XPNPEP2 is overexpressed in cervical cancer and promotes cervical cancer metastasis.

XPNPEP2 is a proline hydrolytic enzyme that hydrolyzes several biologically active peptides and causes a loss of substrate activity. However, its function in cancer is still unknown. Our study showed that XPNPEP2 expression was significantly upregulated in cervical cancer tissues compared with normal cervical tissues and cervical intraepithelial neoplasm tissues. Statistical analysis showed that XPNPEP2 expression was associated with the International Federation of Gynecology and Obstetrics stage and lymph node metastasis. Overexpression of XPNPEP2 in SiHa and HeLa cells promoted cell invasion and migration without affecting cell proliferation and apoptosis. Mechanistically, we found that XPNPEP2 facilitated cervical cancer cell invasion and migration by inducing epithelial-mesenchymal transition. Furthermore, we demonstrated that XPNPEP2 had significant effects on the metastasis of xenografted tumors in vivo. Collectively, our findings identify the novel function of XPNPEP2 in the metastasis of cervical cancer and suggest that XPNPEP2 could be a novel potential therapeutic target for the treatment of cervical cancer.

SPECT imaging of interleukin-6 receptor in ovarian tumor xenografts with a novel radiotracer of 99mTc-HYNIC-Aca-LSLITRL.

Growing evidences have shown that the IL-6/IL-6R signal pathway promotes the tumor growth, angiogenesis, invasion and migration in various cancers, especially for epithelial ovarian cancer. Hence, including anti-IL-6 antibody (Siltuximab) and anti-IL-6R antibody (Tocilizumab), more and more therapeutic drugs targeting IL-6/IL-6R pathway were developed to block their activity. The molecular imaging of IL-6R is a significant factor for predicting tumor response to IL-6/IL-6R targeted drugs. However, few probes targeting IL-6R were designed and used for the specific detection. The purpose of this study was to develop and evaluate a novel radiotracer, (99m)Tc-HYNIC-Aca-LSLITRL, for SPECT imaging of interleukin-6 receptor. The expression of IL-6R was determined by western blot, immunofluorescence and immunohistochemistry. HYNIC-Aca-LSLITRL and HYNIC-Aca-TLQASIL were synthesized, and then were labeled with 99mTc. The stability and the cell-binding assay were performed. Ovarian tumor xenografts were established and subjected to SPECT imaging after injection of these two radiopharmaceuticals with or without excess primary peptides. The biodistribution of these two radiotracers was performed in nude mice bearing C13K tumors. (99m)Tc-HYNIC-Aca-LSLITRL and (99m)Tc-HYNIC-Aca-TLQASIL were obtained in >95 % labeling yield with favorably stability. In vitro studies demonstrated that the interleukin-6 receptor was overexpressed in ovarian cancer C13K cells. The SPECT imaging of interleukin-6 receptor and biodistribution studies showed that (99m)Tc-HYNIC-Aca-LSLITRL had higher tumor uptake and significantly lower kidney accumulation compared to (99m)Tc-HYNIC-Aca-TLQASIL. (99m)Tc-HYNIC-Aca-LSLITRL could be a promising agent for SPECT imaging of interleukin-6 receptor of ovarian cancer especially for those anti-IL-6R drugs under clinical trials, such as tocilizumab.

XPNPEP2 is associated with lymph node metastasis in prostate cancer patients.

As we reported in our previous studies, TMTP1, a tumor-homing peptide, selectively targets highly metastatic tumors and their metastatic foci. Aminopeptidase P2 (XPNPEP2) is a receptor for TMTP1 tumor-homing peptide. However, the biological and clinical significance of Aminopeptidase P2 in human cancers remains unknown. In this study, the high-density multiple organ tumor tissue array was employed for the analysis of XPNPEP2 expression profiles in human specimens. The results showed that XPNPEP2 was moderately expressed in the normal prostate tissues, but significantly decreased in the prostate cancer. Hence we used TCGA, IHC, and ELISA to further analyze the expression of XPNPEP2 in tissues and serum of prostate cancer patients. In general, XPNPEP2 expression was lower in prostate cancer tissue than in normal prostate tissue, but was higher in prostate cancer tissues with local invasion and LN metastasis than in tissues with localized Pca. Western blot clarified XPNPEP2 had a secreted form in the serum. Then the serums of 128 Pca patients, 70 healthy males and 40 prostate hyperplasia patients were obtained for detecting serum XPNPEP2 levels.The results indicated that the concentration of XPNPEP2 in serums of Pca patients with LN metastasis (142.7 ± 14.40 ng/mL) were significantly higher than levels in Pca patients without LN metastasis (61.63 ± 5.50 ng/mL) (p < 0.01). An ROC analysis revealed that the combination of PSA and XPNPEP2 was more efficient than PSA or XPNPEP2 alone for predicting LN metastasis, especially for Pca patients with low serum PSA levels. In summary, serum XPNPEP2 levels when combined with PSA levels may result in increased sensitivity for predicting LN metastasis in Pca patients, especially for patients with low serum PSA levels.

