MiR-210 in exosomes derived from CAFs promotes non-small cell lung cancer migration and invasion through PTEN/PI3K/AKT pathway

ObjectiveCancer-associated fibroblasts (CAFs) function as a crucial factor in tumor progression by carrying exosomes to neighboring cells. This study was assigned to expound the underlying mechanism of CAFs-derived exosomal miR-210 in non-small cell lung cancer (NSCLC) progression.MethodCAFs and normal fibroblasts (NFs) were isolated and identified. Exosomes secreted from CAFs and NFs were isolated to analyze their effects on tumor volume and epithelial-mesenchymal transition (EMT). Exosomal miR-210 expression level was measured. The effects of exosomal miR-210 and UPF1 on cell viability, EMT, PTEN/PI3K/AKT signal pathway were determined. Dual-luciferase reporter gene assay was utilized to validate the binding of UPF1 to miR-210.ResultsCAFs-derived exosomes (CAFs-exo) were successfully extracted and proven to be uptake by lung cancer cells. Up-regulated expression level of miR-210 was found in CAFs-exo, which was then proved to enhance cell migration, proliferation, invasion abilities and EMT in NSCLC cells. Overexpression of miR-210 can also inhibit UPF1 and PTEN, but activate the PTEN/PI3K/AKT pathway. UPF1 was a target gene of miR-210. MiR-210 can up-regulate UPF1 expression level to activate PTEN/PI3K/AKT pathway.ConclusionMiR-210 secreted by CAFs-exo could promote EMT by targeting UPF1 and activating PTEN/PI3K/AKT pathway, thereby promoting NSCLC migration and invasion.     

Evidence that phosphatidylinositol 3-kinase- and mitogen-activated protein kinase kinase-4/c-Jun NH2-terminal kinase-dependent Pathways cooperate to maintain lung cancer cell survival

Cancer cells in which the PTEN lipid phosphatase gene is deleted have constitutively activated phosphatidylinositol 3-kinase (PI3K)-dependent signaling and require activation of this pathway for survival. In non-small cell lung cancer (NSCLC) cells, PI3K-dependent signaling is typically activated through mechanisms other than PTEN gene loss. The role of PI3K in the survival of cancer cells that express wild-type PTEN has not been defined. Here we provide evidence that H1299 NSCLC cells, which express wild-type PTEN, underwent proliferative arrest following treatment with an inhibitor of all isoforms of class I PI3K catalytic activity (LY294002) or overexpression of the PTEN lipid phosphatase. In contrast, overexpression of a dominant-negative mutant of the p85alpha regulatory subunit of PI3K (Deltap85) induced apoptosis. Whereas PTEN and Delta85 both inhibited activation of AKT/protein kinase B, only Deltap85 inhibited c-Jun NH2-terminal kinase (JNK) activity. Cotransfection of the constitutively active mutant Rac-1 (Val12), an upstream activator of JNK, abrogated Deltap85-induced lung cancer cell death, whereas constitutively active mutant mitogen-activated protein kinase kinase (MKK)-1 (R4F) did not. Furthermore, LY294002 induced apoptosis of MKK4-null but not wild-type mouse embryo fibroblasts. Therefore, we propose that, in the setting of wild-type PTEN, PI3K- and MKK4/JNK-dependent pathways cooperate to maintain cell survival.     

Atorvastatin overcomes gefitinib resistance in KRAS mutant human non-small cell lung carcinoma cells

The exact influence of statins on gefitinib resistance in human non-small cell lung cancer (NSCLC) cells with KRAS mutation alone or KRAS/PIK3CA and KRAS/PTEN comutations remains unclear. This work found that transfection of mutant KRAS plasmids significantly suppressed the gefitinib cytotoxicity in Calu3 cells (wild-type KRAS). Gefitinib disrupted the Kras/PI3K and Kras/Raf complexes in Calu3 cells, whereas not in Calu3 KRAS mutant cells. These trends were corresponding to the expression of pAKT and pERK in gefitinib treatment. Atorvastatin (1 μM) plus gefitinib treatment inhibited proliferation, promoted cell apoptosis, and reduced the AKT activity in KRAS mutant NSCLC cells compared with gefitinib alone. Atorvastatin (5 μM) further enhanced the gefitinib cytotoxicity through concomitant inhibition of AKT and ERK activity. Atorvastatin could interrupt Kras/PI3K and Kras/Raf complexes, leading to suppression of AKT and ERK activity. Similar results were also obtained in comutant KRAS/PTEN or KRAS/PIK3CA NSCLC cells. Furthermore, mevalonate administration reversed the effects of atorvastatin on the Kras/Raf and Kras/PI3K complexes, as well as AKT and ERK activity in both A549 and Calu1 cells. The in vivo results were similar to those obtained in vitro. Therefore, mutant KRAS-mediated gefitinib insensitivity is mainly derived from failure to disrupt the Kras/Raf and Kras/PI3K complexes in KRAS mutant NSCLC cells. Atorvastatin overcomes gefitinib resistance in KRAS mutant NSCLC cells irrespective of PIK3CA and PTEN statuses through inhibition of HMG-CoA reductase-dependent disruption of the Kras/Raf and Kras/PI3K complexes.     

