Design, synthesis, and evaluation of a novel series of mono-indolylbenzoquinones derivatives for the potential treatment of breast cancer

Gene therapy for colon cancer by adeno-associated viral vector-mediated transfer of survivin Cys84Ala mutant

In Vivo Evidence for the Role of CD44s in Promoting Breast Cancer Metastasis to the Liver

Research Objectives and Rationale: We previously presented (2023 SABCS) that monotherapy with the RAR gamma agonist IRX5010 inhibits tumor growth in the triple negative breast cancer EMT-6 syngeneic mouse model; and in a human Her2+ JIMT-1 breast cancer xenograft mouse model. Growth inhibitory effects of IRX5010 in both models were accompanied by increased tumor infiltrating effector memory T-cells. We presented (2024 FASEB Retinoids Conference), effects of monotherapy with IRX5010 on inhibition of tumor growth accompanied by development of tumor infiltrating effector memory T-cells in mouse models of lung, (Lewis Lung Cancer); colorectal (MC38) and prostate cancers (MyC-CaP). We observed in these studies inhibition of tumor infiltration by myeloid derived suppressor cells, suggesting that combination treatment with IRX5010 and checkpoint inhibitors could increase inhibition of tumor growth. We now present data on IRX5010 treatments with anti-PD-1 or anti-PDL-1 monoclonal antibody checkpoint inhibitors in an EMT-6 triple negative breast cancer model. Experimental Methods: EMT-6 cells were injected into Balb/c mice and allowed to grow to 50-150 mm3. Then treatments were started and maintained until tumors grew to 1500 mm3. Treatment was administered as daily oral doses of IRX5010 at 10 mg/kg/day, or vehicle. Murine monoclonal anti-PD-1 or anti-PDL-1 antibodies were injected ip every three days at 10 mg/kg. Tumor sizes were assessed by calipers every three days. Toxicity assessment was done by weighing the mice every three days. Flow cytometry of harvested tumors for tumor infiltrating T-cell subtypes, and myeloid derived suppressor cells was done at study end. Results: Monotherapy with either IRX5010 or murine anti-PDL-1 monoclonal antibody had substantial inhibitory effects relative to vehicle on tumor growth in the syngeneic EMT-6 triple negative breast cancer model; -61% for IRX5010, and -75% for murine anti-PDL-1. Monotherapy with murine anti-PD-1 had modest inhibitory effect on tumor growth, -14%. Combination treatment with IRX5010 plus murine anti-PDL-1 had an additive effect resulting in 84% inhibition of tumor growth relative to vehicle, a 9% additional inhibition of tumor growth compared to monotherapy with anti-PDL-1 alone. Combination treatment with IRX5010 plus murine anti-PD-1 had a modest additive effect, resulting in -65% inhibition of tumor growth relative to vehicle, a 4% additional inhibition of tumor growth compared to monotherapy with IRX5010. Flow cytometry for T-cells subsets and myeloid derived suppressor cells was performed. These results are pending at the time of submission of this abstract. The data will be presented at the symposium. Conclusions: Treatment of the EMT-6 murine model of triple negative breast cancer with the RAR gamma selective agonist compound IRX5010 plus the checkpoint inhibitor monoclonal murine anti-PDL-1 resulted in 84% inhibition of tumor growth, a 9% increase of inhibitory treatment effect over anti-PDL-1 alone. Combination treatment with IRX5010 with monoclonal anti-PD-1 had only modest additive effects on inhibition of EMT-6 tumor growth. All treatment regimens were well tolerated as assessed by change in weight. These findings are the first demonstration of additive effects of combination treatment with an RAR gamma nuclear receptor agonist and an anti-PDL-1 monoclonal antibody checkpoint inhibitor in a triple negative breast cancer mouse model. They support future translation of combination treatment with IRX5010 plus an anti-PDL-1 monoclonal antibody checkpoint inhibitor into clinical trials in triple negative breast cancer patients. Citation Format: Martin Sanders, Vidyasagar Vuligonda. The RAR gamma nuclear receptor agonist IRX5010 has combination inhibitory effects with an anti-PDL-1 checkpoint inhibitor on the growth of EMT-6 triple negative breast cancer [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P2-02-03.

