Metastasis In Nude Mice Research Articles

Erratum.

Overexpression of the tumor necrosis factor receptor-associated factor 4 (TRAF4) has been detected in many cancer types and is considered to foster tumor progression. However, the role of TRAF4 in hepatocellular carcinoma (HCC) remains elusive. In this study, we found that TRAF4 was highly expressed in HCC cell lines and HCC tissues compared with normal liver cell lines and adjacent noncancerous tissues. TRAF4 overexpression in HCC tissues was correlated with tumor quantity and vascular invasion. In vitro studies showed that TRAF4 was associated with HCC cell migration and invasion. An in vivo study verified that TRAF4 overexpression facilitated metastasis in nude mice. In addition, overexpressed TRAF4 promoted the phosphorylation of Akt and induced Slug overexpression, leading to downregulated E-cadherin and upregulated vimentin, while silencing TRAF4 moderated the phosphorylation of Akt and repressed the expression of Slug, which resulted in upregulated E-cadherin and downregulated vimentin. These effects were inversed after pretreatment of the PI3K/Akt inhibitor LY294002 or overexpression of constitutively active Akt1. Our study demonstrated that TRAF4 was involved in promoting HCC cell migration and invasion. The process was induced by the EMT through activation of the PI3K/Akt signaling pathway.

Long Non-Coding RNA AC118344.1 Promotes Gastric Cancer Cell Proliferation, Invasion, and Metastasis via AKT2 and Its Downstream Molecules HK2 and MMP2.

BackgroundGastric cancer (GC) is a highly occurring cancer with poor prognosis. Reports indicate that long non-coding RNA (LncRNA) potentially regulates tumor progression. Herein, we aim to explore the effect of LncRNA AC118344.1 on the progression of gastric cancer.MethodsOverexpression and knockout experiments were used to clarify the potential molecular signaling mechanisms induced by AC118344.1. CCK-8, transwell and in vivo metastasis assay were used to detect the function of AC118344.1 in AGS and SGC-7901 cells. Additionally, shRNA silencing techniques, qRT-PCR and Western blot assay were used to explore the relationship between AC118344.1, AKT2, and its downstream molecules.ResultsUpregulating the expression of AC118344.1 induces cell proliferation, invasion in vitro, and lung metastasis in vivo whereas downregulating the expression of AC118344.1 inhibits these effects. Besides, silencing the expression of AC118344.1 downregulated the expression of AKT2 in both the two cells. On the other hand, silencing the expression of AKT2 by shRNA was unable to downregulate the expression of AC118344.1 in both the gastric cancer cells. Also, AC118344.1 regulated AKT2 via its downstream molecules including HK2 and MMP2.ConclusionAC118344.1 promotes gastric cancer cell proliferation and invasion and lung metastasis in nude mice by upregulating the expression of AKT2 and its downstream molecules (HK2 and MMP2). Therefore, our findings provide a novel mechanism of the AC118344.1-AKT2-HK2/MMP2 axis in regulating the development of gastric cancer cells.

HN1L promotes migration and invasion of breast cancer by up-regulating the expression of HMGB1.

Recent reports showed that haematological and neurological expressed 1‐like (HN1L) gene participated in tumorigenesis and tumour invasion. However, the expression and role of HN1L in breast cancer remain to be investigated. Here, bioinformatics, western blot and immunohistochemistry were used to detect the expression of HN1L in breast cancer. Wound healing, transwell assay, immunofluorescence assay and mass spectrum were used to explore the role and mechanism of HN1L on the migration and invasion of breast cancer, which was confirmed in vivo using a nude mice model. Results showed that HN1L was significantly over‐expressed in breast cancer tissues, which was positively correlated with M metastasis of breast cancer patients. Silencing HN1L significantly inhibited the invasion and metastasis of breast cancer cells in vitro and lung metastasis in nude mice metastasis model of breast cancer. Mechanistically, HN1L interacted with HSPA9 and affected the expression of HMGB1, playing a key role in promoting the invasion and metastasis of breast cancer cell. These results suggested that HN1L was an appealing drug target for breast cancer.

