining later. In contrast, the trends of the other three groups were rising early and became stable later. In comparison with NS group, the mice of Rg3 group and Rg3-N group had better general status: brighter color, more active and better spirit. Compared with NS group,the tumor weight in PEG group, Rg3 group and Rg3-N group showed no significant difference but the tumor:weight ratio and MVD in Rg3 group and Rg3-N group declined significantly (P<0.01). Besides, there was no significant difference between Rg3 group and Rg3-N group. At the same time, the level of VEGF mRNA, the protein expression of MMP-9, HIF-1α, VEGF in Rg3 group and Rg3-N group decreased compared with NS group. Furthermore, the level of each index above-mentioned in Rg3-N group was lower than that in Rg3 group. The expression of Ki-67 in PEG group, Rg3 group and Rg3-N group showed no significant difference compared with NS group.

CONCLUSION

Rg3 and PEG-PLGA-Rg3 nanoparticle may suppress the expression of VEGF, MMP-9 and HIF-1α in Lewis lung cancer mice, thereby indirectly contributing to their antitumor effects and alleviating the mice's general status. In addition, PEG-PLGA nanoparticles embedding can promote Rg3 antitumor effect in vivo.

Co-targeting EGFR and Autophagy Impairs Ovarian Cancer Cell Survival during Detachment from the ECM

Ovarian cancer (OC) remains the most aggressive and lethal gynecological tumor characterized by massive intraperitoneal dissemination and malignant ascites. The carcinoma cells exfoliated from the primary tumor and were further transformed in the ascites microenvironment. During this suspension process, multi-cellular spheroids are formed and these aggregates represent an invasive and chemoresistant cellular population fundamental to metastatic dissemination. Activation of EGFR signaling is involved in increased cell metastasis and decreased apoptosis of ovarian cancer. The application of EGFR Inhibition in ovarian cancer was hampered for its limited benefit as a solitary therapy. In this work, our results primarily indicated that autophagy was induced in response to EGFR specific inhibitor AG1478 in OC cell lines generated spheres and ascites primary spheroids, characterized by the elevation of LC3-II, Beclin1 and Atg5. Blockage of autophagy with 3MA notably promoted spheroid death in suspension as well as AG1478-induced cell apoptosis, suggesting a protective autophagy contribution during tumor cells in suspension or under EGFR inhibition. Consequently, inhibiting autophagy with 3MA significantly enhanced the inhibitory effect of AG1478 on tumor cell peritoneal propagation in SKOV3 i.p. xenografts model. In addition, elevated EGFR, Beclin1, and Atg5 mRNA levels were associated with decreased ovarian cancer patient survival. Together, our findings suggested that targeting autophagy held the potential to improve EGFR inhibition benefit in the treatment of ovarian cancer cells during detachment from the extra-cellular matrix (ECM), and that this combination strategy might provide a new treatment option in controlling peritoneal metastasis of ovarian cancer.

The role of Sema4D/CD100 as a therapeutic target for tumor microenvironments and for autoimmune, neuroimmune and bone diseases

INTRODUCTION

Semaphorin 4D (Sema4D), also known as CD100, has been implicated in physiologic roles in the immune and nervous systems. However, the interaction of Sema4D with its high affinity receptor, Plexin-B1, reveals a novel role for Sema4D produced by the tumor microenvironment in tumor angiogenesis and metastasis.

AREAS COVERED

The ligation of Sema4D/CD100 with CD72 on immune and inflammatory cells is known to stimulate immune responses and regulation. Because CD100 and CD72 are expressed on lung immune and nonimmune cells, as well as on mast cells, the CD100/CD72 interaction plays another important role in allergic airway inflammation and mast cell functions. A better understanding of Sema4D-mediated cell signaling in physiological and pathological processes may be crucial for crafting new Sema4D-based therapeutics for human disease and tumor microenvironments. Strategies to achieve effective management through treatment with Sema4D include special siRNAs, neutralizing antibodies and knockdown.

EXPERT OPINION

This review focuses on the links between Sema4D and human diseases such as cancer, bone metabolism, immune responses and organ development. The current knowledge regarding the expression of Sema4D and its receptors and its functional roles is systemically reviewed to explore Sema4D as both a target and a therapeutic in human diseases.

Quercetin induces endoplasmic reticulum stress to enhance cDDP cytotoxicity in ovarian cancer: involvement of STAT3 signaling

