ABL allosteric inhibitors synergize with statins to enhance apoptosis of metastatic lung cancer cells

Low-Dose Atorvastatin has Promoting Effect on Melanoma Tumor Growth and Angiogenesis in Mouse Model

Background

Preclinical evidence indicates that statins possess diverse antineoplastic effects in different types of tumors. However, clinical studies have yielded conflicting results regarding the potential of statins to either increase or decrease the risk of cancer. Our objective was to examine the relationship between the dose of a treatment and its impact on melanoma tumor growth and angiogenesis in an in vivo setting.

Materials and Methods

Melanoma cells were injected into C57BL6 mice in four groups. They received 0, 1, 5, and 10 mg/kg of atorvastatin daily. Three others received the mentioned doses one week before the inoculation of melanoma animals. At the end of the third week, the animals were euthanized in a humane manner, and both blood samples and tumor specimens were collected for subsequent analysis.

Results

The tumor size was 1.16 ± 0.25 cm3 in a group treated with therapeutic dose of atorvastatin and was significantly larger than that in the control group (0.42 ± 0.08 cm3). However, there were no significant differences between the two other doses and the control group (0.72 ± 0.22, 0.46 ± 0.08 cm3 in atorvastatin-treated groups with 5 and 10 mg/kg). The vascular density of the tumors was significantly increased in the lowest dose of the atorvastatin treatment group, similar to the results of tumor size (P < 0.05).

Conclusion

Atorvastatin, at low therapeutic concentrations, has been observed to stimulate tumor growth and exhibit pro-angiogenic effects. Therefore, it is advised to exercise caution and recommend clinically relevant doses of statins to patients with cancer.

Paradoxical effects of statins on endothelial and cancer cells: the impact of concentrations

In addition to their lipid-lowering functions, statins elicit additional pleiotropic effects on apoptosis, angiogenesis, inflammation, senescence, and oxidative stress. Many of these effects have been reported in cancerous and noncancerous cells like endothelial cells (ECs), endothelial progenitor cells (EPCs) and human umbilical vein cells (HUVCs). Not surprisingly, statins' effects appear to vary largely depending on the cell context, especially as pertains to modulation of cell cycle, senescence, and apoptotic processes. Perhaps the most critical reason for this discordance is the bias in selecting the applied doses in various cells. While lower (nanomolar) concentrations of statins impose anti-senescence, and antiapoptotic effects, higher concentrations (micromolar) appear to precipitate opposite effects. Indeed, most studies performed in cancer cells utilized high concentrations, where statin-induced cytotoxic and cytostatic effects were noted. Some studies report that even at low concentrations, statins induce senescence or cytostatic impacts but not cytotoxic effects. However, the literature appears to be relatively consistent that in cancer cells, statins, in both low or higher concentrations, induce apoptosis or cell cycle arrest, anti-proliferative effects, and cause senescence. However, statins' effects on ECs depend on the concentrations; at micromolar concentrations statins cause cell senescence and apoptosis, while at nonomolar concentrations statins act reversely.

Association between Statin Use and Survival in Cancer Patients with Brain Metastasis: Retrospective Analysis from the Chinese Population

Brain metastasis predicts a worse clinical outcome in cancer patients. Emerging observational evidence suggests that statin use has a protective role in overall cancer prevention. Whether statin use could also be a supplementary treatment for advanced-stage cancers remains under researched and controversial. Data for cancer patients with brain metastasis were selected from the linked electronic medical care records of the West China Hospital between October 2010 and July 2019. Fisher’s exact chi-square test was used to compare the differences between cohorts. Multivariate Cox analysis was conducted to adjust the potential confounders in evaluating the role of statin use in the overall survival (OS) of cancer patients with brain metastasis. There were 4510 brain metastatic patients included in this retrospective study. The overall statin use rate in our patients was 5.28% (219 cases/4510 cases). Compared with the non-statin use cohort, patients who received statin therapy showed a decreased Karnofsky performance score (KPS, p < 0.001) and lower high-density lipoprotein (HDL, p = 0.020) but higher body mass index (BMI, p = 0.002) and triglyceride (TG, p < 0.001) at admission. There was no association between statin use and the OS of the cancer patients with brain metastasis (Hazard ratio (HR) = 0.90, 95% confidence interval (CI): 0.73−1.07, p = 0.213) during the univariate analysis. However, after adjusting for baseline patient characteristics, metabolism indicators, and cancer-specific factors, statin use was shown to have a significant protective role, aiding the survival of the cancer patients with brain metastasis (adjustHR = 0.82, 95%CI: 0.69−0.99, p = 0.034). Our results highlight that statin use shows significant survival benefits in cancer patients with brain metastasis. However, future research is needed to validate our findings.

