The Role of High Dose Chemotherapy with Autologous Hematopoietic Cell Transplant in Relapsed/Refractory Ovarian Germ Cell Tumors: A Single Center Experience.

OBJECTIVE: We aimed to investigate response rates, survival analyses and factors affecting survival in patients with relapsed or refractory ovarian germ cell tumours who had previously received multiple lines of treatment, including high-dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT). METHODS: This study was designed as a cross-sectional, retrospective study. RESULTS: Twenty-one patients were included. After HDC + ASCT, complete response (CR) was observed in 11 patients (52.3%), partial response (PR) in 3 patients (14.3%), stable disease (SD) in 3 patients (14.3%) and progressive disease (PD) in 4 patients (19.1%). TRM was observed in 1 patient. Median follow-up was 51.7 months. Median PFS and OS after HDC + ASCT were calculated to be 6.0 months and 14.8 months, respectively. CONCLUSIONS: Salvage HDC + ASCT is an effective option in the treatment of relapsed/refractory ovarian germ cell tumours, offering the potential for prolonged survival and cure.

High-Dose Chemotherapy and Autologous Stem Cell Transplantation for Salvage Therapy of Relapsed/Refractory Germ Cell Tumors: A Single-Center Experience.

INTRODUCTION: The optimal management of relapsed/refractory germ cell tumors remains unsettled. In this study, we aimed to evaluate the efficacy of high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT) as salvage therapy in patients who progressed after at least one line of cisplatin-based chemotherapy. METHODS: We retrospectively reported the results of 133 patients who underwent HDCT and ASCT as salvage therapy from 2016 to 2021. Patients received 3 cycles of paclitaxel, ifosfomide and cisplatin (TIP) regimen as induction and 1 cycle of carboplatin 700 mg/m2 on days 1-3 plus etoposide 750 mg/m2 on days 1-3, followed by ASCT. Demographic and clinicopathological features of patients, the International Germ Cell Cancer Collaborative Group (IGCCCG) risk group at diagnosis, serum alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (HCG) levels before HDCT, treatment-related complications and survival outcomes were recorded. RESULTS: The median age of the patients was 31 (range 18-62). The median follow-up was 31.1 months (95% CI, 28.9-33.3 months). During the median follow-up period, 74 of the 133 patients were still alive, and 63 of these were in complete remission. The median progression-free survival (PFS) was 25.8 months (95% CI, 8.1-43.4 months). The 2-year PFS rate was 50.3% and the 2-year overall survival (OS) rate was 60.8%. Variables that remained statistically significant in multivariable analysis and were associated with poor prognosis were mediastinal primary tumor location, presence of brain metastases, and higher AFP and HCG levels at baseline. CONCLUSION: One course of HDCT and ASCT after induction with TIP is an effective and feasible treatment option for salvage treatment of relapsed/refractory germ cell tumors, with cure rates of up to 60%.

Evaluation of clinical and prognostic factors for primary gastric diffuse large B-cell lymphoma: Single-center experience.

Objective: Primary gastric lymphomas, which make up the vast majority of extranodal non-Hodgkin lymphoma, are rare and the most common subtype is primary gastric diffuse large B-cell lymphoma (PG-DLBCL). In our study, we investigated the clinical and prognostic factors of this lymphoma type as a single-center experience. Materials and Methods: Between January 2001 and February 2021, 91 patients aged ≥18 years, registered with the diagnosis of primary gastric DLBCL, diagnosed histopathologically, and whose evaluation parameters were reached, were retrospectively scanned. Results: The median age of 91 patients with a diagnosis of PG-DLBCL was 58 (20-81, minimum-maximum) years. Of the patients, 64.8% were men and 35.2% were women. While the number of patients with an International Prognostic Index (IPI) score of 0-2 (low-low-intermediate risk) was 54 (59.4%), the number of patients with an IPI score of 3 (high intermediate) was 19 (20.9%), and the number of patients with an IPI score of 4-5 (high risk) was 18 (19.8%). While 52.7% of the patients had a complete response, 20.9% had a partial response, 3.3% had stable disease, and 23.1% had progressive disease. The 10-year event-free survival (EFS) and overall survival (OS) rates for all patients, respectively, were 52.1% and 53.2%. We found factors affecting survival in univariate analysis; age groups (≤60/>60), ECOG groups (0-1/≥2), Lugano stage (I-II/III-IV), LDH level (normal/high), IPI risk groups (low/low-intermediate/high-intermediate/high) and radiotherapy (yes/no). In multivariate analysis, only; age groups (≤60/>60) and IPI risk groups (low/low-intermediate/high-intermediate/high) were found to be independent factors affecting survival. In addition, in our study, we determined that the division of the IPI intermediate risk group into low intermediate and high intermediate is one of the factors predicting prognosis. Conclusions: Few studies of PG-DLBCL have investigated the long-term survival rates of patients and primarily examined small patient groups because of the low incidence of the disease. In our study, we think that detailed evaluation of age and especially IPI risk groups play a role in predicting survival.

