Statins in lymphangioleiomyomatosis. Simvastatin and atorvastatin induce differential effects on tuberous sclerosis complex 2-null cell growth and signaling

Statins block mammalian target of rapamycin pathway: a possible novel therapeutic strategy for inflammatory, malignant and neurodegenerative diseases

Inflammation plays a critical role in several diseases such as cancer, gastric, heart and nervous system diseases. Data suggest that the activation of mammalian target of rapamycin (mTOR) pathway in epithelial cells leads to inflammation. Statins, the inhibitors of the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA), seem to be able to inhibit the mTOR. Statins are considered to have favorable effects on inflammatory diseases by reducing the complications caused by inflammation and by regulating the inflammatory process and cytokines secretion. This critical review collected data on this topic from clinical, in vivo and in vitro studies published between 1998 and June 2022 in English from databases including PubMed, Google Scholar, Scopus, and Cochrane libraries.

The potential of Atorvastatin for chronic lung diseases therapy

Atorvastatin (ATO) is of the statin class and is used as an orally administered lipid-lowering drug. ATO is a reversible synthetic competitive inhibitor of 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase thus leading to a reduction in cholesterol synthesis. It has recently been demonstrated that ATO has different pharmacological actions, which are unrelated to its lipid-lowering effects and has the ability to treat chronic airway diseases. This paper reviews the potential of ATO as an anti-inflammatory, antioxidant, and anti-proliferative agent after oral or inhaled administration. This paper discusses the advantages and disadvantages of using ATO under conditions associated with those found in the airways. This treatment could potentially be used to support the formulating of ATO as an inhaler for the treatment of chronic respiratory diseases.

A phase II clinical trial of the Safety Of Simvastatin (SOS) in patients with pulmonary lymphangioleiomyomatosis and with tuberous sclerosis complex

INRODUCTION

The mechanistic target of rapamycin inhibitors (mTORi) sirolimus and everolimus stabilize lung function in patients with pulmonary lymphangioleiomyomatosis (LAM) but do not induce remission. Pre-clinical studies suggest that simvastatin in combination with sirolimus induces LAM cell death. The objective of this study was to assess the safety of simvastatin with either sirolimus or everolimus in LAM patients.

METHODS

This was a phase II single arm trial evaluating the safety of escalating daily simvastatin (20-40 mg) in LAM patients already treated with sirolimus or everolimus. Adverse events and changes in lipid panel profile, pulmonary function tests, and VEGF-D were assessed.

RESULTS

Ten LAM patients on a stable dose of mTORi for >3 months were treated with 20 mg simvastatin for two months followed by 40 mg for two months. The most common adverse events were peripheral edema (30%), cough (30%), and diarrhea (30%). No patients withdrew or had a reduction in simvastatin dose because of adverse events. Two patients required sirolumus dose reduction for supratherapeutic trough levels following simvastatin initiation. Total cholesterol and low density lipoproteins declined over the study period (-46.0 mg/dL±20.8, p = 0.008; -41.9 mg/dL±22.0, p = 0.01, respectively). There was also a decline in FEV1 (-82.0 mL±86.4, p = 0.02) but no significant change in FVC, DLCO, or VEGF-D.

CONCLUSIONS

The combination of simvastatin with mTORi in LAM patients is safe and well-tolerated from an adverse events perspective. The addition of simvastatin, however, was associated with decline in FEV1 and the efficacy of this combination should be explored in larger trials.

WISARD: workbench for integrated superfast association studies for related datasets

BACKGROUND

A Mendelian transmission produces phenotypic and genetic relatedness between family members, giving family-based analytical methods an important role in genetic epidemiological studies-from heritability estimations to genetic association analyses. With the advance in genotyping technologies, whole-genome sequence data can be utilized for genetic epidemiological studies, and family-based samples may become more useful for detecting de novo mutations. However, genetic analyses employing family-based samples usually suffer from the complexity of the computational/statistical algorithms, and certain types of family designs, such as incorporating data from extended families, have rarely been used.

RESULTS

We present a Workbench for Integrated Superfast Association studies for Related Data (WISARD) programmed in C/C++. WISARD enables the fast and a comprehensive analysis of SNP-chip and next-generation sequencing data on extended families, with applications from designing genetic studies to summarizing analysis results. In addition, WISARD can automatically be run in a fully multithreaded manner, and the integration of R software for visualization makes it more accessible to non-experts.

