Efficacy of fluvastatin and aspirin for prevention of hormonally insensitive breast cancer

Impact of Lipid-Lowering Therapy on Cancer Risk: A Narrative Review

PURPOSE

There are inconsistent reports of an association between low cholesterol, use of lipid-lowering agents, and carcinogenesis. The purpose of this paper was to examine the relationship between cancer, lipids, statin use, and use of other lipid-lowering therapies.

METHODS

This comprehensive literature review incorporated article searches in electronic databases (Embase, PubMed, OVID) and reference lists of relevant articles, with the authors' expertise in lipidology. This review considered seminal and novel research looking at the relationship between cholesterol, lipid-lowering therapies, and cancer.

FINDINGS

Statin use has been reported to reduce the risk for incident cancer or progression of cancer; however, it is unknown whether this reduced risk of carcinogenesis is due to the pleotropic properties of statins or the effects of low cholesterol. The effect of ezetimibe on carcinogenesis has been regarded as neutral, despite earlier concerns of increased cancer risk with its use. Proprotein convertase subtilisin/kexin (PCSK)-9 monoclonal antibodies have been shown to have a neutral effect on carcinogenesis. Despite anti-cancer effects of fibrates in vitro, studies in humans have yielded inconsistent outcomes leaning toward protection against the development and progression of cancer.

IMPLICATIONS

Statins, fibrates, PCSK9 monoclonal antibodies, and ezetimibe have a neutral effect on cancer risk, and the first three may provide some protection. PSCK9 monoclonal antibodies have the potential to enhance the response to checkpoint inhibitor therapy for cancer. Further research is needed to determine which drugs can be issued in adjuvant therapy to improve outcomes in patients undergoing cancer treatment.

Neutrophils for Revascularization Require Activation of CCR6 and CCL20 by TNFα

BACKGROUND

Activation of immune-inflammatory pathways involving TNFα (tumor necrosis factor alpha) signaling is critical for revascularization and peripheral muscle tissue repair after ischemic injury. However, mechanisms of TNFα-driven inflammatory cascades directing recruitment of proangiogenic immune cells to sites of ischemia are unknown.

METHODS

Muscle tissue revascularization after permanent femoral artery ligation was monitored in mutant mice by laser Doppler imaging and light sheet fluorescence microscopy. TNFα-mediated signaling and the role of the CCL20 (C-C motif chemokine ligand 20)-CCR6 (C-C chemokine receptor 6) axis for formation of new vessels was studied in vitro and in vivo using bone marrow transplantation, flow cytometry, as well as biochemical and molecular biological techniques.

RESULTS

TNFα-mediated activation of TNFR (tumor necrosis factor receptor) 1 but not TNFR2 was found to be required for postischemic muscle tissue revascularization. Bone marrow-derived CCR6+ neutrophil granulocytes were identified as a previously undescribed TNFα-induced population of proangiogenic neutrophils, characterized by increased expression of VEGFA (vascular endothelial growth factor A). Mechanistically, postischemic activation of TNFR1 induced expression of the CCL20 in vascular cells and promoted translocation of the CCL20 receptor CCR6 to the cell surface of neutrophils, essentially conditioning VEGFA-expressing proangiogenic neutrophils for CCL20-dependent recruitment to sites of ischemia. Moreover, impaired revascularization of ischemic peripheral muscle tissue in diabetic mice was associated with reduced numbers of proangiogenic neutrophils and diminished CCL20 expression. Administration of recombinant CCL20 enhanced recruitment of proangiogenic neutrophils and improved revascularization of diabetic ischemic skeletal muscles, which was sustained by sequential treatment with fluvastatin.

CONCLUSIONS

We demonstrate that site-specific activation of the CCL20-CCR6 axis via TNFα recruits proangiogenic VEGFA-expressing neutrophils to sites of ischemic injury for initiation of muscle tissue revascularization. The findings provide an attractive option for tissue revascularization, particularly under diabetic conditions.

The molecular heterogeneity of the precancerous breast affects drug efficacy

In the therapeutic domain, targeted therapies have been shown to be generally more effective when given to patients with tumors that harbor the targeted aberration. This principle has not been tested in cancer prevention despite evidence that molecular heterogeneity accompanies the multi-step progression to invasive disease. We hypothesized that efficacy of agents targeting the precancerous state varies based on timing of the treatment relative to the underlying molecular changes. MCF10A cell line-based model of the multi-step progression to TNBC was used. Global proteomic patterns were obtained and growth-inhibitory effects of selected agents were correlated with the underlying molecular stage of progression. These analyses revealed that most protein alterations were acquired in the normal-to-atypia (preneoplasia) transition, with only handful aberrations acquired hereafter. The efficacy of small molecule inhibitors of the AKT/MEK pathway was associated with the underlying pathway levels. Similarly, fluvastatin was more effective in inhibiting cell proliferation earlier in the progression model. However, the nonspecific inhibitors, aspirin and metformin, were equally ineffective in inhibiting proliferation across the progression model. Our data provides proof-of-principle that in the prevention domain, treatment with agents developed to target specific pathways, will need to consider the molecular heterogeneity of the precancerous breast in order to achieve maximum efficacy.

