Int. J. Transl. Med., Volume 3, Issue 3 (September 2023) – 9 articles

FLT3 mutations are frequently identified in acute myeloid leukemia (AML). In particular, FLT3-ITD is known to be an indicator of a poor prognosis. FLT3 inhibitors have improved the treatment outcomes of AML patients with mutated FLT3. However, several drug-resistance mechanisms have been reported, and new clinical strategies to overcome drug resistance are needed. Heat shock protein (HSP) 90 is a molecular chaperone that mediates the correct folding and functionality of its client proteins, including FLT3. In the present study, we investigated the effects of an HSP90 inhibitor on FLT3 inhibitor-resistant AML cells. Using MOLM-13 (an AML cell line harboring FLT3-ITD), we established FLT3-selective inhibitor (FI-700)-resistant cell lines with an FLT3 N676K mutation. An HSP90 inhibitor (17-AAG) inhibited the growth of the cell lines, and combination treatment with FI-700 and 17-AAG showed synergistic inhibition. The underlying mechanism is thought to be as follows: HSP90 inhibits the association between HSP90 and FLT3, and thus reduces the phosphorylation of FLT3 and its downstream signaling proteins, which induces the consequent degradation of FLT3. In summary, we demonstrated that the HSP90 inhibitor could inhibit the cell growth of FLT3 inhibitor-resistant AML cells. Our results suggest that HSP90 is a promising molecular target in relapsed/refractory AML. Full article

Type 1 Diabetes (T1D) is a chronic metabolic disorder for which current treatments are unable to prevent the onset of complications. Previously, we used an adeno-associated viral vector (AAV8) to deliver furin-cleavable human insulin (INS-FUR) to the livers of diabetic non-obese diabetic (NOD) mice to reverse T1D. The use of the traditional AAV8-INS-FUR vector could not bring about normoglycemia. However, this vector, coupled with a transposon system in the AAV8/piggyBac-INS-FUR vector, was able to do so. This study aimed to investigate the transcriptomic profiles of the livers of diabetic, AAV8-INS-FUR-transduced, and AAV8/piggyBac-INS-FUR-transduced NOD mice and compare these to the normal liver to identify genetic differences resulting from delivery of the AAV8/piggyBac-INS-FUR vector which produced normoglycemia. Differential gene expression was determined by RNA-Seq analysis and differentially expressed genes from each treatment were mapped onto cellular pathways to determine the treatments’ cell signaling and downstream effects. We observed distinct differences between the piggyBac-transduced and diabetic models, particularly in terms of metabolic function and the upregulation of key pancreatic markers in the liver of piggyBac-transduced animals. The success of the AAV8/piggyBac-INS-FUR vector in achieving normoglycemia through stable transduction was evident. However, further engineering is necessary to achieve complete pancreatic transdifferentiation of liver cells. Full article

Normal contractile function of the myocardium is essential for optimal cardiovascular health. Evaluating drug effects on cardiomyocyte function at the cellular level is difficult for long-term studies. Present culture systems rely on isolated, cardiomyocyte preparations or cardiomyocytes derived from pluripotent stem cells (PSCs), all of which have limitations. Isolated, endogenous cardiomyocytes do not remain contractile in culture long term. While PSC-derived cardiomyocytes show contractile activity for longer periods of time, their phenotype is more embryonic than adult. Here we report that dexamethasone (DEX) treatment of adult mouse atrial tissue can extend its functionality in culture. Normally, cardiac explants cease their capacity as a contractile tissue within the first month, as the tissue flattens and spreads out on the culture substrate, while the cells dedifferentiate and lose their myocardial phenotype. However, with DEX treatment, cardiac explants maintain their contractile function, 3D morphology, and myocyte phenotype for up to 6 months. Moreover, DEX also preserved the contractile phenotype of isolated rat cardiomyocytes. These data with DEX suggest that simple modifications in culture conditions can greatly improve the long-term utility of in vitro model systems for screening drugs and agents that could be employed to alleviate human cardiac disease. Full article

Preferentially expressed antigen in melanoma (PRAME) is a cancer testis antigen (CTA) that is selectively expressed in certain somatic tissues, predominantly in the testis, and is overexpressed in various cancers. PRAME family proteins are leucine-rich repeat proteins that are localized in the nucleus and cytoplasm, with multifaceted roles in immunity, during gametogenesis and in the overall reproduction process. It is a widely studied CTA and has been associated with the prognosis and therapeutic outcomes in patients with epithelial and non-epithelial tumors. PRAME has also been studied extensively as a therapeutic target. Moreover, it has been found to play a role in most of the well-known cancer hallmarks. Interestingly, the role of PRAME in tumorigenesis is paradoxical. Over the last decade, PRAME has garnered substantial interest as a target for immunotherapy. There are multiple clinical trials and pre-clinical studies targeting PRAME alone or in combination with other tumor antigens. This review article is an attempt to update our knowledge and understanding of the context-dependent oncogenic functions of PRAME in various carcinomas, and the current immunotherapeutic strategies, challenges, and perspectives on developing newer strategies to target PRAME for a better outcome. Full article