VWCE Functions as a Tumor Suppressor in Breast Cancer Cells.

Breast cancer remains a leading cause of cancer-related death, for which the majority of deaths result from metastases. Von Willebrand factor C and EGF domain (VWCE) is a member of the Von Willebrand factor (VWF) gene family; however, its function, regulatory mechanism, and clinical value in breast cancer remain unclear. In the present study, we sought to elucidate the role of VWCE in breast cancer metastasis. We examined the expression of VWCE in breast cancer tissues and normal control tissues of 50 breast cancer patients. We found that VWCE expression was downregulated in breast cancer cells and tissues compared to normal breast epithelial cells or the adjacent normal tissues. To explore the role of VWCE in human breast cancer development, we introduced a VWCE-overexpressing or control lentiviral vector into the breast cancer MDA-MB-453 and MDA-MB-231 lines in vitro. The overexpression of VWCE inhibited the proliferation, migration, invasion, and chemoresistance of the breast cancer cell lines. More importantly, the forced expression of VWCE suppressed tumor formation and metastasis in nude mice. iTRAQ-based quantitative proteomic analysis revealed that VWCE overexpression induced a 10-fold decrease in the level of WD-repeat domain 1 (WDR1) protein expression. Rescue experiments further verified that WDR1 was a downstream molecule of VWCE, and WDR1 overexpression reversed the above effects of VWCE overexpression on tumor growth. Therefore, VWCE may represent a novel tumor suppressor, for which its deregulation promotes breast cancer progression via the upregulation of WDR1.

Quercetin suppresses pancreatic ductal adenocarcinoma progression via inhibition of SHH and TGF-β/Smad signaling pathways.

Pancreatic ductal adenocarcinoma (PDA) is an aggressive type of malignant tumor with a poor prognosis and high mortality. Aberrant activation of hedgehog signaling plays a crucial role in the maintenance and progression of PDA. Here, we report that the dietary bioflavonoid quercetin has therapeutic potential for PDA by targeting sonic hedgehog (SHH) signaling. The effects of quercetin on the proliferation, apoptosis, migration, and invasion of pancreatic cancer cells (PCCs) and tumor growth and metastasis in PDA xenograft mouse models were evaluated. Additionally, SHH signaling activity was determined. Quercetin significantly inhibited PCC proliferation by downregulating c-Myc expression. In addition, quercetin suppressed epithelial-mesenchymal transition (EMT) by reducing TGF-β1 level, which resulted in inhibition of PCC migration and invasion. Moreover, quercetin induced PCC apoptosis through mitochondrial and death receptor pathways. In nude mouse models, PDA growth and metastasis were reduced by quercetin treatment. Mechanically, quercetin exerts its therapeutic effects on PDA by decreasing SHH activity. Interestingly, quercetin-induced SHH inactivation is mainly dependent on Gli2, but not Gli1. Enhance SHH activity by recombinant Shh protein abolished the quercetin-mediated inhibition of PCC proliferation, migration, and invasion. Furthermore, Shh activated TGF-β1/Smad2/3 signaling and promoted EMT by inducing the expression of Zeb2 and Snail1 that eventually resulted in a partial reversal of quercetin-mediated inhibition of PCC migration and invasion. We conclude that quercetin inhibited the growth, migration, and invasion and induced apoptosis of PCCs by antagonizing SHH and TGF-β/Smad signaling pathways. Thus, quercetin may be a potential candidate for PDA treatment.

Chinese herbal formula QHF inhibits hepatocellular carcinoma metastasis via HGF/c-Met signaling pathway

