Targeting PI3K/AKT/mTOR Signaling Pathway in Breast Cancer

Biologically synthesized black ginger-selenium nanoparticle induces apoptosis and autophagy of AGS gastric cancer cells by suppressing the PI3K/Akt/mTOR signaling pathway

BACKGROUND

Despite being a promising strategy, current chemotherapy for gastric cancer (GC) is limited due to adverse side effects and poor survival rates. Therefore, new drug-delivery platforms with good biocompatibility are needed. Recent studies have shown that nanoparticle-based drug delivery can be safe, eco-friendly, and nontoxic making them attractive candidates. Here, we develop a novel selenium-nanoparticle based drug-delivery agent for cancer treatment from plant extracts and selenium salts.

RESULTS

Selenium cations were reduced to selenium nanoparticles using Kaempferia parviflora (black ginger) root extract and named KP-SeNP. Transmission electron microscopy, selected area electron diffraction, X-ray diffraction, energy dispersive X-ray, dynamic light scattering, and Fourier-transform infrared spectrum were utilized to confirm the physicochemical features of the nanoparticles. The KP-SeNPs showed significant cytotoxicity in human gastric adenocarcinoma cell (AGS cells) but not in normal cells. We determined that the intracellular signaling pathway mechanisms associated with the anticancer effects of KP-SeNPs involve the upregulation of intrinsic apoptotic signaling markers, such as B-cell lymphoma 2, Bcl-associated X protein, and caspase 3 in AGS cells. KP-SeNPs also caused autophagy of AGS by increasing the autophagic flux-marker protein, LC3B-II, whilst inhibiting autophagic cargo protein, p62. Additionally, phosphorylation of PI3K/Akt/mTOR pathway markers and downstream targets was decreased in KP-SeNP-treated AGS cells. AGS-cell xenograft model results further validated our in vitro findings, showing that KP-SeNPs are biologically safe and exert anticancer effects via autophagy and apoptosis.

CONCLUSIONS

These results show that KP-SeNPs treatment of AGS cells induces apoptosis and autophagic cell death through the PI3K/Akt/mTOR pathway, suppressing GC progression. Thus, our research strongly suggests that KP-SeNPs could act as a novel potential therapeutic agent for GC.

Signaling pathways and therapeutic interventions in gastric cancer

Gastric cancer (GC) ranks fifth in global cancer diagnosis and fourth in cancer-related death. Despite tremendous progress in diagnosis and therapeutic strategies and significant improvements in patient survival, the low malignancy stage is relatively asymptomatic and many GC cases are diagnosed at advanced stages, which leads to unsatisfactory prognosis and high recurrence rates. With the recent advances in genome analysis, biomarkers have been identified that have clinical importance for GC diagnosis, treatment, and prognosis. Modern molecular classifications have uncovered the vital roles that signaling pathways, including EGFR/HER2, p53, PI3K, immune checkpoint pathways, and cell adhesion signaling molecules, play in GC tumorigenesis, progression, metastasis, and therapeutic responsiveness. These biomarkers and molecular classifications open the way for more precise diagnoses and treatments for GC patients. Nevertheless, the relative significance, temporal activation, interaction with GC risk factors, and crosstalk between these signaling pathways in GC are not well understood. Here, we review the regulatory roles of signaling pathways in GC potential biomarkers, and therapeutic targets with an emphasis on recent discoveries. Current therapies, including signaling-based and immunotherapies exploited in the past decade, and the development of treatment for GC, particularly the challenges in developing precision medications, are discussed. These advances provide a direction for the integration of clinical, molecular, and genomic profiles to improve GC diagnosis and treatments.

Regulation of Signaling from the Epidermal Growth Factor Family

The epidermal growth factor (EGF) system has allowed chemists, biologists, and clinicians to improve our understanding of cell production and cancer therapy. The discovery of EGF led to the recognition of cell surface receptors capable of controlling the proliferation and survival of cells. The detailed structures of the EGF-like ligand and the responses of their receptors (EGFR-family) has revealed the conformational and aggregation changes whereby ligands activate the intracellular kinase domains. Biophysical analysis has revealed the preformed clustering of different EGFR-family members and the processes which occur on ligand binding. Understanding these receptor activation processes and the consequential cytoplasmic signaling has allowed the development of inhibitors which are revolutionizing cancer therapy. This Review describes the recent progress in our understanding of the activation of the EGFR-family, the effects of signaling from the EGFR-family on cell proliferation, and the targeting of the EGFR-family in cancer treatment.

