Metastasis is the major cause of death in breast cancers. MMPs play a key role in tumor microenvironment that facilitates metastasis. The existing researches suggest that the high expression of gelatinase A and B (MMP2 and MMP9) promote the metastasis of breast cancer. Therefore, gelatinase inhibitor can effectively suppress tumor metastasis. However, at present, there is no dramatically effective gelatinase inhibitor against breast cancer. We screened gelatinase inhibitor among Chinese herbal medicine by molecular docking technology; investigated the proliferation, migration and invasion of MDA-MB-231 human breast cancer cell line and 4T1 mouse breast cancer cell line in response to the treatment with the screened inhibitor by wound assay, invasion assay and gelatin zymography; then further examined the effects of inhibitor on allograft mammary tumors of mice by immunohistochemistry. We successfully screened an Chinese herbal medicine-Plantamajoside(PMS)-which can reduce the gelatinase activity of MMP9 and MMP2. In vitro, PMS can inhibit the proliferation, migration and invasion of MDA-MB-231 human breast cancer cell line and 4T1 mouse breast cancer cell line by decreasing MMP9 and MMP2 activity. In vivo, oral administration of PMS to the mice bearing 4T1 cells induced tumors resulted in significant reduction in allograft tumor volume and weights, significant decrease in microvascular density and significant lower lung metastasis rate. Our results indicate that as a promising anti-cancer agent, PMS may inhibit growth and metastasis of breast cancer by inhibiting the activity of MMP9 and MMP2.

Mammary gland tumor is the most common spontaneous tumor in intact female dogs, and its poor prognosis remains a clinical challenge. Ivermectin, a well-known anti-parasitic agent, has been implicated as a potential anticancer agent in various types of human cancer. However, there are no reports evaluating the antitumor effects of ivermectin in canine mammary tumor. Here, we investigated whether ivermectin was able to inhibit canine mammary tumor development and explored the related mechanisms. Ivermectin inhibited the growth of canine mammary tumor cell lines in a dose- and time-dependent manner. The antitumor effects induced by ivermectin were associated with cell cycle arrest at G1 phase via down-regulation of CDK4 and cyclin D1 expression, with no significant induction of apoptosis. Furthermore, significantly reduced β-catenin nuclear translocation was observed after treatment with ivermectin, resulting in the inactivation of WNT signaling. Consistent with the results in vitro, a significant suppression of tumor growth by ivermectin was observed in canine mammary tumor xenografts. Ivermectin, as a promising anti-cancer agent, inhibits the growth of canine mammary tumor by regulating cell cycle progression and WNT signaling.

Curcumin is a natural acidic polyphenol extracted from turmeric with a wide range of biological and pharmacological effects. However, the application of curcumin for animal production and human life is limited by a low oral bioavailability. In this study, natural curcumin was prepared for the curcumin β-cyclodextrin inclusion complex (CUR-β-CD), curcumin solid dispersion (CUR-PEG-6000), and curcumin phospholipid complex (CUR-HSPC) using co-precipitation, melting, and solvent methods, respectively. Curcumin complex formations were monitored using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) techniques via the shifts in the microscopic structure, molecular structure, and crystalline state. Subsequently, twenty-four female beagle dogs were randomly divided into four groups to receive unmodified curcumin and three other curcumin preparations. The validated UPLC–MS assay was successfully applied to pharmacokinetic and bioavailability studies of curcumin in beagle dog plasma, which were collected after dosing at 0 min (predose), 5 min, 15 min, 30 min, 40 min, 50 min, 1.5 h, 3 h, 4.5 h, 5.5 h, 6 h, 6.5 h, 9 h, and 24 h. The relative bioavailabilities of CUR-β-CD, CUR-PEG-6000, and CUR-HSPC were 231.94%, 272.37%, and 196.42%, respectively. This confirmed that CUR-β-CD, CUR-HSPC, and especially CUR-PEG-6000 could effectively improve the bioavailability of curcumin.

Metastasis is the leading cause of death in breast cancer patients. CD73, also known as ecto-5′-nucleotidase, plays a critical role in cancer development including metastasis. The existing researches indicate that overexpression of CD73 promotes growth and metastasis of breast cancer. Therefore, CD73 inhibitor can offer a promising treatment for breast cancer. Here, we determined whether tiamulin, which was found to inhibit CD73, was able to suppress breast cancer development and explored the related mechanisms. We firstly measured the effect of tiamulin hydrogen fumarate (THF) on CD73 using high performance liquid chromatography (HPLC). Then, we investigated cell proliferation, migration and invasion in MDA-MB-231 human breast cancer cell line and 4 T1 mouse breast cancer cell line treated with THF by migration assay, invasion assay and activity assay. Besides, we examined the effect of THF on syngeneic mammary tumors of mice by immunohistochemistry. Our data demonstrated that THF inhibited CD73 by decreasing the activity instead of the expression of CD73. In vitro, THF inhibited the proliferation, migration and invasion of MDA-MB-231 and 4 T1 cells by suppressing CD73 activity. In vivo, animal experiments showed that THF treatment resulted in significant reduction in syngeneic tumor growth, microvascular density and lung metastasis rate. Our results indicate that THF inhibits growth and metastasis of breast cancer by blocking the activity of CD73, which may offer a promising treatment for breast cancer therapy.