Hepatocellular Carcinoma (HCC) is one of the most common malignant tumors, and high recurrence and metastasis are the major obstacles to successful treatment of HCC. Traditional Chinese medicine has little known and unique advantages in the treatment of HCC. Previous studies have confirmed that Chinese herbal formula Qingrejiedu (clears away heat and toxins), Huoxuehuayu (promotes blood flow to remove stasis) and Fuzhengguben (strengthens healthy qi and root) (QHF) has a significant effect on patients with advanced HCC, improves the quality of life and prolongs the survival time of patients significantly. In this study, we investigated the effect of QHF on proliferation, migration and invasion of human high metastatic hepatocellular carcinoma cell line HCCLM3 and its underlying mechanism. The results from our in vitro experiments showed that QHF has the ability to inhibit the proliferation by inducing G2/M phase cell cycle arrest and induce apoptosis. Moreover, QHF can also inhibit migration and invasion of HCCLM3 cells and the expression of the p-c-Met protein in HCCLM3 cells was down-regulated. c-Met is closely related to the metastasis of HCC, then we constructed a stable transfected cell line HepG2-met with high expression of c-Met by transfection. Further study in vivo revealed that c-Met gene will promote the growth of tumors and lung metastases in nude mice, and QHF intervention can reduce tumor lung metastases by inhibiting the HGF/c-Met signaling pathway. In conclusion, our study reveals that QHF can inhibit the proliferation, migration and invasion of HCCLM3, and this effect may be related to inhibiting HGF/c-Met signaling pathway.

Inhibition of microRNA-15b-5p Attenuates the Progression of Oral Squamous Cell Carcinoma via Modulating the PTPN4/STAT3 Axis.

BackgroundEmerging evidence has demonstrated the important functions of microRNAs (miRNAs) in human malignancies. This study focuses on the function of miR-15b-5p on the oral squamous cell carcinoma (OSCC) progression and the molecules involved.MethodsTumor and the paracancerous tissues were obtained from OSCC patients. Differentially expressed miRNAs between the tumor and normal tissues were screened out. miR-15b-5p expression in tumors and acquired cells was determined, and its correlation with patient survival was analyzed. Knockdown of miR-15b-5p was introduced in SCC-4 and CAL-27 cells to explore its role in cell growth and metastasis. Binding relationship between miR-15b-5p and PTPN4 was validated, and altered expression of PTPN4 was introduced in cells to explore its function in OSCC development. Xenograft tumors were induced in nude mice for in vivo experiments.ResultsmiR-15b-5p was abundantly expressed in OSCC tumors and cells and linked to poor survival in patients. Silencing of miR-15b-5p suppressed proliferation, migration, and invasion and triggered apoptosis in SCC-4 and CAL-27 cells. miR-15b-5p targeted PTPN4. Further silencing of PTPN4 blocked the inhibiting functions of miR-15b-5p inhibitor in OSCC cell growth. The in vitro results were reproduced in vivo, where inhibition of miR-15b-5p led to a decline in tumor growth and metastasis in nude mice. PTPN4 was found as a negative mediator of the STAT3 pathway.ConclusionThis study evidenced that miR-15b-5p possibly promotes OSCC development through binding to PTPN4 and the following STAT3 signaling activation. miR-15b-5p may be a potential therapeutic target for OSCC.

Abstract 5033: Targeted delivery of miR-122 into hepatocytes regresses liver metastasis