The deubiquitinase USP10 restores PTEN activity and inhibits non–small cell lung cancer cell proliferation

The phosphatase and tensin homolog deleted on chromosome 10 (PTEN) protein is a key player in tumorigenesis of non–small cell lung cancer (NSCLC) and was recently found to be inactivated by tripartite motif containing 25 (TRIM25)–mediated K63-linked polyubiquitination. However, the deubiquitinase (Dub) coordinate TRIM25 in PTEN ubiquitination is still elusive. In the present study, we found that this K63-linked polyubiquitination could be ablated by the ubiquitin-specific protease 10 (USP10) in a screen against a panel of Dubs. We found using coimmununoprecipitation/immunoblotting that USP10 interacted with PTEN and reduced the K63-linked polyubiquitination of PTEN mediated by TRIM25 in NSCLC cells. Moreover, USP10, but not its inactive C424A deubiquitinating mutant or other Dubs, abolished PTEN from K63-linked polyubiquitination mediated by TRIM25. In contrast to TRIM25, USP10 restored PTEN phosphatase activity and reduced the production of the secondary messenger phosphatidylinositol-3,4,5-trisphosphate, thereby inhibiting AKT/mammalian target of rapamycin progrowth signaling transduction in NSCLC cells. Moreover, USP10 was downregulated in NSCLC cell lines and primary tissues, whereas TRIM25 was upregulated. Consistent with its molecular activity, re-expression of USP10 suppressed NSCLC cell proliferation and migration, whereas knockout of USP10 promoted NSCLC cell proliferation and migration. In conclusion, the present study demonstrates that USP10 coordinates TRIM25 to modulate PTEN activity. Specifically, USP10 activates PTEN by preventing its K63-linked polyubiquitination mediated by TRIM25 and suppresses the AKT/mammalian target of rapamycin signaling pathway, thereby inhibiting NSCLC proliferation, indicating that it may be a potential drug target for cancer treatment.     

RHCG基因在非小细胞肺癌中的表达及对细胞增殖的影响

为了探讨Rh type C glycoprotein (RHCG)对非小细胞肺癌(non-small cell lung cancer,NSCLC)细胞增殖的影响及可能的作用机制,本研究使用荧光定量PCR法检测12对NSCLC及癌旁组织样本中RHCG mRNA的表达水平及pcDNA3.1-RHCG质粒对A549细胞RHCG m RNA的表达;采用CCK-8法检测细胞增殖能力;运用PI染色法检测细胞周期;使用免疫印迹法检p-PI3K、PI3K、p-AKT以及AKT蛋白表达水平。本研究发现,与癌旁组织比较,NSCLC中RHCG m RNA表达水平明显降低。RHCG过表达能抑制NSCLC细胞系A549细胞增殖能力。此外,RHCG过表达使A549细胞周期G1/S期转化发生阻滞。本研究还发现,RHCG过表达可下调A549细胞p-PI3K/PI3K和p-AKT/AKT水平。本研究表明,RHCG抑制NSCLC细胞增殖的作用与其抑制PI3K/AKT信号通路有关。     

PPARbeta/delta agonist stimulates human lung carcinoma cell growth through inhibition of PTEN expression: the involvement of PI3K and NF-kappaB signals