There is an urgent need to make cisplatin (cDDP) more effective and less toxic in the treatment of ovarian cancer for its systemic side effects and high resistance rate. In this study, we investigated the effect of quercetin (Qu) pretreatment on the potentiation of cDDP in ovarian cancer. We found that Qu pretreatment significantly enhanced cDDP cytotoxicity in an ovarian cancer cell line and primary cancer cells. In addition, we demonstrated that Qu elicited obvious endoplasmic reticulum stress (ERS) and activated all three branches of ERS in ovarian cancer. Specific inhibitors of each ERS pathway, as well as the general ERS stabilizer tauroursodeoxycholic acid, notably diminished such enhancing effects. Furthermore, Qu notably suppressed STAT3 phosphorylation, leading to downregulation of the BCL-2 gene downstream of STAT3. Moreover, blocking ERS restored the protein levels of phosphorylated STAT3 as well as BCL-2 expression, thus abolishing the chemosensitization potency of Qu; these results revealed that Qu affected the STAT3 pathway to enhance cDDP cytotoxicity, and this effect involved ERS signaling. In a xenograft mouse model of ovarian cancer, Qu enhanced the antitumor effect of cDDP. Tumors from mice treated with cDDP in combination with Qu pretreatment had repressed STAT3 phosphorylation, lower BCL-2 and higher apoptosis levels compared with those from the other groups. Meanwhile, Qu markedly reduced the elevation of blood creatinine during cDDP intervention. These data indicate that Qu pretreatment potentiates the antitumor effects of cDDP in ovarian cancer while protecting the kidneys against damage. Therefore the strategy of Qu pretreatment may be beneficial in enhancing the therapeutic efficacy of cDDP against ovarian cancer.

TALEN-mediated targeting of HPV oncogenes ameliorates HPV-related cervical malignancy

Persistent HPV infection is recognized as the main etiologic factor for cervical cancer. HPV expresses the oncoproteins E6 and E7, both of which play key roles in maintaining viral infection and promoting carcinogenesis. While siRNA-mediated targeting of E6 and E7 transcripts temporarily induces apoptosis in HPV-positive cells, it does not eliminate viral DNA within the host genome, which can harbor escape mutants. Here, we demonstrated that specifically targeting E6 and E7 within host DNA with transcription activator-like effector nucleases (TALENs) induces apoptosis, inhibits growth, and reduces tumorigenicity in HPV-positive cell lines. TALEN treatment efficiently disrupted E6 and E7 oncogenes, leading to the restoration of host tumor suppressors p53 and retinoblastoma 1 (RB1), which are targeted by E6 and E7, respectively. In the K14-HPV16 transgenic mouse model of HPV-driven neoplasms, direct cervical application of HPV16-E7-targeted TALENs effectively mutated the E7 oncogene, reduced viral DNA load, and restored RB1 function and downstream targets transcription factor E2F1 and cycling-dependent kinase 2 (CDK2), thereby reversing the malignant phenotype. Together, the results from our study suggest that TALENs have potential as a therapeutic strategy for HPV infection and related cervical malignancy.

Evaluation of (99m)Tc-HYNIC-TMTP1 as a tumor-homing imaging agent targeting metastasis with SPECT

INTRODUCTION

TMTP1 (NVVRQ) is a novel tumor-homing peptide, which specifically targets tumor metastases, even at the early stage of occult metastasis foci. Fusing TMTP1 to therapeutic peptides or proteins can increase its anti-cancer efficacy both in vivo and in vitro. Here, we labeled TMTP1 with (99m)Tc to evaluate its targeting properties in an ovarian cancer xenograft tumor mouse model and a gastric cancer xenograft mouse model.

METHODS

The invasion ability of SKOV3 and highly metastatic SKOV3.ip cell lines were performed by the Transwell Invasion Assays, and then Rhodamine-TMTP1 was used to detect its affinity to these two cells. Using the co-ligand ethylenediamine-N, N'-diacetic acid (EDDA) and the bifunctional chelator 6-hydrazinonicotinic acid (HYNIC), the TMTP1 peptide was labeled with (99m)Tc. A cell-binding assay was performed by incubating cancer cells with (99m)Tc-HYNIC-TMTP1 with or without an excess dose of cold HYNIC-TMTP1. To evaluate the probe in vivo, nude mice bearing SKOV3, SKOV3.ip and MNK-45 tumor cells were established and subjected to SPECT imaging after injection with (99m)Tc-HYNIC-TMTP1. Ex vivo γ-counting of dissected tissues from the mice was used to evaluate its biodistribution.

RESULTS

(99m)Tc-HYNIC-TMTP1 was successfully synthesized. The radiotracer also exhibited high hydrophilicity and excellent stability in vitro and in vivo. It has strong affinity to highly metastatic cancer cell lines but not to poorly metastatic cell lines. After mice were injected with (99m)Tc-HYNIC-TMTP1, non-invasive SPECT imaging detected SKOV3.ip and MNK-45 xenograft tumors but not SKOV3 xenograft tumors. This result can be inhibited by excess HYNIC-TMTP1. The uptake of (99m)Tc-HYNIC-TMTP1 in SKOV3.ip xenograft tumors was 0.182±0.017% ID/g at 2h p.i. with high renal uptake (74.32±15.05% ID/g at 2h p.i.).

CONCLUSION

(99m)Tc-HYNIC-TMTP1 biodistribution and SPECT imaging demonstrated its ability to target highly metastatic tumors. Therefore, metastasis can be non-invasively investigated by SPECT imaging using (99m)Tc-HYNIC-TMTP1. Meanwhile, this radiotracer has some shortages in the low % ID/g of tumors and high accumulation in the kidney.