Abstract Background: Metastatic tumors in the liver are 20 times more common than primary tumors and considered as a leading cause of mortality in several types of cancer. Therefore, making the liver (soil) inhospitable for tumor cells (seeds) to grow will have tremendous effects on outcome of multiple types of cancer. RNAi delivery -including miRNA delivery-shows promise for the development of novel molecular therapeutics that interfere with genes causing metastasis. Mir-122, which accounts for 70% of total miRNA population within the liver, is also known as a tumor suppressor miRNA within liver. We hypothesized that miR-122 delivery into hepatocytes can prevent development of metastatic colorectal cancer within mice liver. For testing this hypothesis, we used hepatic injection of ex-vivo engineered liver metastasis from human colorectal cancer cells to induce hepatic metastasis in nude mice and employed lipid calcium phosphate (LCP) nanoparticles for delivery of miR-122. Methods: LCP-miR122 and LCP-miRNC (negative control miRNA) were prepared mixing an emulsion of calcium which contained miRNA with a phosphate emulsion, followed by addition of DOPA to make the inner core of LCP. The outer leaflet of LCP contained DOTAP, Cholesterol and DSPE-PEG as. Galactose was conjugated at LCP surface for its targeted delivery to hepatocytes. For induction of hepatic metastasis, HT29-Luc cells were grown on liver biomatrix (BMX) for 7-10 days to acquire metastatic features and then harvested and injected into portal veins of nu/nu mice. Hepatic metastases formation was monitored weekly in vivo using bioluminescent imaging. LCP-miR122 or LCP-miRNC was systematically injected three times a week for 3 weeks starting 24 hours after tumor inoculations. Results: LCP particles were found to be 25-50 nm via dynamic light scattering analysis. When injected in vivo, LCP containing miR-122 was majorly distributed into liver (80%) and was detected in hepatocytes through confocal microscopy and target gene expression analysis. LCP-miR122 did not show any sign of hepatotoxicity or renal toxicity or any other pathological damage to other major organs. The injected conditioned HT29 cells formed metastatic foci within liver 1-3 weeks after portal vein injection as detected by bioluminescent imaging. Interestingly, we found that 67% of (6 out of 9) mice treated with LCP-miR122 did not show any sign of liver metastasis after 3 weeks compared with only 20% (2 out of 10) of mice treated with LCP containing negative control miRNA [OR=0.12, 95% CI:0.015-0.99; p=0.05]. Monitoring liver metastasis expansion on weekly basis, mice treated with LCP-miR122 showed a slight decrease in number of liver metastatic foci compared with control mice which showed a significant increase in number of liver metastatic foci during treatment [0.7 vs 3.8-fold; p=0.05]. Conclusion: These results suggest that targeted delivery of miR-122 into hepatocytes of patients prone to liver metastasis or harboring liver metastasis can prevent or regress hepatic metastasis. Citation Format: Hossein Sendi, Nikhila Sultanpuram, Jie Wang, Amanda Graboski, Liantao Li, Mengying Hu, Leaf Huang, Andrew Z. Wang. Targeted delivery of miR-122 into hepatocytes regresses liver metastasis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5033.

DNMT1 and DNMT3B regulate tumorigenicity of human prostate cancer cells by controlling RAD9 expression through targeted methylation.

Prostate cancer is the second most common type of cancer and the second leading cause of cancer death in American men. RAD9 stabilizes the genome, but prostate cancer cells and tumors often have high quantities of the protein. Reduction of RAD9 level within prostate cancer cells decreases tumorigenicity of nude mouse xenographs and metastasis phenotypes in culture, indicating that RAD9 overproduction is essential for the disease. In prostate cancer DU145 cells, CpG hypermethylation in a transcription suppressor site of RAD9 intron 2 causes high-level gene expression. Herein, we demonstrate that DNA methyltransferases DNMT1 and DNMT3B are highly abundant in prostate cancer cells DU145, CWR22, LNCaP and PC-3; yet, these DNMTs bind primarily to the transcription suppressor in DU145, the only cells where methylation is critical for RAD9 regulation. For DU145 cells, DNMT1 or DNMT3B shRNA reduced RAD9 level and tumorigenicity, and RAD9 ectopic expression restored this latter activity in the DNMT knockdown cells. High levels of RAD9, DNMT1, DNMT3B and RAD9 transcription suppressor hypermethylation were significantly correlated in prostate tumors, and not in normal prostate tissues. Based on these results, we propose a novel model where RAD9 is regulated epigenetically by DNMT1 and DNMT3B, via targeted hypermethylation, and that consequent RAD9 overproduction promotes prostate tumorigenesis.

Long non coding RNA OIP5‑AS1 promotes metastasis of breast cancer via miR‑340‑5p/ZEB2 axis.