The role of opioids in cancer progression.

Abstract: There are considerable direct evidences to support that calcium binding protein ANX A2 is a potential target for aggressive breast cancer. The most compelling evidence is based on the fact that ANX A2 overexpress specifically in aggressive triple negative human breast cancer (TNBC) cell lines as well as in human breast cancer tissues. Previously, we and others have demonstrated a unique role of ANX A2 in cancer invasion including breast cancer. Moreover we demonstrated that anti-ANX A2 monoclonal antibody (anti-ANX A2mAb)-mediated immunoneutralization of ANX A2 inhibited invasive human breast growth in a xenograft model. We further evaluated long-term effect of multiple treatments of anti-ANX A2mAb and its mechanism of inhibition of human breast tumor growth. We now show that three treatments of anti-ANX A2mAb showed significant inhibition of breast tumor growth in immunodeficient mice and anti-tumor response was started from day 94. After treatments, we followed tumor growth for 172 days and our results demonstrated 67% inhibition of tumor growth without detectable adverse effects. Biochemical analysis demonstrated anti-ANX A2mAb treatment caused significant inhibition of tissue plasminogen activator (tPA) synthesis in the tumor microenvironment. This led to disruption of plasmin generation that consequently inhibited activation of MMP-9 and MMP-2. These results suggest that ANX A2 plays an important role in aggressive breast tumor growth by regulating proteolytic pathway in the tumor microenvironment. ANX A2 may represent a new target for the development of therapeutics for the treatment of aggressive breast cancer. Citation Format: Mahesh C. Sharma, George P. Tuszynski, Marc R. Blackman, Meena Sharma. Long-term efficacy and downstream mechanism of anti-Annexin A2 monoclonal antibody in a pre-clinical model of aggressive human breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 570.

Mitogen-activated protein kinase kinase 3 (MAP2K3) is a member of the dual specificity kinase group. Growing evidence links MAP2K3 to invasion and tumor progression. Here, we identify MAP2K3 as a transcriptional target of endogenous gain-of-function p53 mutants R273H, R175H, and R280K. We show that MAP2K3 modulation occurred at the mRNA and protein levels and that endogenous mutant p53 proteins are capable of binding to and activate the MAP2K3 promoter. In addition, we found that the studied p53 mutants regulate MAP2K3 gene expression through the involvement of the transcriptional cofactors NF-Y and NF-kappaB. Finally, functional studies showed that endogenous MAP2K3 knockdown inhibits proliferation and survival of human tumor cells, whereas the ectopic expression of MAP2K3 can rescue the proliferative defect induced by mutant p53 knockdown. Taken together, our findings define a novel player through which mutant p53 exerts its gain-of-function activity in cancer cells.

The aminobisphosphonate zoledronic acid has elicited significant attention due to its remarkable anti-tumoral activity, although its detailed mechanism of action remains unclear. Here, we demonstrate the existence of a nuclear GSK-3β-NFATc2 stabilization pathway that promotes breast and pancreatic cancer growth in vitro and in vivo and serves as a bona fide target of zoledronic acid. Specifically, the serine/threonine kinase GSK-3β stabilizes nuclear NFATc2 through phosphorylation of the serine-rich SP2 domain, thus protecting the transcription factor from E3-ubiquitin ligase HDM2-mediated proteolysis. Zoledronic acid disrupts this NFATc2 stabilization pathway through two mechanisms, namely GSK-3β inhibition and induction of HDM2 activity. Upon nuclear accumulation, HDM2 targets unphosphorylated NFATc2 for ubiquitination at acceptor lysine residues Lys-684/Lys-897 and hence labels the factor for subsequent proteasomal degradation. Conversely, mutagenesis-induced constitutive serine phosphorylation (Ser-215, Ser-219, and Ser-223) of the SP2 domain prevents NFATc2 from HDM2-mediated ubiquitination and degradation and consequently rescues cancer cells from growth suppression by zoledronic acid. In conclusion, this study demonstrates a critical role of the GSK-3β-HDM2 signaling loop in the regulation of NFATc2 protein stability and growth promotion and suggests that double targeting of this pathway is responsible, at least to a significant part, for the potent and reliable anti-tumoral effects of zoledronic acid.