Efficacy of subsequent treatments in patients with hormone-positive advanced breast cancer who had disease progression under CDK 4/6 inhibitor therapy.

BACKGROUND: There is no standard treatment recommended at category 1 level in international guidelines for subsequent therapy after cyclin-dependent kinase 4/6 inhibitor (CDK4/6) based therapy. We aimed to evaluate which subsequent treatment oncologists prefer in patients with disease progression under CDKi. In addition, we aimed to show the effectiveness of systemic treatments after CDKi and whether there is a survival difference between hormonal treatments (monotherapy vs. mTOR-based). METHODS: A total of 609 patients from 53 centers were included in the study. Progression-free-survivals (PFS) of subsequent treatments (chemotherapy (CT, n:434) or endocrine therapy (ET, n:175)) after CDKi were calculated. Patients were evaluated in three groups as those who received CDKi in first-line (group A, n:202), second-line (group B, n: 153) and ≥ 3rd-line (group C, n: 254). PFS was compared according to the use of ET and CT. In addition, ET was compared as monotherapy versus everolimus-based combination therapy. RESULTS: The median duration of CDKi in the ET arms of Group A, B, and C was 17.0, 11.0, and 8.5 months in respectively; it was 9.0, 7.0, and 5.0 months in the CT arm. Median PFS after CDKi was 9.5 (5.0-14.0) months in the ET arm of group A, and 5.3 (3.9-6.8) months in the CT arm (p = 0.073). It was 6.7 (5.8-7.7) months in the ET arm of group B, and 5.7 (4.6-6.7) months in the CT arm (p = 0.311). It was 5.3 (2.5-8.0) months in the ET arm of group C and 4.0 (3.5-4.6) months in the CT arm (p = 0.434). Patients who received ET after CDKi were compared as those who received everolimus-based combination therapy versus those who received monotherapy ET: the median PFS in group A, B, and C was 11.0 vs. 5.9 (p = 0.047), 6.7 vs. 5.0 (p = 0.164), 6.7 vs. 3.9 (p = 0.763) months. CONCLUSION: Physicians preferred CT rather than ET in patients with early progression under CDKi. It has been shown that subsequent ET after CDKi can be as effective as CT. It was also observed that better PFS could be achieved with the subsequent everolimus-based treatments after first-line CDKi compared to monotherapy ET.

Sonographic measurement of the neck extensor muscle thickness in patients with fibromyalgia.

OBJECTIVE: The aim of this cross-sectional study was to compare cervical extensor muscle thickness measurements in patients with fibromyalgia (FM) with chronic neck pain and an asymptomatic control group, and to examine the relationship between cervical extensor muscle thickness and pain, quality of life, and disability. METHODS: The study included 41 patients with FM and 41 asymptomatic control subjects. The thickness of the cervical extensor muscles (multifidus, semispinalis capitis, semispinalis cervicis, splenius capitis and trapezius muscles) was evaluated with ultrasonography. The severity of FM was evaluated with the Fibromyalgia Impact Questionnaire (FIQ), neck disability with the Neck Disability Index (NDI) and pain severity with a Numeric Rating Scale (NRS). RESULTS: The mean sonographic thickness values of all the neck extensor muscles were significantly decreased in the FM group compared with the control group (p < 0.001). There were negative correlations between the FIQ and multifidus, splenius capitis and trapezius thickness values. NDI was significantly negatively correlated with multifidus and trapezius thickness. There was no significant correlation between neck extensor muscle thickness and age, duration of FM, and NRS scores. CONCLUSION: This study demonstrated a decrease in cervical extensor muscle thickness in patients with FM with chronic neck pain. Cervical extensor muscle morphologies should be considered by the clinician when planning treatment in patients with FM with neck pain.

Stress-Mediated Reprogramming of Prostate Cancer One-Carbon Cycle Drives Disease Progression.