CONCLUSIONS

Comparison with existing toolsets showed that WISARD is computationally suitable for integrated analysis of related subjects, and demonstrated that WISARD outperforms existing toolsets. WISARD has also been successfully utilized to analyze the large-scale massive sequencing dataset of chronic obstructive pulmonary disease data (COPD), and we identified multiple genes associated with COPD, which demonstrates its practical value.

Somatic overgrowth disorders of the PI3K/AKT/mTOR pathway & therapeutic strategies

The phosphatidylinositol-3-kinase (PI3K)/AKT/mTOR signaling pathway plays an essential role in regulation of normal cell growth, metabolism, and survival. Somatic activating mutations in the PI3K/AKT/mTOR pathway are among the most common mutations identified in cancer, and have been shown to cause a spectrum of overgrowth syndromes including PIK3CA-Related Overgrowth Spectrum, Proteus syndrome, and brain overgrowth conditions. Clinical findings in these disorders may be isolated or multiple, including sporadic or mosaic overgrowth (adipose, skeletal, muscle, brain, vascular, or lymphatic), and skin abnormalities (including epidermal nevi, hyper-, and hypopigmented lesions), and have the potential risk of tumorigenesis. Key negative regulators of the PI3K-AKT signaling pathway include PTEN and TSC1/TSC2 and germline loss-of function mutations of these genes are established to cause PTEN Hamartoma Tumor Syndrome and Tuberous Sclerosis Complex. Mosaic forms of these conditions lead to increased activation of PI3K and mTOR at affected sites and there is phenotypic overlap between these conditions. All are associated with significant morbidity with limited options for treatment other than symptomatic therapies and surgeries. As dysregulation of the PI3K/AKT/mTOR pathway has been implicated in cancer, several small molecule inhibitors targeting different components of the PI3K/AKT/mTOR signaling pathway are under clinical investigation. The development of these therapies brings closer the prospect of targeting treatment for somatic PI3K/AKT/mTOR-related overgrowth syndromes. This review describes the clinical findings, gene function and pathogenesis of these mosaic overgrowth syndromes, and presents existing and future treatment strategies to reduce or prevent associated complications of these disorders. © 2016 Wiley Periodicals, Inc.

Could simvastatin be considered as a potential therapy for chronic lung diseases? A debate on the pros and cons

INTRODUCTION

Simvastatin (SV) is a drug from the statin class, currently used orally as an anti-cholesterolemic drug. It inhibits the 3-hydroxy-3-methyl-glutaryl-Coenzyme A (HMG-CoA) reductase to reduce cholesterol synthesis. Recently, it has been found that SV also has several other protective pharmacological actions unrelated to its anti-cholesterol effects that might be beneficial in the treatment of chronic airway diseases.

AREAS COVERED

This review summarizes the evidence relating to SV as a potential anti-inflammatory, anti-oxidant and muco-inhibitory agent, administered both orally and via pulmonary inhalation, and discusses its pro and cons. Evidence could potentially be used to support the delivery of SV as inhaled formulation for the treatment of chronic respiratory diseases.

EXPERT OPINION

The use of SV as anti-inflammatory, anti-oxidant and muco-inhibitory agent for drug delivery to the lung is promising. Inhaled SV formulations could allow the delivery profile to be customized and optimized to take advantage of the rapid onset of action, low systemic side effect and improved physico-chemical stability. This treatment could potentially to be used clinically for the localized treatment of lung diseases where inflammation and oxidative stress production is present.

Lymphangioleiomyomatosis: Current understanding and potential treatments

Lymphangioleiomyomatosis (LAM) is a rare neoplastic disease affecting predominantly young women. Clinical symptoms of this progressive disease include dyspnoea, cough, recurrent pneumothorax, hemoptysis and chylothorax. LAM is generally aggressive in nature and ultimately results in respiratory failure. Important hallmark features of this metastatic disease include the formation of lesions of abnormal smooth muscle cells, cystic destruction of the lung tissue and lymphangiogenesis affecting the lungs, abdomen and lymphatics. Research over the last 10-15 years has significantly enhanced our understanding of the molecular and cellular processes associated with LAM. These processes include mutational inactivation of the tuberous sclerosis complex genes, TSC1 and TSC2, activation of the mammalian target of rapamycin (mTOR) pathway, enhanced cell proliferation and migration, lymphangiogenesis, metastatic spread through the blood and lymphatic circulations, sex steroid sensitivity and dysregulated autophagy. Despite this increased knowledge there is currently no cure for LAM and treatment options remain limited. Whilst the mTOR inhibitor rapamycin has shown some benefit in patients with LAM, with stabilisation of lung function and improved quality of life, cessation of treatment results in recurrence of the disease progression. This highlights the urgent need to identify novel targets and new treatment regimens. The focus of this review is to summarise our current understanding of the cellular and molecular processes associated with LAM and highlight emerging treatments.