PI3K/mTOR Dual Inhibitor Pictilisib Stably Binds to Site I of Human Serum Albumin as Observed by Computer Simulation, Multispectroscopic, and Microscopic Studies

Pictilisib (GDC-0941) is a well-known dual inhibitor of class I PI3K and mTOR and is presently undergoing phase 2 clinical trials for cancer treatment. The present work investigated the dynamic behaviors and interaction mechanism between GDC-0941 and human serum albumin (HSA). Molecular docking and MD trajectory analyses revealed that GDC-0941 bound to HSA and that the binding site was positioned in subdomain IIA at Sudlow’s site I of HSA. The fluorescence intensity of HSA was strongly quenched by GDC-0941, and results showed that the HSA–GDC-0941 interaction was a static process caused by ground-state complex formation. The association constant of the HSA–GDC-0941 complex was approximately 10⁵ M⁻¹, reflecting moderate affinity. Thermodynamic analysis conclusions were identical with MD simulation results, which revealed that van der Waals interactions were the vital forces involved in the binding process. CD, synchronous, and 3D fluorescence spectroscopic results revealed that GDC-0941 induced the structural change in HSA. Moreover, the conformational change of HSA affected its molecular sizes, as evidenced by AFM. This work provides a useful research strategy for exploring the interaction of GDC-0941 with HSA, thus helping in the understanding of the transport and delivery of dual inhibitors in the blood circulation system.

Zearalenone affects the growth of endometriosis via estrogen signaling and inflammatory pathways

Endometriosis is a chronic, inflammatory, estrogen-dependent gynecological disease characterized by the growth of endometrial stromal cells and glands outside the uterine cavity in response to hormones, which commonly occurs in reproductive-age women. Zearalenone (ZEA) is a toxic metabolite produced by Fusarium, which acts as estrogen activity because of the similarity of its structure to estrogen. In this study, we used an endometriosis mouse model: 15 days after ovariectomy, endometrial fragments were sutured on the pelvic wall, and exogenous estrogen was supplied using an estrogen-releasing silicone tube embedded subcutaneously. Mice were treated with different doses of ZEA by gavage for 21 days. The results show that ZEA significantly inhibited the growth of ectopic endometrium in a dose-dependent manner. The proliferation of cells decreased while apoptosis increased in the ectopic tissues of ZEA-treated mice compared to the vehicle group. The expression of estrogen receptor-α and its downstream targets MUC1 and p-AKT decreased, indicating an impaired estrogen signaling activity by ZEA treatment. In addition, the decreased expression of pro-inflammatory cytokine Tnf-α, Il-1β, and Il-6, the lower number of macrophages and neutrophils cells, and the inhibited NF-κB signaling pathway suggest the inflammatory response in the ectopic endometrium was also suppressed by ZEA treatment. However, when the exogenous estrogen supply is removed, ZEA, in turn, plays an estrogen-like role that promotes cell proliferation in the ectopic endometrium. In summary, our data suggest ZEA acts as an antagonist in endometriotic tissue when estrogen is sufficient but turns to estrogenic activity in the absence of estrogen in the development of endometriosis. ZEA also inhibits ectopic tissue growth by inhibiting inflammatory response in the endometriosis model.