Recent studies suggest that activation of peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) promotes cancer cell survival. We previously demonstrated that a selective PPARbeta/delta agonist, GW501516, stimulated human non-small cell lung carcinoma (NSCLC) cell growth. Here, we explore the mechanisms responsible for this effect. We show that GW501516 decreased phosphate and tensin homolog deleted on chromosome 10 (PTEN), a tumor suppressor known to decrease cell growth and induce apoptosis. Activation of PPARbeta/delta and phosphatidylinositol 3-kinase (PI3K)/Akt signaling was associated with inhibition of PTEN. GW501516 increased NF-kappaB DNA binding activity and p65 protein expression through activation of PPARbeta/delta and PI3K/Akt signals and enhanced the physical interactions between PPARbeta/delta and p65 protein. Conversely, inhibition of PI3K and silencing of p65 by small RNA interference (siRNA) blocked the effect of GW501516 on PTEN expression and on NSCLC cell proliferation. GW501516 also inhibited IKBalpha protein expression. Silencing of IKBalpha enhanced the effect of GW501516 on PTEN protein expression and on cell proliferation. It also augmented the GW501516-induced complex formation of PPARbeta/delta and p65 proteins. Overexpression of PTEN suppressed NSCLC cell growth and eliminated the effect of GW501516 on phosphorylation of Akt. Together, our observations suggest that GW501516 induces the proliferation of NSCLC cells by inhibiting the expression of PTEN through activation of PPARbeta/delta, which stimulates PI3K/Akt and NF-kappaB signaling. Overexpression of PTEN overcomes this effect and unveils PPARbeta/delta and PTEN as potential therapeutic targets in NSCLC.     

PI3K/PTEN/AKT signaling regulates prostate tumor angiogenesis

PI3K pathway exerts its function through its downstream molecule AKT in regulating various cell functions including cell proliferation, cell transformation, cell apoptosis, tumor growth and angiogenesis. PTEN is an inhibitor of PI3K, and its loss or mutation is common in human prostate cancer. But the direct role and mechanism of PI3K/PTEN signaling in regulating angiogenesis and tumor growth in vivo remain to be elucidated. In this study, by using chicken chorioallantoic membrane (CAM) and in nude mice models, we demonstrated that inhibition of PI3K activity by LY294002 decreased PC-3 cells-induced angiogenesis. Reconstitution of PTEN, the molecular inhibitor of PI3K in PC-3 cells inhibited angiogenesis and tumor growth. Immunohistochemical staining indicated that PTEN expression suppressed HIF-1, VEGF and PCNA expression in the tumor xenographs. Similarly, expression of AKT dominant negative mutant also inhibited angiogenesis and tumor growth, and decreased the expression of HIF-1 and VEGF in the tumor xenographs. These results suggest that inhibition of PI3K signaling pathway by PTEN inhibits tumor angiogenesis and tumor growth. In addition, we found that AKT is the downstream target of PI3K in controlling angiogenesis and tumor growth, and PTEN could inhibit angiogenesis by regulating the expression of HIF-1 and VEGF expression through AKT activation in PC-3 cells.     

Baicalein inhibits cell growth and increases cisplatin sensitivity of A549 and H460 cells via miR‐424‐3p and targeting PTEN/PI3K/Akt pathway

Lung cancer is the leading cause of death in individuals with malignant disease. Non‐small‐cell lung cancer (NSCLC) is the most common type of lung cancer, and chemotherapy drugs such as cisplatin are the most widely used treatment for this disease. Baicalein is a purified flavonoid compound that has been reported to inhibit cancer cell growth and metastasis and increase sensitization to chemotherapeutic drugs via different pathways. Therefore, we assessed the effects of baicalein on the proliferation, apoptosis and cisplatin sensitivity in the NSCLC A549 and H460 cell lines and determined the pathways through which baicalein exerts its effects. Baicalein was slightly toxic to normal human bronchial NHBE cells but inhibited growth, induced apoptosis and increased cisplatin sensitivity in A549 and H460 cells. Baicalein down‐regulated miR‐424‐3p, up‐regulated PTEN expression and down‐regulated expression of PI3K and p‐Akt in A549 and H460 cells. Dual‐luciferase reporter assay demonstrated that PTEN is a target gene of miR‐424‐3p, and overexpression of miR‐424‐3p or silencing of PTEN partially attenuated the effects of baicalein on A549 and H460 cells. Taken together, we concluded that baicalein inhibits cell growth and increases cisplatin sensitivity to A549 and H460 cells via down‐regulation of miR‐424‐3p and targeting the PTEN/PI3K/Akt pathway.     