The role of macrophages from rats treated with a streptococcal preparation (OK-432) for inhibition of syngeneic tumor growth was examined both in vivo and in vitro. Treatment of rats with OK-432 intraperitoneally resulted in a transient inhibition of ascites tumor growth and concomitant increase in survival time. Peritoneal exudate cells from these rats completely suppressed tumor growth when admixed with tumor cells and transferred subcutaneously to syngeneic recipient rats. No such effect was observed with tumor cells from saline-treated control rats. The macrophages were responsible for the neutralization of tumor growth, since the removal of adherent cells from peritoneal exudate cells of rats treated with OK-432 resulted in the abrogation of their antitumor activity. To further investigate the antitumor activity of macrophages, an in vitro cytotoxicity assay was carried out on several tumor cell lines. A complete target cell destruction was brought about by macrophages from the rats treated with OK-432 but not from the control animals. The tumor cytotoxicity mediated by macrophages activated with OK-432 was regarded as non-specific because they could damage all the target cell lines tested.

Metronomic Chemotherapy Enhances Antitumor Effects of Cancer Vaccine by Depleting Regulatory T Lymphocytes and Inhibiting Tumor Angiogenesis

Long-term efficacy and downstream mechanism of anti-annexinA2 monoclonal antibody (anti-ANX A2 mAb) in a pre-clinical model of aggressive human breast cancer

Adjuvant bisphosphonates in patients with breast cancer: does the potency matter?

