Antimetastatic and Antitumor Activities of Orally Administered NAX014 Compound in a Murine Model of HER2-Positive Breast Cancer.

The natural isoquinoline alkaloid Berberine (BBR) has been shown to possess several therapeutic effects, including anticancer activity. Different BBR derivatives have been designed and synthesized in order to obtain new compounds with enhanced anticancer efficacy. We previously showed that intraperitoneal (IP) administration of the BBR-derived NAX014 compound was able to counteract HER-2 overexpressing mammary tumors onset and progression in transgenic mice. However, the IP administration was found to induce organ toxicity at doses higher than 2.5 mg/Kg. In this study, we evaluated the effect of intragastric (IG) administration of 20 mg/kg of NAX014 on both safety and anticancer efficacy in HER-2/neu transgenic mice. Furthermore, cancer cell dissemination and migration, tumor cell senescence and immunological changes were examined. Our results demonstrated that IG NAX014 administration delayed the onset of mammary tumors with no negative effects on health and survival. NAX014 reduced HER-2 overexpressing BC cells migration in vitro and the frequency of lung metastasis in HER-2/neu transgenic mice. A statistically significant increase of senescence-associated p16 expression was observed in tumors from NAX014-treated mice, and the induction of cell senescence was observed in HER-2 overexpressing BC cells after in vitro treatment with NAX014. Although NAX014 did not modulate the presence of tumor-infiltrating lymphocytes, the level of circulating TNF-α and VEGF was found to be reduced in NAX014-treated mice. The overall results address the NAX014 compound as potential tool for therapeutic strategies against HER-2 overexpressing breast cancer.

Antitumor activity of NAX060: A novel semisynthetic berberine derivative in breast cancer cells.

Breast cancer (BC) is the most common malignancy and the most common cause of cancer death in elderly women. We recently demonstrated that innovative compounds structurally related to and semisynthetically derived from the plant alkaloid berberine represent a promising unexplored resource for novel therapeutic tools in BC therapy. In this study, we analyzed the effectiveness of new 13-dichlorophenylalkyl berberine semisynthetic derivatives (NAX060, NAX103, NAX111, and NAX114) on the viability of BC cell lines. Our results demonstrated that the new compounds effectively inhibited the growth of a variety of human BC cell lines. In particular, the viability of HER-2 overexpressing SK-BR-3 cells was significantly reduced by the treatment with NAX060, the most active compound, in a dose and time-dependent manner. In the same tumor cell line, NAX060 induced a strong increase in sub-G1 population while G0/G1 and G2/M phase cells remarkably decreased. NAX060 withdrawal after 72 h of treatment resulted in an irreversible cell proliferation arrest and increasing cell death. Real-time PCR analyses showed that NAX060 induced the expression of some cell-cycle checkpoint molecules involved in cell senescence such as p21WAF1, p27, p16INK4a, and PAI-1. Furthermore, the HER-2 protein expression and phosphorylation, as well as the level of heparanase expression, were remarkably reduced on SK-BR-3 cells. NAX060 was effective also on HER-2 negative tumor cells, and, in particular, on human triple-negative MDA-MB-231 cells. These data suggest a potential therapeutic effect of NAX060 compound in the management of BC malignancies. Interestingly, NAX060 may represent a new useful tool also in triple-negative BC. © 2018 BioFactors, 44(5):443-452, 2018.

Antiangiogenic and antitumor activities of berberine derivative NAX014 compound in a transgenic murine model of HER2/neu-positive mammary carcinoma.

Berberine (BBR) is a natural isoquinoline alkaloid with proven antiangiogenic and anticancer activities. We recently demonstrated that BBR and its synthetic derivative 13-(4-chlorophenylethyl)berberine iodide, NAX014, exert antiproliferative activity against HER2-overexpressing breast cancer cells, inducing apoptosis, modulating the expression of cell cycle checkpoint molecules involved in cell senescence, and reducing both HER2 expression and phosphorylation on tumor cells. In this study, we examined the anticancer properties of BBR and NAX014 in a transgenic mouse model which spontaneously develops HER2-positive mammary tumors. Repeated intraperitoneal injections of a safety dose (2.5mg/kg) of NAX014 delayed the development of tumors, reducing both the number and size of tumor masses. In vivo sidestream dark field videomicroscopy revealed a significant lower vessel density in mammary tumors from NAX014-treated mice in comparison with the control group. Immunohistochemical evaluation using CD34 antibody confirmed the reduced vessel density in NAX014 group. Statistically significant increase of senescence associated ß-galactosidase and p16 expression, and reduced expression of heparanase were observed in tumors from NAX014-treated mice than in tumors from control animals. Finally, NAX014 treatment decreased the level of perforine and granzyme mRNA in mammary tumors. Berberine did not show any statistically significant modulation in comparison with control mice. The results of the present study indicate that NAX014 is more effective than BBR in exerting anticancer activity delaying the development of mammary tumors in mice transgenic for the HER-2/neu oncogene. The antitumor efficacy of NAX014 is mainly related to its effect on tumor vascular network and on induction of tumor cell senescence.

Antitumor effect of novel berberine derivatives in breast cancer cells.