PTEN promotes intervertebral disc degeneration by regulating nucleus pulposus cell behaviors

Intervertebral disc degeneration (IDD) is induced by multiple factors including increased apoptosis, decreased survival, and reduced extracellular matrix (ECM) synthesis in the nucleus pulposus (NP) cells. The tumor suppressor phosphatase and tensin homolog deleted from chromosome 10 (PTEN) is the only known lipid phosphatase counteracting the PI3K/AKT pathway. Loss of PTEN leads to activated PI3K/AKT signaling, which plays a key role in a variety of cancers. However, the role of PTEN/PI3K/AKT signaling nexus in IDD remains unknown. Here, we report that PTEN is overexpressed in degenerative NP, which correlates with inactivated AKT. Using the PTEN knockdown approach by lentivirus‐mediated short interfering RNA gene transfer technique, we report that PTEN decreases survival but induces apoptosis and senescence of NP cells. PTEN also inhibits expression and production of ECM components including collagen II, aggrecan, and proteoglycan. Furthermore, PTEN modulates the expression of ECM regulatory molecules SOX‐9 and matrix metalloproteinase‐3 (MMP‐3). Using small‐molecule AKT inhibitor GDC‐0068, we confirm that PTEN regulates NP cell behaviors through its direct targeting of PI3K/AKT. These findings demonstrate for the first time that PTEN/PI3K/AKT signaling axis plays an important role in the pathogenesis of IDD. Targeting PTEN using gene therapy may represent a promising therapeutic approach against disc degenerative diseases.     

Biphasic estradiol-induced AKT phosphorylation is modulated by PTEN via MAP kinase in HepG2 cells

We reported previously in HepG2 cells that estradiol induces cell cycle progression throughout the G1-S transition by the parallel stimulation of both PKC-alpha and ERK signaling molecules. The analysis of the cyclin D1 gene expression showed that only the MAP kinase pathway was involved. Here, the presence of rapid/nongenomic, estradiol-regulated, PI3K/AKT signal transduction pathway, its modulation by the levels of the tumor suppressor PTEN, its cross-talk with the ERK pathway, and its involvement in DNA synthesis and cyclin D1 gene promoter activity have all been studied in HepG2 cells. 17beta-Estradiol induced the rapid and biphasic phosphorylation of AKT. These phosphorylations were independent of each other, being the first wave of activation independent of the estrogen receptor (ER), whereas the second was dependent on ER. Both activations were dependent on PI3K activity; furthermore, the ERK pathway modulated AKT phosphorylation by acting on the PTEN levels. The results showed that the PI3K pathway, as well as ER, were strongly involved in both G1-S progression and cyclin D1 promoter activity by acting on its proximal region (-254 base pairs). These data indicate that in HepG2 cells, different rapid/nongenomic estradiol-induced signal transduction pathways modulate the multiple steps of G1-S phase transition.     

Candidate tumour suppressor CCDC19 regulates miR‐184 direct targeting of C‐Myc thereby suppressing cell growth in non‐small cell lung cancers

We previously reported and revised the nasopharyngeal epithelium specific protein CCDC19 and identified it as a potential tumour suppressor in nasopharyngeal carcinoma. The purpose of this study was to investigate the involvement of CCDC19 in the pathogenesis of human non‐small cell lung cancers (NSCLC). Down‐regulated CCDC19 expression was observed in NSCLC tissues and cells compared to normal tissues. However, reduced protein expression did not correlate with the status of NSCLC progression. Instead, we observed that patients with lower CCDC19 expression had a shorter overall survival than did patients with higher CCDC19 expression. Lentiviral‐mediated CCDC19 overexpression significantly suppressed cell proliferation and cell cycle transition from G1 to S and G2 phases in NSCLC cells. Knocking down CCDC19 expression significantly restored the ability of cell growth in CCDC19 overexpressing NSCLC cells. Mechanistically CCDC19 functions as a potential tumour suppressor by stimulating miR‐184 suppression of C‐Myc thus blocking cell growth mediated by the PI3K/AKT/C‐Jun pathway. Our studies are the first to demonstrate that reduced expression of CCDC19 is an unfavourable factor in NSCLC.     