Expert consensus on the clinical application of PI3K/AKT/mTOR inhibitors in the treatment of advanced breast cancer

Phosphoinositide 3-kinase (PI3K)/protein kinase B (PKB or AKT)/mammalian target of rapamycin (mTOR) signaling pathway (PAM pathway) plays an important role in the development of breast cancer and are closely associated with the resistance to endocrine therapy in advanced breast cancer. Therefore, anticancer treatment targeting key molecules in this signaling pathway has become a research hotspot in recent years. Randomized clinical trials have demonstrated that PI3K/AKT/mTOR inhibitors bring significant clinical benefit to patients with advanced breast cancer, especially to those with hormone receptor (HR)-positive, human epidermal growth factor receptor (HER) 2-negative advanced breast cancer. Alpelisib, a PI3K inhibitor, and everolimus, an mTOR inhibitor, have been approved by FDA. Based on their high efficacy and relatively good safety profile, an expanded indication of everolimus in breast cancer has been approved by National Medical Products Administration (NMPA). Alpelisib is expected to be approved in China in the near future. The members of the consensus expert panel reached this consensus to comprehensively define the role of PI3K/AKT/mTOR signaling pathway in breast cancer, efficacy and clinical applications of PI3K/AKT/mTOR inhibitors, management of adverse reactions, and PIK3CA mutation detection, to promote the understanding of PI3K/AKT/mTOR inhibitors for Chinese oncologists, improve clinical decision-making, and prolong the survival of target patient population.

Crosstalk between PI3K/AKT/mTOR and WNT/β-Catenin signaling in GBM - Could combination therapy checkmate the collusion?

Glioblastoma multiforme is one of the calamitous primary glial brain tumors with extensive heterogeneity at cellular and molecular levels. While maximal surgical resection trailed by radio and chemotherapy employing temozolomide remains the gold-standard treatment for malignant glioma patients, the overall prognosis remains dismal and there exists an unmet need for effective therapeutic strategies. In this context, we hypothesize that proper understanding of signaling pathways responsible for glioblastoma multiforme proliferation would be the first trump card while searching for novel targeted therapies. Among the pathways aberrantly activated, PI3K/AKT/mTOR is the most significant pathway, that is clinically implicated in malignancies such as high-grade glioma. Further, the WNT/β-Catenin cascade is well-implicated in several malignancies, while its role in regulating glioma pathogenesis has only emerged recently. Nevertheless, oncogenic activation of both these pathways is a frequent event in malignant glioma that facilitates tumor proliferation, stemness and chemo-resistance. Recently, it has been reported that the cross-talk of PI3K/AKT/mTOR pathway with multiple signaling pathways could promote glioma progression and reduce the sensitivity of glioma cells to the standard therapy. However, very few studies had focused on the relationship between PI3K/AKT/mTOR and WNT/β-Catenin pathways in glioblastoma multiforme. Interestingly, in homeostatic and pathologic circumstances, both these pathways depict fine modulation and are connected at multiple levels by upstream and downstream effectors. Thus, gaining deep insights on the collusion between these pathways would help in discovering unique therapeutic targets for glioblastoma multiforme management. Hence, the current review aims to address, "the importance of inter-play between PI3K/AKT/mTOR and WNT/β-Catenin pathways", and put forward, "the possibility of combinatorially targeting them", for glioblastoma multiforme treatment enhancement.

LncRNA MNX1-AS1: A novel oncogenic propellant in cancers

To date, recent studies have shown that long non-coding RNAs (lncRNAs) are key players in gene regulation processes involved in cancer pathogenesis. In general, Motor neuron and pancreas homeobox 1-antisense RNA1 (MNX1-AS1) is highly expressed in all cancers as reported so far and exerts oncogenic effects through different mechanisms. In this review, we comprehensively summarize the detailed mechanisms of potential functions of MNX1-AS1 in different cancer types as well as the latest knowledge highlighting the potential of MNX1-AS1 as a therapeutic target for cancer. Aberrant expression of MNX1-AS1 closely correlates with clinicopathological parameters. such as lymphatic metastasis, tumor size, tumor stage, OS and DFS. Thus, MNX1-AS1 can be used as a diagnostic and prognostic biomarker or even a therapeutic prognostic target. This article reviews its function, molecular mechanism and clinical prognosis in various malignancies.