[Pulmonary lymphangioleiomyomatosis: From pathogenesis to management]

INTRODUCTION

Pulmonary lymphangioleiomyomatosis (LAM) is a rare disease affecting mainly young women.

BACKGROUND

The respiratory manifestations are characterized by a progressive cystic destruction of the lung parenchyma. Extrapulmonary involvement includes benign renal tumours called angiomyolipomas and abdominal lymphatic masses called lymphangioleiomyomas. At the pathological level, the cellular proliferation found in LAM is in part due to the presence of mutations in the tumour suppressor genes TSC1 and TSC2 (Tuberous Sclerosis Complex). These mutations lead to the activation of the mTOR pathway, which is currently the main therapeutic target. mTOR inhibitors such as sirolimus or everolimus have shown a beneficial effect on the decline in pulmonary function and a reduction of angiomyolipoma size, but are necessary in only some patients.

PERSPECTIVES

LAM cells have migratory properties mediated by the formation of new lymphatic vessels. They are also able to secrete metalloproteases, which enhance their invasiveness. Moreover, the expression of estrogen and progesterone receptors by LAM cells suggests a possible role for sex hormones in the pathogenesis of the disease.

CONCLUSION

A better understanding of mTOR-independent mechanisms would allow the development of novel therapeutic approaches.

The changing face of a rare disease: lymphangioleiomyomatosis

Lymphangioleiomyomatosis is a rare disease characterised by cystic destruction of the lung, lymphatic abnormalities and abdominal tumours. It affects almost exclusively females and can occur sporadically or in patients with tuberous sclerosis complex. In the past decade remarkable progress has been made in understanding of the pathogenesis of this disease leading to a new therapeutic approach. This review summarises recent advances regarding pathogenic mechanisms and clinical manifestations, and highlights the current and the most promising future therapeutic strategies.

Lymphangioleiomyomatosis: New Treatment Perspectives

Lymphangioleiomyomatosis (LAM) is a rare multisystem disease, occurs in women, usually premenopausal, caused by the proliferation of neoplastic smooth muscle-derived cells. Mutations in the tuberous sclerosis complex genes, lead to the activation of mammalian target of rapamycin kinase (mTOR), results in proliferation of LAM cells, its increasing motility, and survival. Polycystic lung destruction, extensive involvement of lymphatic channels, chylothorax, chyloperitoneum, and renal angiomyolipomas can develop in LAM patients. The new, promising treatment strategies have been recently introduced due to discovery of the genetic and molecular mechanisms of LAM. Comprehension of the disease pathogenesis has resulted in the implementation of other therapeutic agents such as mTOR inhibitors, VEGF-D inhibitors, statins, interferon, chloroquine analogs, cyclin-dependent kinase inhibitors, matrix metalloproteinase inhibitors, aromatase inhibitors, and their combinations. The mTOR inhibitors appear to be the most important, and the efficacy of sirolimus in LAM treatment has been proved. The article discussed the new control studies with mTOR inhibitors, doxycycline, simvastatin, and combination of them in LAM patients.

YAP enters the mTOR pathway to promote tuberous sclerosis complex

Mutations in tuberous sclerosis complex 1 (TSC1) or TSC2 predispose to angiomyolipomas and lymphangioleiomyomatosis in a mTOR-dependent manner. In these mesenchymal lesions, mTOR suppresses macroautophagy-mediated lysosomal degradation of YAP, which is a transcriptional coactivator of Hippo pathway and is required for the tumorigenesis of TSC. Therapeutic applications for TSC and other diseases with dysregulated mTOR activity can be envisaged.