Timosaponin AIII inhibits metastasis of renal carcinoma cells through suppressing cathepsin C expression by AKT/miR-129-5p axis

Timosaponin AIII (TSAIII) is a steroidal saponin that exerts anticancer activity on various cancer cells. In this study, we explore the effects of TSAIII on renal cell carcinoma (RCC) cells. Our findings show that TSAIII treatment (<8 μM) insignificantly influenced cell viability and cell cycle distribution of human RCC cell lines 786-O, A-498, and ACHN. Further observations revealed that TSAIII inhibited migration and invasion of 786-O and A-498 cells, as well as significantly decreased the production and expression of cathepsin C (CTSC) in both the cell types. Kinase cascade analysis exhibited that PI3K/AKT activation was inhibited, but PTEN expression was increased, in response to TSAIII treatments. Combining TSAIII and PI3K inhibitors, LY294002 synergically reduced the migration and invasion of 786-O and A-498 cells, as well as decreased the CTSC expression in both the cell types. We also observed that miR-129-5p bound to CTSC gene and suppressed the expression of CTSC and demonstrated that the miR-129-5p expression was synergically enhanced by TSAIII and LY294002. In addition, pretreatment with antago-miR-129-5p significantly restored the CTSC expression and the migration and invasion of TSAIII-treated 786-O cells. In conclusion, our findings reveal that TSAIII inhibits the metastatic properties of RCC cells, contributing to the inhibition of PI3K/AKT and the increase of miR-129-5p and the subsequent downregulation of CTSC. This suggests that TSAIII has significant antimetastatic activity against RCC cells and may be beneficial to RCC treatments.     

Variable Expression of PIK3R3 and PTEN in Ewing Sarcoma Impacts Oncogenic Phenotypes

Ewing Sarcoma is an aggressive malignancy of bone and soft tissue affecting children and young adults. Ewing Sarcoma is driven by EWS/Ets fusion oncoproteins, which cause widespread alterations in gene expression in the cell. Dysregulation of receptor tyrosine kinase signaling, particularly involving IGF-1R, also plays an important role in Ewing Sarcoma pathogenesis. However, the basis of this dysregulation, including the relative contribution of EWS/Ets-dependent and independent mechanisms, is not well understood. In the present study, we identify variable expression of two modifiers of PI3K signaling activity, PIK3R3 and PTEN, in Ewing Sarcoma, and examine the consequences of this on PI3K pathway regulation and oncogenic phenotypes. Our findings indicate that PIK3R3 plays a growth-promotional role in Ewing Sarcoma, but suggest that this role is not strictly dependent on regulation of PI3K pathway activity. We further show that expression of PTEN, a well-established, potent tumor suppressor, is lost in a subset of Ewing Sarcomas, and that this loss strongly correlates with high baseline PI3K pathway activity in cell lines. In support of functional importance of PTEN loss in Ewing Sarcoma, we show that re-introduction of PTEN into two different PTEN-negative Ewing Sarcoma cell lines results in downregulation of PI3K pathway activity, and sensitization to the IGF-1R small molecule inhibitor OSI-906. Our findings also suggest that PTEN levels may contribute to sensitivity of Ewing Sarcoma cells to the microtubule inhibitor vincristine, a relevant chemotherapeutic agent in this cancer. Our studies thus identify PIK3R3 and PTEN as modifiers of oncogenic phenotypes in Ewing Sarcoma, with potential clinical implications.     

PI3K/AKT途径在大肠埃希菌诱导U937细胞凋亡中的作用

目的探讨PI3K/AKT信号转导通路在大肠埃希菌（Escherichia coli,E.coli）诱导的人巨噬细胞系U937细胞凋亡中的作用。方法利用Western blot分析检测E.coli感染不同时间后磷酸化及非磷酸化AKT的表达;预先用不同浓度的LY294002（PI3K途径抑制剂）处理U937细胞60min,观察E.coli感染30min后U937细胞的凋亡情况。结果随着感染时间的延长,磷酸化AKT的表达逐渐下降。加入PI3K的抑制剂LY294002后,U937细胞的凋亡率逐渐升高。结论PI3K/AKT信号转导通路参与了E. coli诱导的U937细胞凋亡过程。LY294002通过特异性地抑制PI3K/AKT活性增加E.coli诱导的U937细胞凋亡率。     

Src family protein-tyrosine kinases alter the function of PTEN to regulate phosphatidylinositol 3-kinase/AKT cascades