PI3K Inhibitors in Advanced Breast Cancer: The Past, The Present, New Challenges and Future Perspectives

Breast cancer is the leading cause of death in the female population and despite significant efforts made in diagnostic approaches and treatment strategies adopted for advanced breast cancer, the disease still remains incurable. Therefore, development of more effective systemic treatments constitutes a crucial need. Recently, several clinical trials were performed to find innovative predictive biomarkers and to improve the outcome of metastatic breast cancer through innovative therapeutic algorithms. In the pathogenesis of breast cancer, the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (PKB/AKT)-mammalian target of rapamycin (mTOR) axis is a key regulator of cell proliferation, growth, survival, metabolism, and motility, making it an interest and therapeutic target. Nevertheless, the PI3K/AKT/mTOR cascade includes a complex network of biological events, needing more sophisticated approaches for their use in cancer treatment. In this review, we described the rationale for targeting the PI3K pathway, the development of PI3K inhibitors and the future treatment directions of different breast cancer subtypes in the metastatic setting.

Role of PI3K/Akt/mTOR pathway in mediating endocrine resistance: concept to clinic

The majority of breast cancers express the estrogen receptor (ER) and for this group of patients, endocrine therapy is the cornerstone of systemic treatment. However, drug resistance is common and a focus for breast cancer preclinical and clinical research. Over the past 2 decades, the PI3K/Akt/mTOR axis has emerged as an important driver of treatment failure, and inhibitors of mTOR and PI3K are now licensed for the treatment of women with advanced ER-positive breast cancer who have relapsed on first-line hormonal therapy. This review presents the preclinical and clinical data that led to this new treatment paradigm and discusses future directions.

Chrysin Attenuates High Glucose-Induced BMSC Dysfunction via the Activation of the PI3K/AKT/Nrf2 Signaling Pathway

Purpose

High glucose environment in diabetes mellitus induces the dysfunction of bone marrow-derived mesenchymal stromal cells (BMSCs) and impairs bone regeneration. Chrysin is a natural polyphenol with outstanding anti-inflammation and anti-oxidation ability. However, whether and how chrysin affects BMSCs in high glucose conditions remain poorly understood. The present study aimed to explore the effects and underlying mechanisms of chrysin on the BMSCs exposed to high glucose environment.

Materials and Methods

Cell viability was detected by cell counting kit 8 assay and 5-ethynyl-2’-deoxyuridine staining, while cell apoptosis was determined through flow cytometry using Annexin V-FITC/PI kit. The oxidative stress in BMSCs was evaluated by detecting the reactive oxygen species production, malondialdehyde content, and superoxide dismutase activity. Alkaline phosphatase staining, Alizarin Red staining, and quantitative real-time PCR were performed to determine the osteogenic differentiation. Western blot was used to examine the expression of the PI3K/ATK/Nrf2 signaling pathway. Furthermore, chrysin was injected into calvarial defects of type 1 diabetic SD rats to assess its in vivo bone formation capability.

Results

Chrysin reduced oxidative stress, increased cell viability, and promoted osteogenic differentiation in BMSCs exposed to high glucose. Blocking PI3K/ATK/Nrf2 signaling pathway weakened the beneficial effects of chrysin, indicating that chrysin at least partly worked through the PI3K/ATK/Nrf2 pathway.

Conclusion

Chrysin can protect BMSCs from high glucose-induced oxidative stress via the activation of the PI3K/AKT/Nrf2 pathway, and promote bone regeneration in type 1 diabetic rats.

PIK3CA-AKT pathway predominantly acts in developing ipsilateral breast tumor recurrence long after breast-conserving surgery

PURPOSE

Ipsilateral breast tumor recurrence (IBTR) after breast-conserving therapy is seen after a long interval, but the clinical classification of Residual Tumor Recurrence (RR) or Double Primary (DP) needs to be validated. We used genome profiling to identify the genetic alterations associated with IBTR.

METHODS

Among 1881 breast cancer patients treated with breast-conserving therapy between 1999 and 2018, IBTR occurred in 52 patients (2.8%). Of these 22 patients who consented for genomic analysis of Primary Breast Cancer (T1) and IBTR (T2) were studied. When the same gene mutations in T1 and T2 were identified, it was classified as genomic residual recurrence gRR, and when no shared mutations identified, it was classified as gDP. The differences between clinical and genomic classification were compared. Furthermore, the pathway of the genes which were responsible for recurrence was also examined.