Clinical features, epidemiology, and therapy of lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a multisystem disease of women, characterized by proliferation of abnormal smooth muscle-like LAM cells, leading to the formation of lung cysts, fluid-filled cystic structures in the axial lymphatics (eg, lymphangioleiomyomas), and renal angiomyolipomas. LAM is caused by mutations of the TSC1 or TSC2 genes, which encode, respectively, hamartin and tuberin, two proteins with a major role in control of the mammalian target of rapamycin (mTOR) signaling pathway. LAM occurs sporadically or in association with tuberous sclerosis complex, an autosomal-dominant syndrome characterized by widespread hamartomatous lesions. LAM may present with progressive dyspnea, recurrent pneumothorax, or chylothorax. Pulmonary function tests show reduced flow rates (forced expiratory volume in the first second) and diffusion capacity. Exercise testing may reveal gas exchange abnormalities, ventilatory limitation, and hypoxemia. The severity and progression of disease may be assessed by lung histology scores, quantification of computed tomography, pulmonary function testing, 6-minute walk tests, cardiopulmonary exercise testing, and measurement of serum vascular endothelial growth factor D levels. Sirolimus and everolimus, two mTOR inhibitors, are effective in stabilizing lung function and reducing the size of chylous effusions, lymphangioleiomyo-mas, and angiomyolipomas. However, inhibition of mTOR complex 1 increases autophagy, possibly enhancing LAM cell survival. Inhibition of autophagy with hydroxychloroquine, in combination with sirolimus, has been proposed as a possible treatment for LAM. Deficiency of tuberin results in increased RhoA GTPase activity and cell survival, an effect that is mediated through mTOR complex 2 signaling. Because sirolimus and everolimus only affect the activity of mTOR complex 1, therapies targeting RhoA GTPases with simvastatin, which inhibits Rho GTPases and promotes apoptosis, are being investigated. As in the case of cancer, LAM may be best treated with multiple drugs targeting signaling pathways considered important in the pathogenesis of disease.

Retrospective review of combined sirolimus and simvastatin therapy in lymphangioleiomyomatosis

BACKGROUND

Combined simvastatin and sirolimus therapy reduces tuberous sclerosis complex 2-null lesions and alveolar destruction in a mouse model of lymphangioleiomyomatosis (LAM), suggesting that therapy with both drugs may benefit patients with LAM.

METHODS

To determine whether simvastatin changed the prevalence of adverse events or altered the therapeutic effects of sirolimus, we recorded adverse events and changes in lung function in patients with LAM treated with simvastatin plus sirolimus (n = 14), sirolimus alone (n = 44), or simvastatin alone (n = 20).

RESULTS

Sirolimus-related adverse events in the simvastatin plus sirolimus and sirolimus-only groups were 64% and 66% for stomatitis, 50% and 52% for diarrhea, 50% and 45% for peripheral edema, 36% and 61% for acne, 36% and 30% for hypertension, 29% and 27% for proteinuria, 29% and 27% for leukopenia, and 21% and 27% for hypercholesterolemia. The frequency of simvastatin-related adverse events in the simvastatin-only and simvastatin plus sirolimus groups were 60% and 50% for arthralgias and 35% and 36% for myopathy. Before simvastatin plus sirolimus therapy, FEV1 and diffusing capacity of the lung for carbon monoxide (Dlco) yearly rates of change were, respectively, -1.4 ± 0.2 and -1.8 ± 0.2% predicted. After simvastatin plus sirolimus therapy, these rates changed to +1.2 ± 0.5 (P = .635) and +0.3 ± 0.4% predicted (P = .412), respectively. In 44 patients treated with sirolimus alone, FEV1 and Dlco rates of change were -1.7 ± 0.1 and -2.2 ± 0.1% predicted before treatment and +1.7 ± 0.3 and +0.7 ± 0.3% predicted after treatment (P < .001).

CONCLUSIONS

Therapy with sirolimus and simvastatin does not increase the prevalence of drug adverse events or alter the therapeutic effects of sirolimus.

The next breakthrough in LAM clinical trials may be their design: challenges in design and execution of future LAM clinical trials

The past decade has resulted in stunning progress in the pathogenesis and therapy of lymphangioleiomyomatosis (LAM), culminating in the pivotal 'MILES' trial, the first-ever randomized, placebo-controlled trial in LAM, demonstrating the efficacy of sirolimus in 2011. Here, we review clinical progress since 2011, focusing on new therapeutic and observational trials. These trials include the second randomized, placebo-controlled trial, a 2-year study of doxycycline effectiveness in LAM. Other clinical studies have addressed lower-dose sirolimus and treatment of pulmonary hypertension. An improved understanding of LAM pathogenesis is essential to future therapeutic breakthroughs. Critical questions that remain to be addressed include the role of estrogen and lymphangiogenesis in LAM pathogenesis and therapy, mechanisms of cystic lung destruction, the role of autophagy and pro-survival pathways in LAM cell survival. Ultimately, achieving future 'breakthroughs' in LAM will require continued rigorous basic and preclinical investigation, innovative clinical trial design and robust biomarkers.