Breast cancer is the most common invasive cancer in women with the highest number of related deaths which is caused by distal metastasis. Recently, integrated analysis of gene expression profile suggested widespread gene dysregulation in various types of cancer. Research in the past decade has focused on long non-coding RNAs (lncRNAs), particularly in cell proliferation, tumor progression and metastasis. OPA-interacting protein 5 antisense transcript 1 (OIP5-AS1) is an evolutionarily conserved long non-coding RNA that has been linked to oncogenesis in multiple cancers. In breast cancer, dysregulation of OIP5-AS1 was reported but the precise role in cancer development and progression remains unclear. In the present study, using small interfering RNA (siRNA) targeting OIP5-AS1, it was shown that knockdown of OIP5-AS1 was associated with alteration of EMT markers and suppressed migration and invasion of breast cancer cells. Among the EMT-related transcription factors, ZEB1 and ZEB2 were significantly downregulated with OIP5-AS1 knockdown. Computational analysis and a dual-luciferase reporter system identified miR-340-5p was the target gene for OIP5-AS1. Further experiments verified the function of OIP5-AS1 in cell invasion was dependent on miR-340a-5p through regulating target gene ZEB2. In vivo study demonstrated that overexpressing OIP5-AS1 in breast cancer cells promoted lung metastasis in nude mice. The findings of the present study revealed the mechanism of OIP5-AS1 in breast cancer metastasis. Overall, our study may provide a potential therapeutic target for breast cancer metastasis.

The inhibition of microRNA-326 by SP1/HDAC1 contributes to proliferation and metastasis of osteosarcoma through promoting SMO expression.

Osteosarcoma (OS) is a malignant bone cancer lacking of effective treatment target when the metastasis occurred. This study investigated the implication of MicroRNA‐326 in OS proliferation and metastasis to provide the clue for the treatment of metastatic OS. This study knocked down SP1 in MG63 and 143B cells and then performed Microarray assay to find the expression of miRNAs that were influenced by SP1. MTT, EdU, wound‐healing and cell invasion assays were performed to evaluated cell proliferation and invasion. OS metastasis to lung was detected in a nude mice model. ChIP assay and DAPA were applied to determine the regulatory effect of SP1 and histone deacetylase 1 (HDAC) complex on miR‐326 expression. Human OS tissues showed lowly expressed miR‐326 but highly expressed Sp1 and HDAC. Sp1 recruited HDAC1 to miR‐326 gene promoter, which caused the histone deacetylation and subsequent transcriptional inhibition of miR‐326 gene. miR‐326 deficiency induced the stimulation of SMO/Hedgehog pathway and promoted the proliferation and invasion of 143B and MG63 cells as well as the growth and metastasis in nude mice. SP1/HDAC1 caused the transcriptional inhibition of miR‐326 gene by promoting histone deacetylation; miR‐326 deficiency conversely stimulated SMO/Hedgehog pathway that was responsible for the proliferation and metastasis of OS.

Mex3a interacts with LAMA2 to promote lung adenocarcinoma metastasis via PI3K/AKT pathway

Lung adenocarcinoma (LUAD) is the main subtype of lung cancer. In this study, we found that RBP Mex3a was significantly upregulated in LUAD tissues and elevated Mex3a expression was associated with poor LUAD prognosis and metastasis. Furthermore, we demonstrated that Mex3a knockdown significantly inhibited LUAD cell migration and invasion in vitro and metastasis in nude mice. Transcriptome sequencing indicated that Mex3a affected gene expression linked to ECM-receptor interactions, including laminin subunit alpha 2(LAMA2). RNA immunoprecipitation (RIP) assay revealed Mex3a directly bound to LAMA2 mRNA and Mex3a increased the instability of LAMA2 mRNA in LUAD cells. Furthermore, we discovered that LAMA2 was surprisingly downregulated in LUAD and inhibited LUAD metastasis. LAMA2 knockdown partially reverse the decrease of cell migration and invasion caused by Mex3a knockdown. In addition, we found that both Mex3a and LAMA2 could influence PI3K-AKT pathway, which are downstream effectors of the ECM-receptor pathway. Moreover, the reduced activation of PI3K-AKT pathway in caused by Mex3a depletion was rescued by LAMA2 knockdown. In conclusion, we demonstrated that Mex3a downregulates LAMA2 expression to exert a prometastatic role in LUAD. Our study revealed the prognostic and prometastatic effects of Mex3a in LUAD, suggesting that Mex3a can serve as a prognostic biomarker and a target for metastatic therapy.