RESULTS

Of 13 clinically diagnosed RRs (cRRs), 11 were gRR and 2 were gDPs, while of 9 cDPs, 6 were gDP and 3 gRR, with a match rate of 17/22 (77%). We searched for genes involved in IBTR: PIK3CA-AKT pathway mutations were found in 12 of 14 gRRs (86%) in T1, and only 2 of 8 gDPs (25%) with significant difference (p = 0.004). When both of PBC and IBTR compared, PIK3CA-AKT pathway abnormalities were 24/28 (86%) in the gRR and 5/16 (31%) in the gDP (p < 0.001).

CONCLUSIONS

Genome profiling revealed that abnormalities in the PIK3CA-AKT pathway in long-term residential recurrences and are a crucial molecular group in the development of IBTR.

PI3K/Akt/mTOR Pathway and Its Role in Cancer Therapeutics: Are We Making Headway?

Cancer is a severe public health issue that is a leading cause of mortality globally. It is also an impediment to improving life expectancy worldwide. Furthermore, the global burden of cancer incidence and death is continuously growing. Current therapeutic options are insufficient for patients, and tumor complexity and heterogeneity necessitate customized medicine or targeted therapy. It is critical to identify potential cancer therapeutic targets. Aberrant activation of the PI3K/AKT/mTOR pathway has a significant role in carcinogenesis. This review summarized oncogenic PI3K/Akt/mTOR pathway alterations in cancer and various cancer hallmarks associated with the PI3K/AKT/mTOR pathway, such as cell proliferation, autophagy, apoptosis, angiogenesis, epithelial-to-mesenchymal transition (EMT), and chemoresistance. Importantly, this review provided recent advances in PI3K/AKT/mTOR inhibitor research. Overall, an in-depth understanding of the association between the PI3K/AKT/mTOR pathway and tumorigenesis and the development of therapies targeting the PI3K/AKT/mTOR pathway will help make clinical decisions.

Breast Cancer Stem-Like Cells in Drug Resistance: A Review of Mechanisms and Novel Therapeutic Strategies to Overcome Drug Resistance

Breast cancer is the most frequent type of malignancy in women worldwide, and drug resistance to the available systemic therapies remains a major challenge. At the molecular level, breast cancer is heterogeneous, where the cancer-initiating stem-like cells (bCSCs) comprise a small yet distinct population of cells within the tumor microenvironment (TME) that can differentiate into cells of multiple lineages, displaying varying degrees of cellular differentiation, enhanced metastatic potential, invasiveness, and resistance to radio- and chemotherapy. Based on the expression of estrogen and progesterone hormone receptors, expression of human epidermal growth factor receptor 2 (HER2), and/or BRCA mutations, the breast cancer molecular subtypes are identified as TNBC, HER2 enriched, luminal A, and luminal B. Management of breast cancer primarily involves resection of the tumor, followed by radiotherapy, and systemic therapies including endocrine therapies for hormone-responsive breast cancers; HER2-targeted therapy for HER2-enriched breast cancers; chemotherapy and poly (ADP-ribose) polymerase inhibitors for TNBC, and the recent development of immunotherapy. However, the complex crosstalk between the malignant cells and stromal cells in the breast TME, rewiring of the many different signaling networks, and bCSC-mediated processes, all contribute to overall drug resistance in breast cancer. However, strategically targeting bCSCs to reverse chemoresistance and increase drug sensitivity is an underexplored stream in breast cancer research. The recent identification of dysregulated miRNAs/ncRNAs/mRNAs signatures in bCSCs and their crosstalk with many cellular signaling pathways has uncovered promising molecular leads to be used as potential therapeutic targets in drug-resistant situations. Moreover, therapies that can induce alternate forms of regulated cell death including ferroptosis, pyroptosis, and immunotherapy; drugs targeting bCSC metabolism; and nanoparticle therapy are the upcoming approaches to target the bCSCs overcome drug resistance. Thus, individualizing treatment strategies will eliminate the minimal residual disease, resulting in better pathological and complete response in drug-resistant scenarios. This review summarizes basic understanding of breast cancer subtypes, concept of bCSCs, molecular basis of drug resistance, dysregulated miRNAs/ncRNAs patterns in bCSCs, and future perspective of developing anticancer therapeutics to address breast cancer drug resistance.