The Link Between Statins and Breast Cancer in Mouse Models: A Systematic Review

Statins, a class of cholesterol-lowering drugs, have consistently demonstrated pleiotropic effects in both preclinical and clinical studies. Outside of inhibiting the production of cholesterol in cells, statins have shown antineoplastic properties most commonly in breast cancer. Clinical and epidemiological studies, however, are less definitive than preclinical studies regarding statins as potential adjuvant oncologic therapy. Our objective is to summarize mouse model studies that investigate the link between statins and breast cancer using a cancer care continuum framework to provide a clinically relevant picture of the potential use of statins in breast cancer. A systematic review of the PubMed database was performed to identify studies published between January 2007 and July 2022 that investigated the effects of statins on breast cancer prevention, treatment, and survivorship in mouse models. Overall, 58 studies were identified using our search strategy. Based on our inclusion and exclusion criteria, 26 mouse model studies were eligible to be included in our systematic review. In breast cancer mouse models, statins alone and in combination with anti-cancer therapies demonstrate proven antineoplastic effects across the cancer care continuum. The antineoplastic benefit of statins as single agents in mouse model studies helps inform their synergistic benefit that future clinical studies can test. Parameters such as statin timing, dose, and breast cancer subtype are key stepping stones in defining how statins could be used in the treatment of breast cancer.

Gene signature associated with resistance to fluvastatin chemoprevention for breast cancer

Background

Although targeting of the cholesterol pathway by statins prevents breast cancer development in mouse models, efficacy is not absolute. Therefore, the goal of this study is to investigate if the upregulation in the cholesterol biosynthesis pathway genes associates with response to statin chemoprevention and may potentially be used as response biomarkers.

Methods

Expression of cholesterol biosynthesis pathway genes was initially derived from the RNA sequencing of MCF10A cell line- based breast cancer progression model system and subsequently validated by quantitative PCR assay. Response to fluvastatin was assessed in vitro using the MCF10A cell line model system, including a statin resistant cell line that was generated (MCF10.AT1-R), and measured using colony forming assays. In vivo efficacy of statin for chemoprevention was assessed in the SV40C3 TAg mouse model. Mammary tumors were identified by histologic analysis of the mammary glands. Mammary glands without histologic evidence of high-grade lesions (in situ and/or invasive carcinoma) were considered responsive to statin treatment.

Results

We found more than 70% of a published multi-gene fluvastatin resistance signature to be significantly upregulated during breast cancer progression and inversely correlated with statin inhibition of cellular growth and proliferation. This inherent statin resistance gene signature was also largely shared with the signature of acquired resistance to fluvastatin in MCF10.AT1-R cell line model of acquired statin resistance. These inherent resistance genes and genes exclusive to acquired statin resistance map to steroid-, and terpenoid backbone- biosynthesis pathway. We found upregulation of ~ 80% of cholesterol biosynthesis pathway genes in the tumor bearing mammary glands of SV40 C3TAg transgenic mouse model of TNBC, suggesting the involvement of cholesterol biosynthesis pathway in resistance to statin chemoprevention in vivo. A panel of 13-genes from the pathway significantly associated with response to statin treatment, as did the expression level of HMGCR alone in a mouse model of breast cancer suggesting their utility to predict the efficacy of statin chemoprevention.

Conclusions

High basal level, or restorative upregulation, in the cholesterol biosynthesis pathway genes appear to be strongly associated with resistance to statin chemoprevention for breast cancer and may serve as a biomarker to tailor statin treatment to individuals who are most likely to benefit.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09353-2.

Overcoming chemoresistance in glioblastoma by fluvastatin via prenylation-dependent inhibition of Ras signaling

The resistance of glioblastoma to chemotherapy remains a significant clinical problem. Targeting alternative pathways such as protein prenylation is known to be effective against many cancers. Fluvastatin is a potent competitive inhibitor of 3-hydroxy-3-methylglutaryl- CoA (HMG-CoA) reductase, thereby inhibits prenylation. We demonstrate that fluvastatin alone effectively inhibits proliferation and induces apoptosis in multiple human glioblastoma cell lines. The combination index analysis shows that fluvastatin acts synergistically with common chemotherapy drugs for glioblastoma: temozolomide and irinotecan. We further show that fluvastatin acts on glioblastoma through inhibiting prenylation-dependent Ras activation. The combination of fluvastatin and low dose temozolomide resulted in remarkable inhibition of glioblastoma tumor in mice throughout the whole treatment duration without causing toxicity. Such combinatorial effects provide the basis for utilizing these FDA-approved drugs as a potential clinical approach in overcoming resistance and improving glioblastoma treatment.