Endoscopic spine surgery (ESS) began more than 20 years ago as percutaneous endoscopic discectomy and has evolved to the present day. This technique offers many advantages, including a short hospital stay, minimal trauma and blood loss, the option of local or epidural anesthesia with sedation, a low rate of nosocomial infections, early recovery, and a quick return to work and daily activities. The success rate of this technique ranges from 83% to 90% in operated patients. This article aims to provide an overview of indications, versatility of the technique, advantages, contraindications and limitations, and also a reflection on the possible contraindications and limitations of the technique. Full article

Overexpression of human epidermal growth factor receptor 2 (HER2) in breast cancer is an important target of monoclonal antibody (mAb) therapy such as trastuzumab. Due to the development of trastuzumab–deruxtecan, an antibody-drug conjugate, the targetable HER2-positive breast cancer patients have been expanded. To evaluate the developing modalities using anti-HER2 mAbs, reliable preclinical mouse models are required. Therefore, sensitive mAbs against mouse HER2 (mHER2) should be established. This study developed anti-mHER2 mAbs using the Cell-Based Immunization and Screening (CBIS) method. The established anti-mHER2 mAbs, H₂Mab-300 (rat IgG_2b, kappa) and H₂Mab-304 (rat IgG₁, kappa), reacted with mHER2-overexpressed Chinese hamster ovary-K1 (CHO/mHER2) and endogenously mHER2-expressed cell line, NMuMG (a mouse mammary gland epithelial cell) via flow cytometry. Furthermore, these mAbs never recognized mHER2-knockout NMuMG cells. The kinetic analysis using flow cytometry indicated that the dissociation constant (K_D) values of H₂Mab-300 and H₂Mab-304 for CHO/mHER2 were 1.2 × 10⁻⁹ M and 1.7 × 10⁻⁹ M, respectively. The K_D values of H₂Mab-300 and H₂Mab-304 for NMuMG were 4.9 × 10⁻¹⁰ M and 9.0 × 10⁻¹⁰ M, respectively. These results indicated that H₂Mab-300 and H₂Mab-304 could apply to the detection of mHER2 using flow cytometry and may be useful to obtain the proof of concept in preclinical studies. Full article

In this study, the effects of foods containing lipopolysaccharide (LPS) from Pantoea agglomerans (LPSp) on immunity were preliminarily investigated using a double-blind, placebo-controlled, randomized, parallel-group comparative study design. Thirty healthy subjects aged ≥ 20 years (four males and twenty-six females; mean age 49 ± 9.2 years) were randomly assigned to the LPS-containing food group (488 μg/day; LPS) or placebo group. Each food was consumed for 8 weeks, and a subjective survey of cold symptoms (Wisconsin Upper Respiratory Symptom Questionnaire) and allergic symptoms of the eyes and nose were conducted. Phagocytic capacity and lymphocyte counts were measured as indicators of immune function. There were no significant between-group differences with respect to any of the investigated items. On sub-group analysis of eye–nose allergy symptom score, confined only to subjects who reported eye–nose allergic symptoms in previous years, the LPS group showed a trend toward milder symptoms compared to the placebo group. In addition, when the symptom scores were compared only for subjects who developed eye–nose allergies during the study period, the LPS group showed significantly lower overall scores and eye symptom scores compared to the placebo group. These results suggest that the consumption of LPS-containing foods may alleviate or prevent eye–nose allergies. There were no statistically predominant changes in hematology and blood biochemistry tests, indicating that continued consumption of LPS-containing foods is safe. (UMIN000046154). Full article

Androgen deprivation therapy (ADT) is the basis for the control of prostate cancer. High levels of prostate-specific antigen (PSA) and high Gleason grade correlate, define the aggressiveness of the cancer in order to establish its treatment and prognosis. This work evaluated the response of 910 patients diagnosed with prostate cancer, separated into three groups according to their response to treatment by ADT: (1) sensitive (TSPC); (2) palliative and did not accept treatment, and (3) group with recurrence or treatment resistance (TRPC). All patients with prostate cancer treated with ADT, and regardless of whether or not they had undergone surgery or taken to radiotherapy, presented with anemia. The hematological response due to the leukocyte/lymphocyte index (L/L) is increased at the end of treatment, possibly due to inflammatory processes generated by cancer, and baseline overweight and obesity. Patients with biochemical relapse exhibit a higher platelet count, suggesting that these cells could participate in the recurrence process and in metastasis (78%) in these patients. The coagulation index (INR) could be an indicator of the platelet response to be considered during the treatment and monitoring of patients. Full article

Immune-related hepatitis (irH) is a fairly frequent complication of immune checkpoint inhibitors (ICIs). Its management is generally based on withholding ICIs and on the rapid initiation of corticosteroids, which is successful in 63 to 96% of cases. Mycofenolate mofetil (MMF) is accepted as a second-line immunosuppressant in the case of the failure of corticosteroids. In rare cases, though, irH is also resistant to MMF and may lead to liver failure. There are no standard third-line treatments and current guidelines are based on a limited number of case reports. We present a case of a metastatic melanoma patient with an immune-related hepatitis refractory to corticosteroids and MMF, that was successfully reversed with tacrolimus. Unfortunately, this was complicated with a serious infection and progressive disease, which illustrates the complexity of treatment of steroid-refractory immunotherapy-related adverse events. Furthermore, we provided a literature review regarding the management of steroid-refractory hepatitis and proposed a strategy to circumvent the current uncertainties in the management of steroid-refractory irH. Full article