One-carbon (1C) metabolism has a key role in metabolic programming with both mitochondrial (m1C) and cytoplasmic (c1C) components. Here we show that activating transcription factor 4 (ATF4) exclusively activates gene expression involved in m1C, but not the c1C cycle in prostate cancer cells. This includes activation of methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) expression, the central player in the m1C cycle. Consistent with the key role of m1C cycle in prostate cancer, MTHFD2 knockdown inhibited prostate cancer cell growth, prostatosphere formation, and growth of patient-derived xenograft organoids. In addition, therapeutic silencing of MTHFD2 by systemically administered nanoliposomal siRNA profoundly inhibited tumor growth in preclinical prostate cancer mouse models. Consistently, MTHFD2 expression is significantly increased in human prostate cancer, and a gene expression signature based on the m1C cycle has significant prognostic value. Furthermore, MTHFD2 expression is coordinately regulated by ATF4 and the oncoprotein c-MYC, which has been implicated in prostate cancer. These data suggest that the m1C cycle is essential for prostate cancer progression and may serve as a novel biomarker and therapeutic target. SIGNIFICANCE: These findings demonstrate that the mitochondrial, but not cytoplasmic, one-carbon cycle has a key role in prostate cancer cell growth and survival and may serve as a biomarker and/or therapeutic target.

STAMP2 Expression Mediated by Cytokines Attenuates Their Growth-Limiting Effects in Prostate Cancer Cells.

Inflammatory events and dysregulated cytokine expression are implicated in prostate cancer (PCa), but the underlying molecular mechanisms are poorly understood at present. We have previously identified six transmembrane protein of the prostate 2 (STAMP2, also known as STEAP4) as an androgen-regulated gene, as well as a key regulator of PCa growth and survival. STAMP2 is also regulated by, and participates in, inflammatory signaling in other tissues and pathologies. Here, we show that the proinflammatory cytokines interleukin 6 (IL-6) and Interleukin 1 beta (IL-1ß) significantly increase and strongly synergize in promoting STAMP2 expression in PCa cells. The two cytokines increase androgen-induced STAMP2 expression, but not expression of other known androgen target genes, suggesting a unique interplay of androgens and cytokines in regulating STAMP2 expression. Interestingly, STAMP2 knockdown significantly increased the ability of IL-6 and IL-1ß to inhibit PCa cell growth in vitro. These results suggest that STAMP2 may represent a unique node through which inflammatory events mediate their effects on PCa growth and survival.

The impact of transfusion burden and comorbidities on the prognosis of patients with myelodysplastic syndromes.

PURPOSE: Early comorbidity detection has been reported to be associated with treatment-related outcomes in several diseases. Two main goals of the present study were to investigate both the impact of comorbidities and transfusion frequencies on the survival and quality of life of patients with myelodysplastic syndromes (MDS). METHODS: One hundred and four MDS patients with a median International Prognostic Scoring System (IPSS) score of 0.5 (range: 0-3) were included in the study. Almost half of the patients had more than one comorbidity. RESULTS: Median short form health surveys (SF)-36 mental and physical scores were 42.1 (range: 20.6-66.1) and 38.7 (range: 18-59.7), respectively. Mean scores of the Eastern Cooperative Oncology Group (ECOG) performance scales at diagnosis and during recruitment were 1.0 (1.4 ± 1.0) and 2.0 (1.8 ± 1.1), respectively. The mean Charlson Comorbidity Index (CCI) score was 1.0 (1.4 ± 1.5). In the model that was constructed using variables with a p value < 0.100 in the univariate analysis, factors that predicted death were refractory anemia with excess blasts (RAEB) and ECOG scores at recruitment. When ECOG was removed from the model, RAEB and CCI at diagnosis moved to the forefront as mortality predictors. CONCLUSION: This study demonstrated that both CCI and ECOG performance status had an impact on survival in MDS patients who had low IPSS scores. ECOG stood out as a better and more practical predictor of survival than CCI, especially after considering its (ECOG) ease of use.

Regulation of the unfolded protein response through ATF4 and FAM129A in prostate cancer.

