Chemotherapy is the main treatment for triple-negative breast cancer (TNBC), a subtype of breast cancer that is aggressive with a poor prognosis. While chemotherapeutics are potent, these agents lack specificity and are equally toxic to cancer and nonmalignant cells and tissues. Targeted therapies for TNBC treatment could lead to more safe and efficacious drugs. We previously engineered a breast cancer cell targeting peptide 18-4 that specifically binds cell surface receptor keratin 1 (K1) on breast cancer cells. A conjugate of peptide 18-4 and doxorubicin (Dox) containing an acid-sensitive hydrazone linker showed specific toxicity toward TNBC cells. Here, we report the in vivo evaluation of the K1 targeting peptide-Dox conjugate (PDC) in a TNBC cell-derived xenograft mouse model. Mice treated with the conjugate show significantly improved antitumor efficacy and reduced off-target toxicity compared to mice treated with Dox or saline. After six weekly treatments, on day 35, the mice treated with PDC (2.5 mg Dox equivalent/kg) showed significant reduction (1.5 times) in tumor volume compared to mice treated with Dox (2.5 mg/kg). The mice treated with the conjugate showed significantly higher (1.4 times) levels of Dox in tumors and lower (1.3–2.2 times) levels of Dox in other organs compared to mice treated with Dox. Blood collected at 15 min showed 3.6 times higher concentration of the drug (PDC and Dox) in mice injected with PDC compared to the drug (Dox) in mice injected with Dox. The study shows that the K1 targeting PDC is a promising novel modality for treatment of TNBC, with a favorable safety profile, and warrants further investigation of K1 targeting conjugates as TNBC therapeutics.

Interferon-gamma (IFN-γ) is shown to stimulate melanoma development and progression. However, the underlying mechanism has not been completely defined. Our study aimed to determine the role of neuronal nitric oxide synthase (nNOS)-mediated signaling in IFN-γ-stimulated melanoma progression and the anti-melanoma effects of novel nNOS inhibitors. Our study shows that IFN-γ markedly induced the expression levels of nNOS in melanoma cells associated with increased intracellular nitric oxide (NO) levels. Co-treatment with novel nNOS inhibitors effectively alleviated IFN-γ-activated STAT1/3. Further, reverse phase protein array (RPPA) analysis demonstrated that IFN-γ induced the expression of HIF1α, c-Myc, and programmed death-ligand 1 (PD-L1), in contrast to IFN-α. Blocking the nNOS-mediated signaling pathway using nNOS-selective inhibitors was shown to effectively diminish IFN-γ-induced PD-L1 expression in melanoma cells. Using a human melanoma xenograft mouse model, the in vivo studies revealed that IFN-γ increased tumor growth compared to control, which was inhibited by the co-administration of nNOS inhibitor MAC-3-190. Another nNOS inhibitor, HH044, was shown to effectively inhibit in vivo tumor growth and was associated with reduced PD-L1 expression levels in melanoma xenografts. Our study demonstrates the important role of nNOS-mediated NO signaling in IFN-γ-stimulated melanoma progression. Targeting nNOS using highly selective small molecular inhibitors is a unique and effective strategy to improve melanoma treatment.

Oral chemotherapy (OC) has been increasingly used in pediatric patients diagnosed with cancer, which is primarily managed in the outpatient setting. Different from adults, pediatric patients face unique challenges in administering these hazardous medications at home. Because of the complexity of pediatric pharmaceutical care and the hazardous nature of chemotherapy agents, comprehensive patient education is imperative to mitigate the potential safety risks associated with OC administration at home. Pharmacists play a vital role in patient education and medication consultations. However, the lack of practice guidelines and limited resources supporting OC counseling are noted. Additional barriers include insufficient knowledge and training on OC, which can be improved by continuing education. In a regional children’s hospital, a comprehensive OC education checklist was developed for pediatric patients and their caregivers to standardize consultations led by pharmacists. An infographic OC handout was also formulated to improve patient knowledge and awareness. Moreover, innovative approaches such as using telepharmacy, smartphone applications, and artificial intelligence have been increasingly integrated into patient care, which can help optimize OC consultations for children and adolescents. Further studies are warranted to enhance oral chemotherapy education specifically tailored for pediatric patients in outpatient settings.