LINC00941 promotes CRC metastasis through preventing SMAD4 protein degradation and activating the TGF-β/SMAD2/3 signaling pathway.

LINC00941 is a novel lncRNA that has been found to exhibit protumorigenic and prometastatic behaviors during tumorigenesis. However, its role in metastatic CRC remains unknown. We aimed to investigate the functions and mechanisms of LINC00941 in CRC metastasis. LINC00941 was shown to be upregulated in CRC, and upregulated LINC00941 was associated with poor prognosis. Functionally, LINC00941 promoted migratory and invasive capacities and accelerated lung metastasis in nude mice. Mechanistically, LINC00941 activated EMT in CRC cells, as indicated by the increased expression of key molecular markers of cell invasion and metastasis (Vimentin, Fibronectin, and Twist1) and simultaneous decreased expression of the main invasion suppressors E-cadherin and ZO-1. LINC00941 was found to activate EMT by directly binding the SMAD4 protein MH2 domain and competing with β-TrCP to prevent SMAD4 protein degradation, thus activating the TGF-β/SMAD2/3 signaling pathway. Our data reveal the essential role of LINC00941 in metastatic CRC via activation of the TGF-β/SMAD2/3 axis, which provides new insight into the mechanism of metastatic CRC and a novel potential therapeutic target for advanced CRC.

High expression of hexokinase 2 promotes lung cancer proliferation and metastasis

IntroductionHigh metabolic plasticity, as one of the hallmarks of multiple cancers, usually promotes cancer growth and metastasis. Therefore, metabolic enzymes could be selective targets in suppressing the growth and invasion of cancer cells. It is generally believed that hexokinase 2 (HK2) catalysing glucose into glucose-6-phosphate is the first step in glucose metabolism. It is unclear, however, if HK2 is involved in lung cancer (LC) proliferation and metastasis.Material and methodsTumours and adjacent tissue from LC patients were used to study the expression of HK2 by RT-PCR and western blot analysis. Several different LC cell lines were used to explore the oncogene function of HK2 via MTS and BrdU assay in vitro, as well as xenografts model and Lung metastasis model in vivo.ResultsHK2 was upregulated in primary LC tissue and metastatic foci. The expression of HK2 can be modulated by multiple mutations of oncogenes or tumour suppressors, including Kras, p53, and Keap1. Functionally, suppression of HK2 expression by shRNA transfection in LC cell lines hindered lactate production and therefore suppressed cell migration and invasion. The depletion of HK2 also sensitised the LC cells to cisplatin-induced apoptosis, suggesting that HK2 also mediated the chemoresistance in LC. Finally, our in vivo data indicated that stable knockdown of HK2 inhibited xenografted tumour growth, sensitized the tumour response to cisplatin treatment, and decreased the incidence of lung metastasis in nude mice after tail vein injection.ConclusionsWe demonstrated that HK2 is required for LC cell growth and metastasis in vitro and in vivo, and for its relationship between multiple mutations in LC. Our results revealed that HK2 promotes LC cell proliferation and metastasis in various mutation backgrounds of LC cells, indicating that HK2 is a high-potential therapy target for LC treatment. Our data provide strong evidence that HK2 plays an important role in promoting LC disease progression, and it may be a promising target for lung cancer therapy.

Upregulation of ARHGAP30 attenuates pancreatic cancer progression by inactivating the \u03b2-catenin pathway