CIP2A as a Key Regulator for AKT Phosphorylation Has Partial Impact Determining Clinical Outcome in Breast Cancer

Together with its reported ability to modulate AKT phosphorylation (p-AKT) status in several tumor types, the oncoprotein CIP2A has been described to induce breast cancer progression and drug resistance. However, the clinical and therapeutic relevance of the CIP2A/AKT interplay in breast cancer remains to be fully clarified. Here, we found high p-AKT levels in 80 out of 220 cases (36.4%), which were associated with negative estrogen receptor expression (p = 0.049) and CIP2A overexpression (p < 0.001). Interestingly, p-AKT determined substantially shorter overall (p = 0.002) and progression-free survival (p = 0.003), and multivariate analyses showed its CIP2A-independent prognostic value. Moreover, its clinical relevance was further confirmed in the triple negative and HER2-positive subgroups after stratifying our series by molecular subtype. Functionally, we confirmed in vitro the role of CIP2A as a regulator of p-AKT levels in breast cancer cell lines, and the importance of the CIP2A/AKT axis was also validated in vivo. Finally, p-AKT also showed a higher predictive value of response to doxorubicin than CIP2A in ex vivo analyses. In conclusion, our findings suggest that CIP2A overexpression is a key contributing event to AKT phosphorylation and highlights the CIP2A/AKT axis as a promising therapeutic target in breast cancer. However, our observations highlight the existence of alternative mechanisms that regulate AKT signaling in a subgroup of breast tumors without altered CIP2A expression that determines its independent value as a marker of poor outcome in this disease.

Clinical study on Yanghe decoction in improving neo-adjuvant chemotherapy efficacy and immune function of breast cancer patients

INTRODUCTION

Neoadjuvant chemotherapy (NAC) plays an important role in downgrading preoperative tumor size, providing information on regimen activity, and increases treatment efficacy in breast cancer patients. An increasing number of patients have sought Traditional Chinese Medicine (TCM) during NAC to relieve discomfort, regulate immune function, and improve survival. However, limited evidence is available on how concurrent TCM treatment combined with NAC affects tumor response. This study aims to assess the efficacy of Yanghe decoction, a classical warming Yang formula, on pathological complete response (pCR) and explore its mechanism via the phosphatidylinositol-3-kinase/ protein kinase B/nuclear factor kappa-B (PI3K/Akt/NF-κB) pathway-mediated immune-inflammation microenvironment.

METHODS

A single-center, randomized, placebo-controlled, double-blinded randomized control trial (RCT) was designed. This trial aims to recruit 128 participants with breast cancer scheduled to receive NAC in China. All participants will be randomly assigned (1:1) to the Neo-Yanghe group (Yanghe decoction plus NAC) or the control group (placebo plus NAC). The primary outcome will be evaluated by the proportion of participants achieving pCR. The secondary outcomes include the expression level of PI3K/Akt/NF-κB pathway-related proteins, the objective response rate, the time to response, serum level of immune-inflammatory indicators, quality of life, disease-free survival, and overall survival.

DISCUSSION

This study will be the first RCT to evaluate the efficacy of Yanghe decoction combined with NAC in treating breast cancer patients, and elucidate the antitumor mechanism via the PI3K/Akt/NF-κB pathway-mediated immune-inflammation microenvironment. If possible, Neo-Yanghe treatment pattern will be a better pharmacological intervention to manage breast cancer than chemotherapy alone. The results of the trial will provide research-based evidence for the development of integrated Chinese and Western medicine guidelines and expert consensus.Trial registration: Chinese Clinical Trial Registry ChiCTR-INR-2000036943. Registered on September 28, 2020 (https://www.chictr.org.cn/hvshowproject.aspx?id=57141).