To identify the clinical and pharmacological risk factors associated with tacrolimus pharmacodynamics for acute graft‐versus‐host disease (aGVHD) in pediatric patients receiving allogeneic hematopoietic stem cell transplantation (HSCT) from a matched related donor. A retrospective cohort single center chart review study was conducted with pediatric patients who received tacrolimus prophylaxis after allogeneic HSCT between January 1, 2017, and December 31, 2019. Potential risk factors were tested separately between aGVHD and non‐aGVHD cohorts and were further analyzed in a logistic regression model with backward elimination and a partial least squares discriminant analysis. Thirty‐three patient cases were included in our study and 52% (17/33) developed aGVHD while on tacrolimus prophylaxis. When tested independently, donor age and sibling versus parent donor/recipient relation were shown to be statistically significant between aGVHD and non‐aGVHD patients (p < 0.005). Pharmacological factors associated with tacrolimus treatment failed to demonstrate a significant impact on patient’s risk of aGVHD. Using a best fit logistic regression model that tested all the variables together, donor age was the only significant variable predicting patient’s risk of aGVHD (p < 0.01). Donor relationship and donor age were unable to be evaluated separately and are therefore confounding variables. Among pediatric patients receiving allogeneic HSCT, aGVHD risk is significantly decreased by either sibling donor and/or younger donors. Although no conclusions were drawn on the effect of tacrolimus therapy (p = 0.08), results warrant additional research with a larger sample size to evaluate the accuracy of monitoring tacrolimus serum trough levels.

Despite the benefits of red blood cell (RBC) transfusion therapy, it can render patients vulnerable to iron overload. The excess iron deposits in various body tissues cause severe complications and organ damage such as cardiotoxicity and mold infections. Clostridioides difficile infection (CDI) is the most common cause of nosocomial diarrhea among cancer patients and is associated with significant morbidity and mortality. Our study aims to determine the role of iron overload and the effects of iron chelators on CDI. Our results demonstrated that iron (Fe³⁺) stimulated the growth of C. difficile with increased colony formation units (CFU) in a dose-dependent manner. Exposure to excess iron also increased the gene expression levels of tcdA and tcdB. The production of C. difficile toxin A, necessary for the pathogenesis of C. difficile, was also elevated after iron treatment. In the presence of excess iron, C. difficile becomes less susceptible to metronidazole with significantly elevated minimum inhibitory concentration (MIC) but remains susceptible to vancomycin. Iron-stimulated colony formation and production of C. difficile toxins were effectively diminished by iron chelator deferoxamine co-treatment. Incorporating iron overload status as a potential factor in developing a risk prediction model of CDI and antibiotic treatment response may aid clinical practitioners in optimizing CDI management in oncology patients.

Background/Objectives: Cannabinoid Hyperemesis Syndrome (CHS), associated with long-term cannabinoid use, has been increasingly observed in emergency room visits as more states in the U.S. have legislatively permitted medical and recreational marijuana use. The acute management of CHS primarily focuses on antiemetic treatment and supportive care. However, both the condition itself and the antiemetic drugs, such as haloperidol, may cause QTc prolongation. Methods: We reported two adolescent cases admitted to the emergency department for acute antiemesis management of CHS who received haloperidol treatment. A literature review was performed through October 2024 for previously published cases of QTc prolongation and/or Torsades de Pointes (TdP) in adolescents and young adults. Results: A 15-year-old female presented with hypokalemia and hypomagnesemia upon admission. She complained of chest pain and tachycardia, and the electrocardiogram (EKG) showed prolonged QTc (528 msec). The haloperidol infusion was discontinued. She recovered well post-discharge without complaints. A 17-year-old female had a borderline prolonged QT interval (476 msec). Her nausea and vomiting improved with a three-dose course of intravenous fosaprepitant before discharge. Our literature search identified five severe cases with life-threatening episodes of QTc prolongation and/or TdP in adolescents and young adults. Conclusions: Patients with CHS are at higher risk of QTc prolongation due to cannabis use, electrolyte imbalance, and antiemetic medications. We recommend vigilant EKG monitoring, particularly before initiating and throughout haloperidol treatment. If the patient presents with an increased risk of QTc prolongation, consider using topical capsaicin, lorazepam, aprepitant/fosaprepitant, and olanzapine as alternatives.