TMTP1-modified Indocyanine Green-loaded Polymeric Micelles for Targeted Imaging of Cervical Cancer and Metastasis Sentinel Lymph Node in vivo.

Metastasis is one of the most threatening aspects of cervical cancer. We developed a method to intraoperatively map the primary tumor, metastasis and metastatic sentinel lymph nodes (SLNs), providing real-time intraoperative guidance in cervical cancer. Methods: TMTP1, a tumor metastasis targeting peptide, was employed to modify the indocyanine green (ICG)-loaded poly (ethylene glycol)- poly (lactic-co-glycolic acid) (PEG-PLGA) micelles. The cervical cancer subcutaneous tumor model and lung metastasis model were established to determine the active targeting of ICG-loaded TMTP1-PEG-PLGA micelles (ITM) for the primary tumor and occult metastasis of cervical cancer. Human cervical cancer HeLa cells engineered by firefly luciferase were injected into the right hocks of BALB/c nude mice to develop the SLN metastasis model. The ITM and control ICG-loaded PEG-PLGA micelles (IM) were injected into the right hind footpads in the SLN metastasis model, and the migration and retention of micelles were recorded under near-infrared fluorescence. K14-HPV16 transgenic mice were also used to detect the image capability of ITM to target cancerous lesions. Results: ITM could actively target imaging of the primary tumor and cervical cancer metastasis. ITM quickly diffused from the injection site to SLNs along lymphatic capillaries and remained in the SLNs for 12 h. Moreover, ITM specifically accumulated in the tumor metastatic SLNs (T-SLNs), which could be successfully distinguished from normal SLNs (N-SLNs). Conclusion: ITM could achieve active targeting of the primary tumor, metastasis and T-SLNs, providing precise and real-time intraoperative guidance for cervical cancer.

MMP26: A potential biomarker for prostate cancer.

The application of prostate-specific antigen (PSA) in the screening and diagnosis of prostate cancer (PCa) has improved the clinical management of PCa patients. However, the PSA assay has been faced with criticism due to its potential association with over-diagnosis and subsequent overtreatment of indolent patients. Matrix metalloproteinase-26 (MMP26) is a member of matrix metalloproteinases (MMPs) and has been reported to be highly expressed in many cancers. This investigation evaluated the potential of serum MMP26 as a biomarker for PCa. The level of serum MMP26 was measured by enzyme-linked immunosorbent assay (ELISA) in 160 subjects including PCa group (n=80), benign prostatic hyperplasia (BPH) group (n=40) and control group (n=40). Furthermore, we evaluated the expression of MMP26 in tissues by immunohistochemistry. The results showed the serum MMP26 levels were significantly higher in PCa group than in BPH group and control group. Similarly, the MMP26 protein was positive in PCa tissues and negative in BPH tissues and control tissues. In conclusion, these results suggested MMP26 could be used as a potential serum biomarker in the diagnosis of PCa.

Human CAFs promote lymphangiogenesis in ovarian cancer via the Hh-VEGF-C signaling axis.

Cancer-associated fibroblasts (CAFs) play a pivotal role in the development and progression of many human cancers. Recent studies have shown that Hedgehog (Hh) signalling modulates the stromal microenvironment and prepares a suitable niche for tumour metastasis. However, the detailed molecular mechanisms underlying CAF-mediated lymphangiogenesis have not been fully elucidated. Therefore, our goal is to illustrate whether Hh ligands can activate Hh signalling in CAFs in a paracrine fashion and elucidate the effect of CAFs on lymphangiogenesis. We determined here that Sonic Hedgehog (SHH) secreted by ovarian cancer (OC) cells activated Hh signalling in CAFs and promoted the proliferation of CAFs. Moreover, we co-injected SHH-overexpressing OC cells and CAFs in a xenograft model and found that the CAFs accelerated tumourigenesis and lymphangiogenesis in OC. Mechanistically, we found that SHH secreted by the OC cells induced VEGF-C expression in CAFs. Inhibition of Hh signalling in CAFs decreased VEGF-C expression and diminished the positive role of CAFs in supporting tumourigenesis and lymphangiogenesis in a murine xenograft model. Our results demonstrate that CAFs constitute a supportive niche for cancer lymphangiogenesis via the Hh/VEGF-C signalling axis and provide evidence for the clinical application of Hh inhibitors in the treatment of OC.