Src family protein-tyrosine kinases, which play an important role in signal integration, have been implicated in tumorigenesis in multiple lineages, including breast cancer. We demonstrate, herein, that Src kinases regulate the phosphatidylinositol 3-kinase (PI3K) signaling cascade via altering the function of the PTEN tumor suppressor. Overexpression of activated Src protein-tyrosine kinases in PTEN-deficient breast cancer cells does not alter AKT phosphorylation, an indicator of signal transduction through the PI3K pathway. However, in the presence of functional PTEN, Src reverses the activity of PTEN, resulting in an increase in AKT phosphorylation. Activated Src reduces the ability of PTEN to dephosphorylate phosphatidylinositols in micelles and promotes AKT translocation to cellular plasma membranes but does not alter PTEN activity toward water-soluble phosphatidylinositols. Thus, Src may alter the capacity of the PTEN C2 domain to bind cellular membranes rather than directly interfering with PTEN enzymatic activity. Tyrosine phosphorylation of PTEN is increased in breast cancer cells treated with pervanadate, suggesting that PTEN contains sites for tyrosine phosphorylation. Src kinase inhibitors markedly decreased pervanadate-mediated tyrosine phosphorylation of PTEN. Further, expression of activated Src results in marked tyrosine phosphorylation of PTEN. SHP-1, a SH2 domain-containing protein-tyrosine phosphatase, selectively binds and dephosphorylates PTEN in Src transfected cells. Both Src inhibitors and SHP-1 overexpression reverse Src-induced loss of PTEN function. Coexpression of PTEN with activated Src reduces the stability of PTEN. Taken together, the data indicate that activated Src inhibits PTEN function leading to alterations in signaling through the PI3K/AKT pathway.     

Stable overexpression of mutated PTEN in Chinese hamster ovary cells enhances their performance and therapeutic antibody production

Chinese hamster ovary (CHO) cells with a high viable cell density (VCD), resilience to culture stress, and the capacity to continuously express recombinant proteins are highly desirable. Phosphatase and tension homology deleted on chromosome ten (PTEN) functions as a key negative regulator of the PI3K/Akt signaling pathway, mediating cell growth and survival. Its oncogenic mutant endows cells with an enhanced proliferation rate and resistance to death. In this study, the role of oncogenic PTEN C124S or G129E on the performance of CHO-K1 and CHO-IgG cells was investigated. Our results showed that CHO-K1 cells stably expressing PTEN C124S or G129E exhibited enhanced proliferation, reduced apoptosis rate, and increased transient expression of therapeutic antibodies compared to the control cells. Moreover, the stable overexpression of PTEN C124S or G129E endowed CHO-IgG cells with higher cell viability, VCD, and antibody titers (yield increased by approximately 0.77-fold) in the fed-batch culture process and enhanced their performance in response to the addition of sodium lactate. Moreover, the engineering of mutated PTEN in CHO-IgG cells did not alter antibody quality. Collectively, our data suggest that mutated PTEN is a potential target for improving the manufacture of therapeutic antibodies.     

Statin induces inhibition of triple negative breast cancer (TNBC) cells via PI3K pathway

Primary TNBCs are treated as if they were a single disease entity, yet it is clear they do not behave as a single entity in response to current therapies. Recently, we reported that statins might have a potential benefit for TNBCs associated with ets-1 overexpression. The aim of this study is to investigate the role of PTEN loss in the effects of statin on TNBC cells. In addition, we analyze the relationship between AKT downstream pathways and the effects of statin on TNBC cells. We investigated the effect of a statin on TNBC cells and analyzed the association of PI3K pathways using various TNBC cells in terms of PTEN loss and AKT pathways. Simvastatin treatments resulted in decreased cell viabilities in various TNBC cell lines. Compared with PTEN wild-type TNBC cells, PTEN mutant-type TNBC cells showed a decreased response to simvastatin. Expressions of phosphorylated Akt and total Akt showed an inverse relationship with PTEN expression. The TNBC cell lines, which showed increased expression of p-Akt, appeared to attenuate the expression of p-Akt by PTEN loss in simvastatin-treated TNBC cells. The Akt inhibitor, LY294002, augmented the effect of simvastatin on PTEN wild-type TNBC cells. Simvastatin induces inhibition of TNBC cells via PI3K pathway activation.