Cancer cells exploit many of the cellular adaptive responses to support their survival needs. One such critical pathway in eukaryotic cells is the unfolded protein response (UPR) that is important in normal physiology as well as disease states, including cancer. Since UPR can serve as a lever between survival and death, regulated control of its activity is critical for tumor formation and growth although the underlying mechanisms are poorly understood. Here we show that one of the main transcriptional effectors of UPR, activating transcription factor 4 (ATF4), is essential for prostate cancer (PCa) growth and survival. Using systemic unbiased gene expression and proteomic analyses, we identified a novel direct ATF4 target gene, family with sequence similarity 129 member A (FAM129A), which is critical in mediating ATF4 effects on prostate tumorigenesis. Interestingly, FAM129A regulated both PERK and eIF2α in a feedback loop that differentially channeled the UPR output. ATF4 and FAM129A protein expression is increased in patient PCa samples compared with benign prostate. Importantly, in vivo therapeutic silencing of ATF4-FAM129A axis profoundly inhibited tumor growth in a preclinical PCa model. These data support that one of the canonical UPR branches, through ATF4 and its target gene FAM129A, is required for PCa growth and thus may serve as a novel therapeutic target.

IRE1α-XBP1s pathway promotes prostate cancer by activating c-MYC signaling.

Activation of endoplasmic reticulum (ER) stress/the unfolded protein response (UPR) has been linked to cancer, but the molecular mechanisms are poorly understood and there is a paucity of reagents to translate this for cancer therapy. Here, we report that an IRE1α RNase-specific inhibitor, MKC8866, strongly inhibits prostate cancer (PCa) tumor growth as monotherapy in multiple preclinical models in mice and shows synergistic antitumor effects with current PCa drugs. Interestingly, global transcriptomic analysis reveal that IRE1α-XBP1s pathway activity is required for c-MYC signaling, one of the most highly activated oncogenic pathways in PCa. XBP1s is necessary for optimal c-MYC mRNA and protein expression, establishing, for the first time, a direct link between UPR and oncogene activation. In addition, an XBP1-specific gene expression signature is strongly associated with PCa prognosis. Our data establish IRE1α-XBP1s signaling as a central pathway in PCa and indicate that its targeting may offer novel treatment strategies.

Identification of WEE1 as a target to make AKT inhibition more effective in melanoma.

AKT3 is one of the major therapeutic targets in melanoma but clinically targeting AKT3 alone seems to be an ineffective therapeutic approach. To identify unique strategies to enhance the efficacy of targeting AKT3, a screen was undertaken where AKT3 was co-targeted with a panel of kinases important in melanoma development. The screen identified WEE1 as the most potent target that when inhibited along with AKT3 would enhance the efficacy of targeting AKT3 in melanoma. RNAi mediated inhibition of AKT3 and WEE1 synergistically inhibited the viability of melanoma cells leading to a 65-75% decrease in tumor development. This approach was effective by mechanistically modulating pathways associated with the transcription factors p53 and FOXM1. Simultaneously regulating the activity of these two transcriptionally driven pathways, cooperatively deregulated cell cycle control and DNA damage repair to synergistically kill melanoma cells. This study uniquely identifies a potential approach to improve the efficacy of targeting AKT3 in melanoma.

Modulating cancer cell survival by targeting intracellular cholesterol transport.

BACKGROUND: Demand for cholesterol is high in certain cancers making them potentially sensitive to therapeutic strategies targeting cellular cholesterol homoeostasis. A potential approach involves disruption of intracellular cholesterol transport, which occurs in Niemann-Pick disease as a result of acid sphingomyelinase (ASM) deficiency. Hence, a class of lysosomotropic compounds that were identified as functional ASM inhibitors (FIASMAs) might exhibit chemotherapeutic activity by disrupting cancer cell cholesterol homoeostasis. METHODS: Here, the chemotherapeutic utility of ASM inhibition was investigated. The effect of FIASMAs on intracellular cholesterol levels, cholesterol homoeostasis, cellular endocytosis and signalling cascades were investigated. The in vivo efficacy of ASM inhibition was demonstrated using melanoma xenografts and a nanoparticle formulation was developed to overcome dose-limiting CNS-associated side effects of certain FIASMAs. RESULTS: Functional ASM inhibitors inhibited intracellular cholesterol transport leading to disruption of autophagic flux, cellular endocytosis and receptor tyrosine kinase signalling. Consequently, major oncogenic signalling cascades on which cancer cells were reliant for survival were inhibited. Two tested ASM inhibitors, perphenazine and fluphenazine that are also clinically used as antipsychotics, were effective in inhibiting xenografted tumour growth. Nanoliposomal encapsulation of the perphenazine enhanced its chemotherapeutic efficacy while decreasing CNS-associated side effects. CONCLUSIONS: This study suggests that disruption of intracellular cholesterol transport by targeting ASM could be utilised as a potential chemotherapeutic approach for treating cancer.

Improving pharmacological targeting of AKT in melanoma.