An Antimetastatic Role for Decorin in Breast Cancer

BACKGROUND: The current sequential use of antibody-drug conjugates (ADCs) for metastatic breast cancer in clinics lacks preclinical evidence. There are no data to justify sequencing topoisomerase I (Topo1) payloads, such as sacituzumab govitecan (SG), trastuzumab deruxtecan (T-DXd), and datopotamab deruxtecan (Dato-DXd). As use of these ADCs expands in metastatic disease, resistance driven by shared payload mechanisms raises concerns about cross-resistance and cumulative toxicity. We hypothesized that switching to antibody-drug conjugates (ADCs) with distinct cytotoxic payloads could overcome Topo1 inhibitor resistance and restore therapeutic efficacy. To test this hypothesis, we utilized breast cancer cell line models with acquired resistance to Topo1 inhibitor-based ADCs and evaluated sequential treatment regimens incorporating ADCs with alternative payloads. MATERIALS AND METHODS: We utilized two T-DXd-resistant (T-DXd-R) HER2+ breast cancer cell lines (SUM190-TDXd-R, HCC1954-TDXd-R) and two SG-resistant (SG-R) triple-negative breast cancer (TNBC) cell lines (HCC1806-SG-R, MDA-MB-468-SG-R), along with their respective parental control cells. HER2 and Trop2 expression following chronic ADC exposure was evaluated by Western blotting and flow cytometry. ADC internalization was evaluated using endocytosis assays. To assess ADC and payload sensitivity, we performed sulforhodamine B (SRB) proliferation assays using a panel that included ADCs conjugated to Topo1-inhibitor (T-DXd, SG, Dato-DXd), Topo1-inhibiting payloads (DXd, SN38), microtubule-disrupting payloads (MMAF [Monomethyl auristatin F], MMAE [Monomethyl auristatin E]), and ADCs conjugated to tubulin inhibitors (T-DM1, trastuzumab-MMAF, sacituzumab-MMAF). In vivo efficacy studies were conducted using xenograft models derived from SUM190-TDXdR and HCC1806-SGR cells. RESULTS: HER2 expression was significantly reduced in T-DXd-R HER2+ breast cancer cells (p < 0.002), while Trop2 expression remained stable in both T-DXd-R and SG-R triple-negative breast cancer models, compared to parental cells. ADC internalization correlated directly with surface antigen levels (p < 0.01). Both resistant models showed reduced sensitivity not only to their respective ADCs but also to other Topo1 inhibitor-based ADCs and free Topo1-inhibiting payloads (p < 0.01 for all comparisons with parental controls). In contrast, microtubule-disrupting agents such as MMAE and MMAF, as well as ADCs containing MMAF, demonstrated strong antitumor effects. In the T-DXd-R HER2+ breast cancer model, tumor growth inhibition was negligible with SG (not significant), but significant with T-DXd (50.4%, p < 0.0001), trastuzumab-MMAF (83.9%, p < 0.0001), and sacituzumab-MMAF (76.7%, p < 0.0001) compared to control. Similarly, in SG-R TNBC xenografts, SG had no significant effect, whereas sacituzumab-MMAF achieved 86.9% tumor growth inhibition (p < 0.0001) compared to 31.7% with Dato-DXd (not significant). CONCLUSIONS: This first preclinical report demonstrates that resistance to Topo1 inhibitor-based ADCs in breast cancer is primarily driven by payload-specific insensitivity rather than complete loss of target antigen expression. In contrast, switching to ADCs with distinct payloads, such as microtubule inhibitors (MMAF or MMAE), restored antitumor efficacy in tumors that had lost responsiveness to Topo1 inhibitor-based ADCs. These findings underscore the payload class as a critical determinant of ADC anti-cancer activity. We need to advance the diversification of ADC payloads by integrating novel cytotoxic agents and immune-modulatory compounds, thereby expanding therapeutic options and addressing heterogeneous resistance mechanisms. Citation Format: D. Rampa, N. Ogata, N. Sridhar, F. Takeo, C. Wannaphut, J. Maynard, K. Tsuchikama, G. Sledge, N. Ueno, J. Lee. Overcoming ADC Resistance: Payload Diversification as a Strategy for Sequential Therapy [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PD3-11.

Ewing/PNET (peripheral neuroepithelioma) tumors are rare aggressive bone sarcomas occurring in young people. Rare-disease clinical trials can require global collaborations and many years. In vivo models that as accurately as possible reflect the clinical disease are helpful in selecting therapeutics with the most promise of positive clinical impact. Human Ewing/PNET sarcoma cell lines developed over the past 45 years are described. Several of these have undergone genetic analysis and have been confirmed to be those of Ewing/PNET sarcoma. The A673 Ewing sarcoma line has proven to be particularly useful in understanding the biology of this disease in the mouse. The chromosomal translocation producing the EWS/FLI1 fusion transcript characterizes clinical Ewing sarcoma. Cell lines that express this genetic profile are confirmed to be those of Ewing sarcoma. The A673 Ewing sarcoma line grows in culture and as a xenograft in immunodeficient mice. The A673 model has been used to study Ewing sarcoma angiogenesis and response to antiangiogenic agents. Many Ewing sarcoma clinical specimens express the cell surface protein endosialin. Several Ewing sarcoma cell lines, including the A673 line, also express cell surface endosialin when grown as subcutaneous tumor nodules and as disseminated disease; thus the A673 is a useful model for the study of endosialin biology and endosialin-directed therapies. With the advent of tools that allow characterization of clinical disease to facilitate optimal treatment, it becomes imperative, especially for rare tumors, to develop preclinical models reflecting disease subsets. Ewing PNET sarcomas are a rare disease where models are available.

Focal Adhesion Kinase-Related Proline-Rich Tyrosine Kinase 2 and Focal Adhesion Kinase Are Co-Overexpressed in Early-Stage and Invasive ErbB-2-Positive Breast Cancer and Cooperate for Breast Cancer Cell Tumorigenesis and Invasiveness