New insights into the pathophysiology of the tuberous sclerosis complex: Crosstalk of mTOR- and hippo-YAP pathways in cell growth

Tuberous Sclerosis Complex (TSC) is a genetic disease causing uncontrolled growth of hamartomas involving different organ systems. In the last decade, dysregulation of the mTORC1 pathway was shown to be a main driver of tumor growth in TSC. Recently, a new crosstalk was detected between the mTORC1 and the Hippo-YAP pathway, another major cell signaling cascade controlling cell growth and organ size. Elucidating this connection is an important step in understanding the complexity of TSC, enabling new pharmacological targets and therapeutical options.

Management of lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM), a multisystem disease affecting almost exclusively women, is characterized by cystic lung destruction and presents with dyspnea, recurrent pneumothoraxes, chylous effusions, lymphangioleiomyomas, and angiomyolipomas. It is caused by the proliferation of a cancer-like LAM cell that possesses a mutation in either the tuberous sclerosis complex (TSC)1 or TSC2 genes. This article reviews current therapies and new potential treatments that are currently undergoing investigation. The major development in the treatment of LAM is the discovery of two mammalian target of rapamycin (mTOR) inhibitors, sirolimus and everolimus, as effective drugs. However, inhibition of mTOR increases autophagy, which may lead to enhanced LAM cell survival. Use of autophagy inhibitors, for example, hydroxychloroquine, in combination with sirolimus is now the subject of an ongoing drug trial (SAIL trial). Another consequence of mTOR inhibition by sirolimus is an increase in Rho activity, resulting in reduced programmed cell death. From these data, the concept evolved that a combination of sirolimus with disruption of Rho activity with statins (e.g. simvastatin) may increase TSC-null cell death and reduce LAM cell survival. A combined trial of sirolimus with simvastatin is under investigation (SOS trial). Since LAM occurs primarily in women and TSC-null cell survival and tumor growth is promoted by estrogens, the inhibition of aromatase to block estrogen synthesis is currently undergoing study (TRAIL trial). Other targets, for example, estrogen receptors, mitogen-activated protein kinase inhibitors, vascular endothelial growth factor-D signaling pathway, and Src kinase, are also being studied in experimental model systems. As in the case of cancer, combination therapy may become the treatment of choice for LAM.

Therapeutic Strategies for Treatment of Pulmonary Lymphangioleiomyomatosis (LAM)

INTRODUCTION

Pulmonary lymphangioleiomyomatosis (LAM) is a rare progressive lung disease affecting almost exclusively women. Neoplastic growth of atypical smooth muscle-like cells in the lung induces destruction of lung parenchyma leading to the formation of lung cysts, rupture of which results in spontaneous pneumothorax. LAM occurs sporadically or in association with inherited hamartoma syndrome tuberous sclerosis complex (TSC). Progression of LAM often results in loss of pulmonary function and death. Increasing understanding of neoplastic LAM cell growth is driving the development of therapeutic approaches targeting the disease progression.

AREAS COVERED

This review provides background to understand the rationale for current treatments used in patients with LAM, to critically appraise the evidence for these treatments, and to discuss future treatment approaches. The literature review includes publications from PubMed and clinicaltrials.gov/.

EXPERT OPINION

Targeting mTOR activation with rapamycin analogs sirolimus and everolimus are awaiting approval by the FDA for treatment of LAM. A number of other treatment options have been investigated and are currently tested in clinical trials to target LAM cell survival and metastasis. Key remaining and poorly understood areas for development and validation of therapeutic targeting in LAM are destruction of lungs, pathological lymphangiogenesis, and hormonal regulation. Future will reveal whether they could be targeted therapeutically.

Novel prospects of statins as therapeutic agents in cancer

Statins are well known competitive inhibitors of hydroxymethylglutaryl-CoA reductase enzyme (HMG-CoA reductase), thus traditionally used as cholesterol-lowering agents. In recent years, more and more effects of statins have been revealed. Nowadays alterations of lipid metabolism have been increasingly recognized as a hallmark of cancer cells. Consequently, much attention has been directed toward the potential of statins as therapeutic agents in the oncological field. Accumulated in vitro and in vivo clinical evidence point out the role of statins in a variety of human malignancies, in regulating tumor cell growth and anti-tumor immune response. Herein, we summarize and discuss, in light of the most recent observations, the anti-tumor effects of statins, underpinning the detailed mode of action and looking for their true significance in cancer prevention and treatment, to determine if and in which case statin repositioning could be really justified for neoplastic diseases.