Allostery: Allosteric Cancer Drivers and Innovative Allosteric Drugs

Here, we discuss the principles of allosteric activating mutations, propagation downstream of the signals that they prompt, and allosteric drugs, with examples from the Ras signaling network. We focus on Abl kinase where mutations shift the landscape toward the active, imatinib binding-incompetent conformation, likely resulting in the high affinity ATP outcompeting drug binding. Recent pharmacological innovation extends to allosteric inhibitor (GNF-5)-linked PROTAC, targeting Bcr-Abl1 myristoylation site, and broadly, allosteric heterobifunctional degraders that destroy targets, rather than inhibiting them. Designed chemical linkers in bifunctional degraders can connect the allosteric ligand that binds the target protein and the E3 ubiquitin ligase warhead anchor. The physical properties and favored conformational state of the engineered linker can precisely coordinate the distance and orientation between the target and the recruited E3. Allosteric PROTACs, noncompetitive molecular glues, and bitopic ligands, with covalent links of allosteric ligands and orthosteric warheads, increase the effective local concentration of productively oriented and placed ligands. Through covalent chemical or peptide linkers, allosteric drugs can collaborate with competitive drugs, degrader anchors, or other molecules of choice, driving innovative drug discovery.

Effect of Statins on Lung Cancer Molecular Pathways: A Possible Therapeutic Role

Lung cancer is a common neoplasm, usually treated through chemotherapy, radiotherapy and/or surgery. Both clinical and experimental studies on cancer cells suggest that some drugs (e.g., statins) have the potential to improve the prognosis of cancer. In fact, statins blocking the enzyme "hydroxy-3-methylglutaryl-coenzyme A reductase" exert pleiotropic effects on different genes involved in the pathogenesis of lung cancer. In this narrative review, we presented the experimental and clinical studies that evaluated the effects of statins on lung cancer and described data on the effectiveness and safety of these compounds. We also evaluated gender differences in the treatment of lung cancer to understand the possibility of personalized therapy based on the modulation of the mevalonate pathway. In conclusion, according to the literature data, statins exert multiple effects on lung cancer cells, even if the evidence for their use in clinical practice is lacking.

Cholesterol-Lowering Phytochemicals: Targeting the Mevalonate Pathway for Anticancer Interventions

There are a plethora of cancer causes and the road to fully understanding the carcinogenesis process remains a dream that keeps changing. However, a list of role players that are implicated in the carcinogens process is getting lengthier. Cholesterol is known as bad sterol that is heavily linked with cardiovascular diseases; however, it is also comprehensively associated with carcinogenesis. There is an extensive list of strategies that have been used to lower cholesterol; nevertheless, the need to find better and effective strategies remains vastly important. The role played by cholesterol in the induction of the carcinogenesis process has attracted huge interest in recent years. Phytochemicals can be dubbed as magic tramp cards that humans could exploit for lowering cancer-causing cholesterol. Additionally, the mechanisms that are regulated by phytochemicals can be targeted for anticancer drug development. One of the key role players in cancer development and suppression, Tumour Protein 53 (TP53), is crucial in regulating the biogenesis of cholesterol and is targeted by several phytochemicals. This minireview covers the role of p53 in the mevalonate pathway and how bioactive phytochemicals target the mevalonate pathway and promote p53-dependent anticancer activities.