BackgroundPancreatic cancer is a highly malignant gastrointestinal cancer that can widely metastasize during the early stage of disease, and it is associated with one of the worst prognoses among cancers. In this study, we aimed to investigate the function of Rho GTPase-activating protein 30 (ARHGAP30) in pancreatic cancer cells and thus propose a novel therapy for pancreatic cancer.MethodsARHGAP30 expression in tumor tissues from patients with pancreatic cancer as well as cell lines was detected using immunohistochemistry (IHC), real-time polymerase chain reaction, and western blotting. Cell proliferation, transwell, and apoptosis assays were performed and the levels of related proteins were determined after ARHGAP30 knockdown or overexpression. Additionally, in vivo experiments were performed on nude mice.ResultsARHGAP30 expression was found to be significantly increased in tumor tissues from patients with pancreatic cancer as well as in pancreatic cancer cell lines. IHC and prognostic analyses indicated that patients with high ARHGAP30 expression had a good prognosis. ARHGAP30 overexpression significantly decreased pancreatic cancer cell proliferation and metastasis; promoted apoptosis; reduced β-catenin, B-cell lymphoma 2 (Bcl-2), matrix metalloproteinase-2 (MMP2), and MMP9 expression; and increased Bcl-2-associated X protein (Bax) and cleaved caspase-3 expression. ARHGAP30 knockdown elicited the opposite effects. The effects of ARHGAP30 knockdown were potently attenuated by the β-catenin inhibitor XAV939. ARHGAP30 knockdown-induced RHOA activity was potently attenuated by the RHOA inhibitor CCG1423. In vivo, ARHGAP30 overexpression significantly inhibited lung metastasis in nude mice and increased the survival of mice with lung metastases.ConclusionsOur findings indicate that ARHGAP30 may function as a tumor suppressor in pancreatic cancer progression by regulating the expression of related genes and the β-catenin pathway.

Patient-derived pancreatic tumour organoids identify therapeutic responses to oncolytic adenoviruses.

BackgroundPancreatic patient–derived organoids (PDOs) are a well-established model for studying pancreatic ductal adenocarcinoma (PDAC) carcinogenesis and are potential predictors of clinical responses to chemotherapy. Oncolytic virotherapy is envisioned as a novel treatment modality for pancreatic cancer, and candidate viruses are being tested in clinical trials. Here, we explore the feasibility of using PDOs as a screening platform for the oncolytic adenovirus (OA) response.MethodsOrganoids were established from healthy pancreas and PDAC tissues and assessed for infectivity, oncoselectivity, and patient-dependent sensitivity to OA. Antitumour effects were studied in vivo in organoid xenografts. Further evaluation of oncolytic responses was conducted in organoids derived from orthotopic models or metastastic tissues.FindingsOncolytic adenoviruses display good selectivity, with replication only in organoids derived from PDAC tumours. Furthermore, responses of PDOs to a set of OAs reveal individual differences in cytotoxicity as well as in synergism with standard chemotherapy. Adenoviral cytotoxicity in PDOs is predictive of antitumour efficacy in a subcutaneous xenograft setting. Organoids from orthotopic tumours and metastases in nude mice mirror the viral preference of PDOs, indicating that PDO sensitivity to OAs could be informative about responses in both primary tumours and metastatic foci.InterpretationOur data imply that pancreatic PDOs can serve as predictive tools for screening for sensitivity to OA.

Transient NK Cell Depletion Facilitates Pulmonary Osteosarcoma Metastases After Intravenous Inoculation in Athymic Mice.

Two thirds of metastatic osteosarcoma patients die within 5 years of diagnosis. Improved experimental models of osteosarcoma metastasis will facilitate the development of more effective therapies. Intravenous cancer cell injection can produce lung metastases in nude mice, but this "experimental metastasis" technique has been predominantly applied to a single osteosarcoma cell line (143B) and required injection of 1-2 million cells. Using two human osteosarcoma cell lines, we discovered that transient Natural Killer cell depletion dramatically enhanced the efficiency of experimental pulmonary osteosarcoma metastasis. This technique for modeling osteosarcoma metastasis may enable the identification of better treatments for this aggressive cancer.

The PI3K/mTOR dual inhibitor GSK458 potently impedes ovarian cancer tumorigenesis and metastasis.