Breast cancer is the most common malignancy and the most common cause of cancer death in elderly women. Chemoprevention with dietary compounds and their synthetic analogs has emerged as an attractive strategy to prevent carcinogenic progression to invasive cancer. In this study, we investigated the efficacy of some new synthetic derivatives of berberine, a phytochemical isolated from Barberry and other plants, to induce growth arrest of HER-2/neu overexpressing SK-BR-3 breast cancer cells. Supplementation with berberine or with the synthetic derivatives NAX012, NAX013, NAX014, and NAX035 exerted a dose- and time-dependent inhibition of SK-BR-3 cell viability, with a greater effectiveness of NAX012 and NAX014 compounds with respect to berberine. This cytotoxic effect was related to an increased number of apoptotic cells that reached 71.6% and 68.4% after 72 h treatment with 50 µM of NAX012 and NAX014, respectively, compared with 44.2% of berberine. Real-time PCR analyses showed that berberine, NAX012 and NAX014 compounds increased the expression of some cell-cycle checkpoint molecules involved in cell senescence such as p53, p21(WAF1) , p16(INK4a) , and PAI-1, already after 24 h of 50 µM treatments. Furthermore, berberine, NAX012 and NAX014, all reduced both HER-2/neu expression and phosphorylation on tumor cells, the NAX014 compound showing the higher effectiveness. These results provide novel information on the mechanisms involved in the anticancer effects of berberine and demonstrate the greater effectiveness of NAX012 and NAX014 analogs in inducing apoptosis and cellular senescence in HER-2/neu overexpressing tumor cell lines.

Human and murine macrophages mediate activation of MEN 4901/T-0128: a new promising camptothecin analogue-polysaccharide conjugate.

MEN 4901/T-0128 is a new cytotoxic prodrug constituted by the camptothecin analogue T-2513 bound to carboxymethyl dextran through a triglycine linker. MEN 4901/T-0128 was designed to target the active camptothecin at the tumour site. MEN 4901/T-0128 is weakly cytotoxic in vitro and thus T-2513 must be released from the conjugate to become active. Here, we demonstrated that human purified cathepsin B releases T-2513 from MEN 4901/T-0128 at pH values ranging from 3 to 5. pH dependency of this reaction suggests that cleavage of the linker should mainly occur in the lysosomes. As elevated cathepsin B activity has been described in macrophages, human tumour monocytic THP-1 cells differentiated into macrophage-like cells were used to study the cellular mechanisms responsible for MEN 4901/T-0128 antitumour activity. Here, we show that differentiated THP-1 internalizes MEN 4901/T-0128 efficiently in a time-dependent and concentration-dependent manner. After phagocytosis, THP-1 cells can cleave the prodrug and release T-2513 in the media. On the contrary, undifferentiated THP-1 cells or pancreatic ASPC-1 tumour cells, although expressing high levels of cathepsin B, are much less efficient in the release of cytotoxic moieties in the culture media. Moreover, normal murine macrophages, recovered from the peritoneal cavity or from the spleen, when activated (in vitro by 100 ng/ml phorbol 12-myristate-13-acetate and in vivo by 300 microl of 3% w/v thioglycollate solution), were able to release (after incubation with 10 microg/ml MEN 4901/T-0128) cytotoxic moieties in the culture supernatant, in an amount sufficient to kill human carcinoma A2780 cells. Thus, we suggest that tumour-associated macrophages may play a key role in the uptake of MEN 4901/T-0128, cleavage and local release of active moiety T-2513. This mechanism should support a tumour targeting of the cytotoxic moieties, allowing an improved antitumour efficacy/safety ratio for MEN 4901/T-0128.

NF-kappaB activation contributes to anthracycline resistance pathway in human ovarian carcinoma cell line A2780.

The development of chemoresistance is a major obstacle for successful anticancer therapy. Understanding the molecular mechanisms leading to chemoresistance is a rational step to improve the therapeutic efficacy of cytotoxic drugs. Since anthracyclines play an important role in cancer chemotherapy, we have generated a human ovarian tumor cell line resistant to sabarubicin (MEN 10755), the newest anthracycline molecule in clinical development. Expression of the transporter protein MRP that affected sabarubicin uptake, and a reduced DNA topoisomerase II content in A2780/saba cells was observed. Since the poisoning of DNA topoisomerase II results in DNA damage, which is a critical signal for NF-kappaB activation, we explored if this transcription factor has a role in the chemoresistance to anthracyclines. We showed a reduced NF-kappaB activation in the resistant cell line. Moreover, qualitative changes in NF-kappaB dimer formation between the two cell lines were observed. In agreement with the hypothesis of a role of NF-kappaB in mediating drug resistance, we showed that the pharmacological inhibition of NF-kappaB activation attenuated drug resistance in A2780/saba cells whereas it had no effect in A2780 cells. Altogether, these findings show that anthracycline resistance in A2780 cell lines is due to the coexpression of several molecular mechanisms.

MEN15658: a new promising anti-tumoral drug active on resistant tumor cells.

We describe the identification of MEN15658, a molecule characterized by a promising cytotoxic effect against human tumor cell lines, including platinum- and anthracycline-resistant ovarian carcinoma. MEN15658 induces p53 accumulation, and activation of gadd-45, p21, c-fos and bcl-2 family genes in human ovarian carcinoma A2780 cell line. The compound causes a block in S phase of the cell cycle, inducing apoptotic cell death, thus suggesting an involvement of DNA damage in the MEN15658 effect on tumor cells. The anti-tumoral activity observed against the human ovarian carcinoma A2780 cell line xenotransplanted in nude mice makes this compound a new promising anti-tumoral drug.