Targeting AKT with pharmacological agents inhibiting this protein in the melanoma clinic is ineffective. This is a major contradiction considering the substantial preclinical data suggesting AKT as an effective target. Various approaches have been undertaken to unravel this contradiction and drug combinations sought that could resolve this concern. We have shown that genetic targeting AKT3 or WEE1 can be effective for inhibiting tumor growth in preclinical animal models. However, no one has examined whether combining pharmacological agents targeting each of these enzymes could be more effective than inhibiting each alone and enhance the efficacy of targeting AKT in melanoma. This report shows that combining the AKT inhibitors (AZD5363 or MK1775) with the WEE1 inhibitor, AZD5363, can synergistically kill cultured melanoma cells and decrease melanoma tumor growth by greater than 90%. Co-targeting AKT and WEE1 led to enhanced deregulation of the cell cycle and DNA damage repair pathways by modulating the transcription factors p53 and FOXM1, as well as the proteins whose expression is regulated by these two proteins. Thus, this study identifies a unique combination of pharmacological agents and the ratio needed for efficacy that could be used to potentially improve the therapeutic effectiveness of targeting AKT in the clinic.

Identifying the structure-activity relationship of leelamine necessary for inhibiting intracellular cholesterol transport.

Leelamine is an anticancer chemotherapeutic agent inhibiting intracellular cholesterol transport. Cell death mediated by leelamine occurs due to the lysosomotropic property of the compound, its accumulation in the lysosome, and inhibition of cholesterol transport leading to lack of availability for key processes required for functioning of cancer cells. The present study dissects the structure-activity-relationship of leelamine using synthesized derivatives of leelamine and abietic acid, a structurally similar compound, to identify the moiety responsible for anti-cancer activity. Similar to leelamine, all active derivatives had an amino group or a similar moiety that confers a lysosomotropic property to the compound enabling its accumulation in the lysosome. Active derivatives inhibited intracellular cholesterol transport and hindered xenografted melanoma tumor development without obvious systemic toxicity. In silico studies suggested that active derivatives accumulating in lysosomes bound to NPC1, a protein responsible for cholesterol export from the lysosome, to inhibit its activity that then caused accumulation, and lack of cholesterol availability for other key cellular activities. Thus, active derivatives of leelamine or abietic acid maintained lysosomotropic properties, bound to NPC1, and disrupted cellular cholesterol transport as well as availability to retard tumor development.

Effect of lysosomotropic molecules on cellular homeostasis.

Weak bases that readily penetrate through the lipid bilayer and accumulate inside the acidic organelles are known as lysosomotropic molecules. Many lysosomotropic compounds exhibit therapeutic activity and are commonly used as antidepressant, antipsychotic, antihistamine, or antimalarial agents. Interestingly, studies also have shown increased sensitivity of cancer cells to certain lysosomotropic agents and suggested their mechanism of action as a promising approach for selective destruction of cancer cells. However, their chemotherapeutic utility may be limited due to various side effects. Hence, understanding the homeostatic alterations mediated by lysosomotropic compounds has significant importance for revealing their true therapeutic potential as well as toxicity. In this review, after briefly introducing the concept of lysosomotropism and classifying the lysosomotropic compounds into two major groups according to their cytotoxicity on cancer cells, we focused on the subcellular alterations mediated by class-II lysosomotropic compounds. Briefly, their effect on intracellular cholesterol homeostasis, autophagy and lysosomal sphingolipid metabolism was discussed. Accordingly, class-II lysosomotropic molecules inhibit intracellular cholesterol transport, leading to the accumulation of cholesterol inside the late endosomal-lysosomal cell compartments. However, the accumulated lysosomal cholesterol is invisible to the cellular homeostatic circuits, hence class-II lysosomotropic molecules also upregulate cholesterol synthesis pathway as a downstream event. Considering the fact that Niemann-Pick disease, a lysosomal cholesterol storage disorder, also triggers similar pathologic abnormalities, this review combines the knowledge obtained from the Niemann-Pick studies and lysosomotropic compounds. Taken together, this review is aimed at allowing readers a better understanding of subcellular alterations mediated by lysosomotropic drugs, as well as their potential therapeutic and/or toxic activities.

The Role of Cholesterol in Cancer.

