Stem cell therapy: A paradigm shift in breast cancer treatment

Oridonin impedes breast cancer growth by blocking cells in S phase and inhibiting the PI3K/AKT/mTOR signaling pathway

Breast cancer is one of the most common cancers. Oridonin, a traditional Chinese medicine, is believed to inhibit tumor growth, but its particular effects on breast cancer remain unknown. In this study, we examined oridonin's effects on 4T1, MCF-7, and MDAMB-231 cellular activity using CCK8. Scratch assays were used to detect oridonin's effects on cellular migration. Oridonin's effects on the breast cancer cell cycle were studied using flow cytometry, and expression of cell cycle related proteins p53, CDK2, and p21 was detected using Western blot assays. Metabolomics assays were used to detect changes in small molecule metabolites and metabolic pathways in breast cancer cells after treatment with oridonin. Oridonin's effects on breast cancer growth were also studied using xenograft mice. Metabolomics assays were used to detect changes in metabolites and metabolic pathways in xenograft mouse plasma in a control group, model group, and drug administration group. Experimental results showed that oridonin could significantly inhibit breast cancer growth both in vivo and in vitro. Scratch experiments showed that oridonin could inhibit breast cancer cell migration. Oridonin was also able to arrest cells in S phase by affecting several cell cycle-related proteins, including p53, CDK2, and p21. Metabolomic analysis of 4T1 cells identified a total of 33 differential metabolites, including multiple amino acids (such as l-Glutamic acid, l-Asparagine, l-Histidine, l-Valine, and l-Isoleucine). KEGG pathway enrichment analysis showed significant changes in aminoacyl-tRNA biosynthesis, and in multiple amino acid metabolic pathways. Plasma metabolomic analyses of xenograft mice revealed 28 differentially-expressed metabolites between the different animal model groups, including multiple amino acids. KEGG pathway analysis showed significant alterations in multiple amino acid metabolic pathways in oridonin-treated mice. Additionally, changes in the expression of PI3K, AKT and mTOR proteins, as well as in branched amino acids, suggest that oridonin affects the PI3K/AKT/mTOR signaling pathway by inhibiting the biosynthesis of valine, leucine and isoleucine. Taken together, our results suggest that oridonin has strong anti-tumor activity in vitro and in vivo, and has potential as an adjuvant to breast cancer treatment regimens.

Functional biotransformation of phytoestrogens by gut microbiota with impact on cancer treatment

The human gut is a host for trillions of microorganisms, divided into more than 3000 heterogeneous species, which is called the gut microbiota. The gut microbiota composition can be altered by many different endogenous and exogenous factors, especially diet and nutrition. A diet rich in phytoestrogens, a variable group of chemical compounds similar to 17-β-estradiol (E2), the essential female steroid sex hormone is potent to change the composition of gut microbiota. However, the metabolism of phytoestrogens also highly depends on the action of enzymes produced by gut microbiota. Novel studies have shown that phytoestrogens could play an important role in the treatment of different types of cancers, such as breast cancer in women, due to their potential to decrease estrogen levels. This review aims to summarize recent findings about the lively dialogue between phytoestrogens and the gut microbiota and to address their possible future application, especially in treating patients with diagnosed breast cancer. A potential therapeutic approach for the prevention and improving outcomes in breast cancer patients could be based on targeted probiotic supplementation with the use of soy phytoestrogens. A positive effect of probiotics on the outcome and survival of patients with breast cancer has been established. However, more in vivo scientific studies are needed to pave the way for the use of probiotics and phytoestrogens in the clinical practice of breast cancer treatment.