Promoting Apoptosis, a Promising Way to Treat Breast Cancer With Natural Products: A Comprehensive Review

Breast cancer is one of the top-ranked malignant carcinomas associated with morbidity and mortality in women worldwide. Chemotherapy is one of the main approaches to breast cancer treatment. Breast cancer initially responds to traditional first- and second-line drugs (aromatase inhibitor, tamoxifen, and carboplatin), but eventually acquires resistance, and certain patients relapse within 5 years. Chemotherapeutic drugs also have obvious toxic effects. In recent years, natural products have been widely used in breast cancer research because of their low side effects, low toxicity, and good efficacy based on their multitarget therapy. Apoptosis, a programmed cell death, occurs as a normal and controlled process that promotes cell growth and death. Inducing apoptosis is an important strategy to control excessive breast cancer cell proliferation. Accumulating evidence has revealed that natural products become increasingly important in breast cancer treatment by suppressing cell apoptosis. In this study, we reviewed current studies on natural product–induced breast cancer cell apoptosis and summarized the proapoptosis mechanisms including mitochondrial, FasL/Fas, PI3K/AKT, reactive oxygen species, and mitogen-activated protein kinase–mediated pathway. We hope that our review can provide direction in the search for candidate drugs derived from natural products to treat breast cancer by promoting cell apoptosis.

PIK3CA-mutations in breast cancer

PURPOSE

Phosphatidylinositide-3-kinase (PI3K) regulates proliferation and apoptosis; somatic PIK3CA-mutations may activate these processes. Aim of this study was to determine the prevalence of PIK3CA-mutations in a cohort of early stage breast cancer patients and the association to the course of disease.

PATIENTS AND METHODS

From an unselected cohort of 1270 breast cancer patients (PiA, Prognostic Assessment in routine application, NCT01592825) 1123 tumours were tested for the three PIK3CA hotspot-mutations H1047R, E545K, and E542K by qPCR. Primary objectives were the prevalence of somatic PIK3CA-mutations and their association to tumour characteristics. Secondary objective was the association of PIK3CA-mutations to recurrence-free interval (RFI) and overall survival.

RESULTS

PIK3CA-mutation rate was 26.7% (300 of 1123). PIK3CA-mutations were significantly more frequent in steroid hormone-receptor (SHR)-positive HER2-negative (31.4%), and G1 and G2 tumours (32.8%). Overall, we did not observe a significant association of PIK3CA-mutations to RFI. In SHR-positive BCs with PIK3CA-mutations, a strong trend for impaired  RFI was observed (adjusted HR 1.64, 95% CI 0.958-2.807), whilst in SHR-negative BCs PIK3CA-mutations were insignificantly associated with improved RFI (adjusted HR 0.49; 95% CI 0.152-1.597). Of note, we observed a significantly detrimental prognostic impact of PIK3CA-mutations on RFI in SHR-positive, HER2-negative BCs if only aromatase inhibitors were administered as adjuvant therapy (adjusted HR 4.44, 95% CI 1.385-13.920), whilst no impact was observed in tamoxifen treated patients.

CONCLUSION

This cohort study speficies the overall mutation rate of PIK3CA in early breast cancer. The impact of PIK3CA-mutations on RFI and OS was heterogeneous. Our results suggest that estrogen deprivation failes to be active in case of PIK3CA-mutation.

Therapeutic benefits of Salvia species: A focus on cancer and viral infection

Man is increasingly being faced with many health conditions, including viral infection, some of which increases the risk to cancer. These infectious agents contribute to the large number of persons with cancer and the worrisome number that die from the diseases. A good range of drugs are currently in place for treating patients infected with viruses, however, some of the drugs' effectiveness are limited by the emergence of drug-resistant strains of the viruses, as well as adverse effects of the drugs. Similarly, the inability of many anticancer drugs to selectively kill cancer cells while sparing hosts' normal cells limit their use. This warrants more research for newer drugs, especially from chemicals naturally encrypted in plants with anticancer and antiviral activities. In response to infection with cancer-inducing viruses, plants such as Salvia species synthesize and store secondary metabolites to protect themselves and kill these viruses as well as inhibit their ability to induce carcinogenesis. Hence, this review presented a discussion on the potential application of Salvia species in the prevention and management of cancer and viral infection. The study also discusses the cellular mechanisms of action of these herbal products against cancer cells and viruses, where available and provided suggestions on future research directions. The study is believed to spur more research on how to exploit Salvia phytochemicals as candidates for the development of nutraceuticals and drugs for managing cancers and viral infection.