Our results from quantitative RT-PCR, Western blotting, immunohistochemistry, and the tissue microarray of medullary thyroid cancer (MTC) cell lines and patient specimens confirm that VGSC subtype Na_V1.7 is uniquely expressed in aggressive MTC and not expressed in normal thyroid cells and tissues. We establish the druggability of Na_V1.7 in MTC by identifying a novel inhibitor (SV188) and investigate its mode of binding and ability to inhibit I_Na current in Na_V1.7. The whole-cell patch-clamp studies of the SV188 in the Na_V1.7 channels expressed in HEK-293 cells show that SV188 inhibited the I_Na current in Na_V1.7 with an IC₅₀ value of 3.6 µM by a voltage- and use-dependent blockade mechanism, and the maximum inhibitory effect is observed when the channel is open. SV188 inhibited the viability of MTC cell lines, MZ-CRC-1 and TT, with IC₅₀ values of 8.47 μM and 9.32 μM, respectively, and significantly inhibited the invasion of MZ-CRC-1 cells by 35% and 52% at 3 μM and 6 μM, respectively. In contrast, SV188 had no effect on the invasion of TT cells derived from primary tumor, which have lower basal expression of Na_V1.7. In addition, SV188 at 3 μM significantly inhibited the migration of MZ-CRC-1 and TT cells by 27% and 57%, respectively.

Hypoxia is a common feature of the tumor microenvironment, including that of triple-negative breast cancer (TNBC), an aggressive breast cancer subtype with a high five-year mortality rate. Using [¹⁸F]-fluoromisonidazole (FMISO) positron emission tomography (PET) imaging, we aimed to monitor changes in response to immunotherapy (IMT) with chemotherapy in TNBC. TNBC-tumor-bearing mice received paclitaxel (PTX) ± immune checkpoint inhibitors anti-programmed death 1 and anti-cytotoxic T-lymphocyte 4. FMISO-PET imaging was performed on treatment days 0, 6, and 12. Max and mean standard uptake values (SUV_max and SUV_mean, respectively), histological analyses, and flow cytometry results were compared. FMISO-PET imaging revealed differences in tumor biology between treatment groups prior to tumor volume changes. 4T1 responders showed SUV_mean 1.6-fold lower (p = 0.02) and 1.8-fold lower (p = 0.02) than non-responders on days 6 and 12, respectively. E0771 responders showed SUV_mean 3.6-fold lower (p = 0.001) and 2.7-fold lower (p = 0.03) than non-responders on days 6 and 12, respectively. Immunohistochemical analyses revealed IMT plus PTX decreased hypoxia and proliferation and increased vascularity compared to control. Combination IMT/PTX recovered the loss of CD4+ T-cells observed with single-agent therapies. PET imaging can provide timely, longitudinal data on the TNBC tumor microenvironment, specifically intratumoral hypoxia, predicting therapeutic response to IMT plus chemotherapy.

Obesity is defined as a BMI greater than 25 kg/m2. Once thought to simply be a nutritional disorder, obesity has become a major health concern characterized by a state of constant low-grade inflammation caused by chronic adiposity. This state of inflammation is characterized by circulating inflammatory mediators, such as IL-6, leptin, and TNF-α, as well as varying levels of glucose-regulating hormones produced by obese adipose tissue. When left untreated, obesity can lead to a number of diseases including, but not limited to, cardiovascular disease, metabolic syndrome, neurodegeneration, type II diabetes mellitus, chronic kidney disease, and infertility. The distribution of adiposity differs in men and women, and these differences, along with the differences in sex hormones and sex hormone levels, can exacerbate or attenuate the course of disease pathology. Obesity can also be exacerbated by stress, which can worsen disease pathogenesis. In this review, we will explore how obesity affects inflammation and disease and how sex can affect the course of these diseases.

