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Introduction: We analyzed randomized clinical trials (RCTs) evaluating the efficacy of combined therapy with low-level light therapy (LLLT) and topical minoxidil for treatment of androgenetic alopecia (AGA). Methods: A literature search within PubMed identified RCTs evaluating hair regrowth following LLLT and minoxidil. Selection criteria were 600–1,100 nm wavelengths, treatment time ≥16 weeks, and objective evaluation for hair regrowth. Results: Five RCTs compared LLLT with minoxidil (2% or 5%) to 5% minoxidil treatment or LLLT treatment. One study showed combination therapy of LLLT, and 5% minoxidil improved hair density more than monotherapy. Another found combination LLLT with 2% minoxidil induced hair regrowth equivalent to 5% minoxidil. Similarly, another study described LLLT with 5% minoxidil versus minoxidil monotherapy to increase the number of hairs with no statistical difference between groups. One trial found that combination group increased hair regrowth in the first 2 months. The last study found a statistically significant increase in hair density with combined therapy compared to monotherapy. Conclusion: The studies describe either superiority or equivalence of combination therapy to minoxidil monotherapy for AGA. Early outcomes appear to support the superiority of combination therapy, but this advantage wanes at the end of the study periods.

GHRH is a hypothalamic peptide shown to stimulate the proliferation of malignant cells in humans. We have previously shown that the use of GHRH antagonist MIA-602 successfully suppressed the growth of many human cancer cell lines, spanning more than 20 types of cancers. In this study, we demonstrate the presence of GHRH-R in the NB4, NB4-RAA, and K-562 model cell lines. Furthermore, we demonstrate the inhibited proliferation of all three cell lines in vitro after incubation with MIA-602. The treatment of xenografts of human APL cell lines with MIA-602 led to a significant reduction in tumor growth. Additionally, combination therapy with both doxorubicin (DOX) and MIA-602 showed a marked synergistic effect in reducing the proliferation of the K-562 AML cell line. These findings suggest that MIA-602 could be utilized to address resistance to all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) therapies, as well as in augmenting anthracycline-based regimens.

Introduction: Acute Myeloid Leukemia (AML) is a malignant neoplastic disease arising from myeloid cell lines. AML is characterized by the proliferation of immature, nonfunctional cells in the bone marrow. Acute Promyelocytic Leukemia (APL) is a subtype of AML characterized by proliferation of immature promyelocytes. Growth Hormone Releasing Hormone (GHRH) is a hypothalamic peptide that stimulates the release of Growth Hormone from the anterior pituitary. This study aimed to investigate the role of MIA-602, a growth hormone-releasing hormone receptor (GHRH-R) antagonist as front line-combination therapy in the K-562 in-vitro model of AML as well as its potential for treating ATRA/ATO resistant APL. Design: Western blot analysis was used to detect the GHRH-R in both K-562 and NB4 cell lines. K562 cells were maintained as a cell suspension in the RPMI medium, with 10% heat-inactivated fetal bovine serum and gentamicin. Doxorubicin treatment concentrations were 0.005, 0.01, and 0.05 μg/μl. Combination therapy concentrations were 0.005, 0.01, and 0.05 μg/μl of doxorubicin and 5 μmol/L of MIA-602. Proliferation was observed and recorded at 24h and 48h. Wild type NB4 cells and NB4 cells resistant to both ATRA and ATO (NB4-RAA) were cultured in suspension. Cell lysates were prepared after incubation with MIA-602. Cell viability was measured at 24, 48, and 72h. Flow cytometry was also performed to assess expression of CD-56. Results: Incubation of cells with doxorubicin showed a decrease in proliferation in a dose-dependent manner. Co-incubation of K562 cells with MIA-602 and doxorubicin showed a significantly greater reduction in proliferation (p5.8-fold; p,0.05) in NB4-RAA cells as compared to the parent cell line. Discussion: Co-administration of doxorubicin and the GHRH-R antagonist MIA-602 was shown to have a synergistic effect in reducing proliferation of the K-562 AML cell line. Use of MIA-602 in front-line combination therapy with anthracycline-based regimens may help prevent the acquisition of resistance in AML. CD-56 plays an essential role in the regulation of cell survival and stress resistance. Aberrant expression of CD-56 is also associated with reduced complete remission rates, higher relapse rates, and poor overall survival. The equal effectiveness of MIA-602 in cells with increased expression of CD-56 may provide an important therapeutic option in the setting of resistance. Citation Format: Ravinder S. Chale, Mario Rodriguez, Stephanie M. Almeida, Shelly Sclatter, Anastasia Singaready, Andrew V. Schally, Joaquin J. Jimenez. Synergistic effects of MIA-602 and its potential for use in ATRA/ATO Resistant APL [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 385.