The roles played by cholesterol in cancer development and the potential of therapeutically targeting cholesterol homeostasis is a controversial area in the cancer community. Several epidemiologic studies report an association between cancer and serum cholesterol levels or statin use, while others suggest that there is not one. Furthermore, the Cancer Genome Atlas (TCGA) project using next-generation sequencing has profiled the mutational status and expression levels of all the genes in diverse cancers, including those involved in cholesterol metabolism, providing correlative support for a role of the cholesterol pathway in cancer development. Finally, preclinical studies tend to more consistently support the role of cholesterol in cancer, with several demonstrating that cholesterol homeostasis genes can modulate development. Because of space limitations, this review provides selected examples of the epidemiologic, TCGA, and preclinical data, focusing on alterations in cholesterol homeostasis and its consequent effect on patient survival. In melanoma, this focused analysis demonstrated that enhanced expression of cholesterol synthesis genes was associated with decreased patient survival. Collectively, the studies in melanoma and other cancer types suggested a potential role of disrupted cholesterol homeostasis in cancer development but additional studies are needed to link population-based epidemiological data, the TCGA database results, and preclinical mechanistic evidence to concretely resolve this controversy. Cancer Res; 76(8); 2063-70. ©2016 AACR.

Current State of Animal (Mouse) Modeling in Melanoma Research.

Despite the considerable progress in understanding the biology of human cancer and technological advancement in drug discovery, treatment failure remains an inevitable outcome for most cancer patients with advanced diseases, including melanoma. Despite FDA-approved BRAF-targeted therapies for advanced stage melanoma showed a great deal of promise, development of rapid resistance limits the success. Hence, the overall success rate of melanoma therapy still remains to be one of the worst compared to other malignancies. Advancement of next-generation sequencing technology allowed better identification of alterations that trigger melanoma development. As development of successful therapies strongly depends on clinically relevant preclinical models, together with the new findings, more advanced melanoma models have been generated. In this article, besides traditional mouse models of melanoma, we will discuss recent ones, such as patient-derived tumor xenografts, topically inducible BRAF mouse model and RCAS/TVA-based model, and their advantages as well as limitations. Although mouse models of melanoma are often criticized as poor predictors of whether an experimental drug would be an effective treatment, development of new and more relevant models could circumvent this problem in the near future.

A non-cytotoxic N-dehydroabietylamine derivative with potent antimalarial activity.

Malaria caused by the Plasmodium parasites continues to be an enormous global health problem owing to wide spread drug resistance of parasites to many of the available antimalarial drugs. Therefore, development of new classes of antimalarial agents is essential to effectively treat malaria. In this study, the efficacy of naturally occurring diterpenoids, dehydroabietylamine and abietic acid, and their synthetic derivatives was assessed for antimalarial activity. Dehydroabietylamine and its N-trifluoroacetyl, N-tribromoacetyl, N-benzoyl, and N-benzyl derivatives showed excellent activity against P. falciparum parasites with IC50 values of 0.36 to 2.6 µM. Interestingly, N-dehydroabietylbenzamide showed potent antimalarial activity (IC50 0.36), and negligible cytotoxicity (IC50 >100 µM) to mammalian cells; thus, this compound can be an important antimalarial drug. In contrast, abietic acid was only marginally effective, exhibiting an IC50 value of ~82 µM. Several carboxylic group-derivatives of abietic acid were moderately active with IC50 values of ~8.2 to ~13.3 µM. These results suggest that a detailed understanding of the structure-activity relationship of abietane diterpenoids might provide strategies to exploit this class of compounds for malaria treatment.

Nanolipolee-007, a novel nanoparticle-based drug containing leelamine for the treatment of melanoma.

Malignant melanoma is a difficult cancer to treat due to the rapid development of resistance to drugs targeting single proteins. One response to this observation is to identify single pharmacologic agents that, due to a unique mechanism of action, simultaneously target multiple key pathways involved in melanoma development. Leelamine has been identified as functioning in this manner but has poor bioavailability in animals and causes lethality when administered intravenously. Therefore, a nanoliposomal-based delivery system has been developed, called Nanolipolee-007, which stably loads 60% of the compound. The nanoparticle was as effective at killing melanoma cells as leelamine dissolved in DMSO and was more effective at killing cultured melanoma compared with normal cells. Mechanistically, Nanolipolee-007 inhibited PI3K/Akt, STAT3, and MAPK signaling mediated through inhibition of cholesterol transport. Nanolipolee-007 inhibited the growth of preexisting xenografted melanoma tumors by an average of 64% by decreasing cellular proliferation, reducing tumor vascularization, and increasing cellular apoptosis, with negligible toxicity. Thus, a unique clinically viable nanoparticle-based drug has been developed containing leelamine for the treatment of melanoma that acts by inhibiting the activity of major signaling pathways regulating the development of this disease.