The PI3K/AKT/mTOR pathway is one of the most highly activated cellular signaling pathways in advanced ovarian cancer. Although several PI3K/AKT/mTOR inhibitors have been developed to treat various types of cancer, the antitumor efficacy of many of these compounds against ovarian cancer has remained unclear. Here, we tested and compared a panel of 16 PI3K/AKT/mTOR inhibitors (XL765, Miltefosine, Rapamycin, CCI-779, RAD001, FK506, XL147, GSK2110183, IPI-145, GSK2141795, BYL719, GSK458, CAL-101, XL765 analogue SAR245409, Triciribine, and GDC0941) that have entered clinical trials for antitumor activity against ovarian cancer, as well as the front line drug, paclitaxel. Antitumor efficacy was measured in both ovarian cancer cell lines and patient-derived ovarian primary tumor cell lines in vitro and in vivo. We identified the PI3K/mTOR dual inhibitor GSK458 as a potent inhibitor of proliferation in all cell lines tested at half maximal inhibitory concentrations (IC50) of approximately 0.01-1 µM, a range tens to hundreds fold lower than that of the other PI3K/AKT/mTOR inhibitors tested. Additionally, GSK458 showed the highest inhibitory efficacy against ovarian cancer cell migration. GSK458 also inhibited tumor growth and metastasis in nude mice intraperitoneally engrafted with SKOV3 cells or a patient-derived tumor cell xenograft (PDCX). Importantly, the inhibitory efficiency of GSK458 on cell proliferation and migration both in vitro and in vivo was comparable to that of paclitaxel. Mechanistically, the anti-tumor activity of GSK458 was found to be associated with inactivation of AKT and mTOR, and induction of cell cycle arrest at the G0/G1 phase. Based on our results, we conclude that GSK458 may serve as an attractive candidate to treat ovarian cancer.

PTGES/PGE2 signaling links immunosuppression and lung metastasis in Gprc5a-knockout mouse model

Chronic inflammation has been linked to promotion of tumorigenesis and metastasis in lung. However, due to lack of a relevant animal model for characterization, the underlying mechanism remains elusive. Lung tumor suppressor gene Gprc5a-knockout (ko) mice are susceptible to lung inflammation, tumorigenesis and metastasis, which resembles the pathological features in human patients. Here, we showed that PTGES/PGE2 signaling was highly associated with lung tumorigenesis and metastasis in Gprc5a-ko mice. Interestingly, Ptges-knockout in mouse lung tumor cells, although reduced their stemness and EMT-like features, still formed tumors and lung metastasis in immune-deficient nude mice, but not in immune-competent mice. This suggests that the major role of PTGES/PGE2 signaling in tumorigenicity and lung metastasis is through immunosuppression. Mechanistically, PTGES/PGE2 signaling intrinsically endows tumor cells resistant to T-cell cytotoxicity, and induces cytokines extrinsically for MDSC recruitment, which is crucial for suppression of T-cell immunity. Importantly, targeting PGE2 signaling in Gprc5a-ko mice by PTGES inhibitor suppressed MDSC recruitment, restored T cells, and significantly repressed lung metastasis. Thus, PTGES/PGE2 signaling links immunosuppression and metastasis in an inflammatory lung microenvironment of Gprc5a-ko mouse model.

MFAP2 is overexpressed in gastric cancer and promotes motility via the MFAP2/integrin \u03b15\u03b21/FAK/ERK pathway

Gastric cancer (GC) is one of the most common malignancies and its prognosis is extremely poor. This study identifies a novel oncogene, microfibrillar-associated protein 2 (MFAP2) in GC. With integrative reanalysis of transcriptomic data, we found MFAP2 as a GC prognosis-related gene. And the aberrant expression of MFAP2 was explored in GC samples. Subsequent experiments indicated that silencing and exogenous MFAP2 could affect motility of cancer cells. The inhibition of silencing MFAP2 could be rescued by another FAK activator, fibronectin. This process is probably through affecting the activation of focal adhesion process via modulating ITGB1 and ITGA5. MFAP2 regulated integrin expression through ERK1/2 activation. Silencing MFAP2 by shRNA inhibited tumorigenicity and metastasis in nude mice. We also revealed that MFAP2 is a novel target of microRNA-29, and miR-29/MFAP2/integrin α5β1/FAK/ERK1/2 could be an important oncogenic pathway in GC progression. In conclusion, our data identified MFAP2 as a novel oncogene in GC and revealed that miR-29/MFAP2/integrin α5β1/FAK/ERK1/2 could be an important oncogenic pathway in GC progression.