Acute Promyelocytic Leukemia (APL) is characterized by proliferation of immature promyelocytes. Combination therapy using retinoic acid (RA) and arsenic trioxide (ATO) is considered standard treatment in the clinical environment. Resistance to both RA and ATO is associated with an increased risk of mortality. In addition, relapse occurs in approximately 10-20% of patients undergoing treatment for APL. Growth Hormone Releasing Hormone (GHRH) is a hypothalamic peptide that stimulates the release of Growth Hormone from the anterior pituitary. Our previous studies have demonstrated that human AML cell lines (K-562, THP-1, and KG-1a) display the GHRH receptor (GHRH-R). Incubation with GHRH-R antagonist MIA-602, inhibited proliferation and induced apoptosis. The purpose of this study is to examine the effects of GHRH-R antagonist MIA-602, on the NB4 Human Promyelocytic Leukemia cell line and its ATRA and ATO resistant sub-clone. NB4 cells expressed both GHRH-R and SV1 variants via western blot analysis. Wild type NB4 cells, as well as NB4 cells resistant to both ATRA and ATO (NB4-RAA), were cultured in suspension in RPMI and 10% fetal calf serum. NB4-RAA were established in Dr. Jimenez's lab from the wild type NB4 parent cell line. NB4 and NB4-RAA were plated in triplicate on multi-wells at 50,000 cells/mL. Cell lysates were prepared after incubation with 0.05-5 µmol/L of MIA-602. Cell viability was measured at 24 and 48h. Flow cytometry was also performed on the naïve NB4 parent cell line in addition to NB4-RAA to assess expression of CD-56 the cell surface marker. Upregulation of CD-56, also known as Neural cell adhesion molecule 1 (NCAM-1), has been shown to confer drug resistance in AML and is an important prognostic marker in APL. The viability of both cell lines decreased to similar levels at 24 h and 48 h when exposed to concentrations of MIA-602 higher than 0.05 μmol/L (p < 0.05). A significant decrease in cell viability was seen above 0.5 μmol/L after 48h. No viable cells were found in either cell line after 48h when exposed to 5 μmol/L of MIA-602. No difference in cell viability was found between naïve NB4 and resistant NB4-RAA when exposed to the same concentrations of MIA-602. MIA-602 induced significant changes in the expression level of many death-related genes including CASP9 (>1.5-fold; P5.8-fold; p,0.05) in NB4-RAA cells as compared to the parent cell line. These results indicate that resistance to ATRA and ATO in APL cells does not confer subsequent resistance to MIA-602. As a result, MIA-602 targets a pathway that is distinct from that of ATRA & ATO. More importantly, upregulation of pro-apoptotic genes by MIA-602 indicates an alternative pathway elicited by the GHRH-R antagonist in the setting of resistant APL cells. Our results indicate that the resistance to frontline APL therapy can be effectively overcome by using MIA-602. Citation Format: Ravinder S. Chale, Stephanie M. Almeida, Ivan Jozic, Andrew V. Schally, Joaquin J. Jimenez. A novel approach to the treatment of ATRA/ATO resistant acute promyelocytic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5317.

A complex interaction of signalling events, including the Wnt pathway, regulates sprouting of blood vessels from pre-existing vasculature during angiogenesis. Here we show that two distinct mutations in the (uro)chordate-specific gumby (also called Fam105b) gene cause an embryonic angiogenic phenotype in gumby mice. Gumby interacts with disheveled 2 (DVL2), is expressed in canonical Wnt-responsive endothelial cells and encodes an ovarian tumour domain class of deubiquitinase that specifically cleaves linear ubiquitin linkages. A crystal structure of gumby in complex with linear diubiquitin reveals how the identified mutations adversely affect substrate binding and catalytic function in line with the severity of their angiogenic phenotypes. Gumby interacts with HOIP (also called RNF31), a key component of the linear ubiquitin assembly complex, and decreases linear ubiquitination and activation of NF-κB-dependent transcription. This work provides support for the biological importance of linear (de)ubiquitination in angiogenesis, craniofacial and neural development and in modulating Wnt signalling. This study identifies a deubiquitinase (DUB) that specifically recognises and cleaves linear ubiquitin chains, implicating linear (de)ubiquitination in Wnt signalling and angiogenesis; mutations in gumby cause defects in angiogenesis in mice, and structural and biochemical analysis shows that gumby encodes a linear-ubiquitin-specific DUB. The gumby mutation in mice is associated with lethal angiogenic defects in the embryo. Here Sabine Cordes and colleagues show that the gumby gene encodes a deubiquitinase that specifically recognizes and cleaves linear ubiquitin chains and they implicate linear (de)ubiquitination in Wnt signalling and angiogenesis. In humans, gumby-containing deletions on chromosome 5p15.2 are associated with mental retardation and craniofacial anomalies observed in cri du chat syndrome (CdCS) patients. Although not the only gene deleted, gumby might contribute to some CdCS symptoms via its effects on linear deubiquitination. This work identifies gumby and the pathways regulating the deubiquitination–ubiquitination balance as of possible relevance to antiangiogenic therapies.