Background/Objectives: Human epidermal growth factor receptor 2 (HER2)-positive breast cancer is linked to poorer overall survival and a higher risk of brain metastases compared to HER2-negative breast cancer. Current preclinical studies lack robust HER2+ metastatic syngeneic mouse models for investigating targeted and immunomodulatory therapies. This study aims to develop effective HER2+ mouse models to investigate response dynamics to HER2-targeted therapy and immunotherapy. Methods: The human HER2 gene (WT or mutant p.A775_G776insYVMA, GFP-tagged at the C-terminus) was introduced into triple-negative breast cancer (TNBC) mouse mammary carcinoma cells with known metastatic potential (4T1 and EO771) via lentiviral transduction. HER2 expression and phosphorylation were analyzed using Western blotting and immunohistochemistry. Tumors were treated with HER2-targeted therapy (trastuzumab and tucatinib), immune checkpoint blockade (anti-PD-1 and anti-CTLA-4), and anti-HER2 antibody–drug conjugate (ADC) to evaluate treatment efficacy. Metastatic potential was assessed with brain fluorescence imaging. Statistical analysis included ANOVA and Kaplan–Meier tests. Results: Newly established lines demonstrated expression of HER2+, with HER2^YVMA lines showing higher phosphorylation than HER2^WT lines. Cells were tumorigenic, demonstrating in vivo tumor take rates at 100% for 4T1-HER2 and 15–30% for EO771-HER2. HER2 overexpression led to a 30% increase in spontaneous brain metastasis in the 4T1-HER2 models. Trastuzumab alone did not reduce primary tumor size but significantly reduced brain GFP signal by 17% ± 8% and 26% ± 7% in the 4T1-HER2^WT and 4T1-HER2^YVMA models, respectively. Combinational therapies with anti-HER2 therapy and immune checkpoint blockade effectively suppressed primary tumor growth and prolonged survival in EO771-HER2^YVMA model. T-Dxd, but not T-DM1, demonstrated partial treatment response in the EO771-HER2^WT model. Conclusions: HER2+ syngeneic tumor models were developed that spontaneously metastasize to the brain and demonstrate variable responses to immunotherapies and ADCs. These models are valuable for advancing molecular imaging modalities for HER2+ brain metastasis, studying blood–brain barrier penetration of HER2-targeted drugs, and exploring the combination of therapies, including immunotherapy.

Triple-negative breast cancer (TNBC) lacks targeted therapies due to an absence of biomarkers, making chemotherapy the primary treatment option for early-stage cancer. This study evaluates whether the order and sequence of combination chemotherapy—doxorubicin (DRB) and paclitaxel (PTX)—affects treatment efficacy in TNBC. In vitro and in vivo models (MDA-MB-231 human and 4T1 syngeneic mouse TNBC) were used to assess treatment efficacy across three groups: saline control, DRB→PTX, and PTX→DRB. [¹⁸F]fluorothymidine (FLT) Positron emission tomography (PET) imaging was performed at baseline, day 3, and day 6 to monitor changes in tumor proliferation, and flow cytometry on day 6 examined immune profile differences in endpoint cohorts. Statistical significance was evaluated using the ANOVA and Kolmogorov-Smirnov test. In vitro experiments showed PTX→DRB treatment significantly reduced S/G2/M cell cycles and cancer cell viability. The MDA-MB-231 tumor model showed that PTX→DRB treatment significantly decreased cell proliferation and tumor heterogeneity comparing day 6 to baseline. In 4T1 models, DRB→PTX suppressed tumor growth and enhanced B cell and macrophage recruitment in immunocompetent but not immunocompromised mice. In both models, [¹⁸F]-FLT-PET plays a crucial role in directing the sequencing of chemotherapy in TNBC. Our study highlights the immune system's critical role in enhancing chemotherapy's efficacy. It provides compelling evidence that imaging can guide the sequencing of therapies by tracking changes in cellular proliferation and the heterogeneity of tumor response. This approach underscores the potential to refine treatment strategies for improved therapeutic outcomes.

Background/Objectives: Histone deacetylase (HDAC) inhibitors have been shown to prime the response to immunotherapy (IMT) treatment by inducing immune activation and infiltration to target tumor cells. Many studies primarily focus on adaptive immune cells and their expression of pro-inflammatory markers, like somatostatin receptor 2 (SSTR2); however, macrophages are known to help mediate key tumor microenvironment changes. The goal of this study is to evaluate the effects of HDAC inhibitors and IMT on macrophages, their expression of SSTR2, and their impact on the treatment response in triple-negative breast cancer (TNBC). Methods: Cytotoxic effects of HDAC inhibitors on 4T1 mouse mammary carcinoma cells, including suberoylanilide hydroxamic acid (SAHA), were evaluated using flow cytometry. Bone marrow-derived macrophages (BMDMs) were stimulated to M1-like and M2-like phenotypes and treated with SAHA to explore the effects on SSTR2 expression in different macrophage phenotypes. 4T1-tumor-bearing BALB/c mice were used to evaluate the therapy response to four treatments: saline control, SAHA, anti-PD-1 + anti-CTLA-4 checkpoint blockade IMT, or a combination of SAHA + IMT. Additional cohorts of 4T1-tumor-bearing BALB/c mice and NOD SCID mice, which lack adaptive immune cells, were euthanized for early evaluation of tumor-associated macrophage (TAM) populations via flow cytometry and cytokine analysis. One-way independent ANOVAs and log-rank tests were used to compare group differences. Results: SAHA promotes SSTR2 expression on M1-like BMDMs in vitro. SAHA promotes M2-like TAMs in vivo and stimulates pro-inflammatory, anti-tumor cytokine production in combination with IMT. Conclusions: SAHA drives SSTR2 expression and anti-tumor innate immune responses with additive effects in combination with immunotherapy in preclinical TNBC.