Mechanotransduction through adhesion molecules: Emerging roles in regulating the stem cell niche

Stem cells have been shown to play an important role in regenerative medicine due to their proliferative and differentiation potential. The challenge, however, lies in regulating and controlling their potential for this purpose. Stem cells are regulated by growth factors as well as an array of biochemical and mechanical signals. While the role of biochemical signals and growth factors in regulating stem cell homeostasis is well explored, the role of mechanical signals has only just started to be investigated. Stem cells interact with their niche or to other stem cells via adhesion molecules that eventually transduce mechanical cues to maintain their homeostatic function. Here, we present a comprehensive review on our current understanding of the influence of the forces perceived by cell adhesion molecules on the regulation of stem cells. Additionally, we provide insights on how this deeper understanding of mechanobiology of stem cells has translated toward therapeutics.

Evaluation of CD44+/CD24- and Aldehyde Dehydrogenase Enzyme Markers in Cancer Stem Cells as Prognostic Indicators for Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) has been extensively studied not just for its aggressive behavior but also to understand its complex molecular nature. This type of heterogeneous tumor shows no expression of estrogen receptor (ER) or progesterone receptor (PR) and does not express the HER2 gene, and often these tumors are high grade with distinct histological groups. The basal-like subtype is most commonly related to the TNBC type of neoplasms; it can be further classified according to Lehmann and Burstein expert’s criteria. TNBC is related to breast stem cell markers such as CD44+/CD24- and high levels of enzyme aldehyde dehydrogenase (ALDH), which have been shown to possess stem cell features that are involved in differentiation, vascular invasion, tumorigenesis, and metastatic potential. CD44+/CD24- and high levels of ALDH have significance as markers as well as indicators of poor prognosis in TNBC. The databases used in this review are PMC, PubMed, and Google Scholar.

CRISPR/Cas9-mediated LINC00511 knockout strategies, increased apoptosis of breast cancer cells via suppressing antiapoptotic genes

Background

The growing detection of long noncoding RNAs (lncRNAs) required the application of functional approaches in order to provide absolutely precise, conducive, and reliable processed information along with effective consequences. We utilized genetic knockout (KO) techniques to ablate the Long Intergenic Noncoding RNA 00,511 gene in several humans who suffered from breast cancer cells and at the end we analyzed and examined the results.

Results

The predictive relevance of LINC00511 expression pattern was measured by using a pooled hazard ratio (HR) with a 95% confidence interval (CI). The link among LINC00511 expression profiles and cancer metastasis was measured by using a pooled odds ratio (OR) with a 95% confidence interval. This meta- analysis was composed of fifteen studies which contained a total of 1040 tumor patients. We used three distinct CRISPR/Cas9-mediated knockdown techniques to prevent the LINC00511 lncRNA from being transcribed. RT-PCR was used to measure lncRNA and RNA expression. We used CCK-8, colony formation tests, and the invasion transwell test to measure cell proliferation and invasion. The stemness was measured by using a sphere-formation test. To validate molecular attachment, luciferase reporter assays were performed. The functional impacts of LINC00511 gene deletion in knockdown breast cancer cell lines were confirmed by using RT-qPCR, MTT, and a colony formation test. This meta-analysis was composed of 15 trials which contained a total of 1040 malignant tumors. Greater LINC00511 expression was ascribed to a lower overall survival (HR = 1.93, 95% CI 1.49–2.49, < P 0.001) and to an increased proportion of lymph node metastasis (OR = 3.07, 95% CI 2.23–4.23, P < 0.001) in the meta‐analysis. It was found that the role of LINC00511 was overexpressed in breast cancer samples, and this overexpression was ascribed to a poor prognosis. The gain and loss-of-function tests demonstrated findings such as LINC00511 increased breast cancer cell proliferation, sphere-forming ability, and tumor growth. Additionally, the transcription factor E2F1 binds to the Nanog gene's promoter site to induce transcription. P57, P21, Prkca, MDM4, Map2k6, and FADD gene expression in the treatment group (LINC00511 deletion) was significantly higher than in the control group (P < 0.01). In addition, knockout cells had lower expression of BCL2 and surviving genes than control cells P < 0.001). In each of the two target alleles, the du-HITI approach introduced a reporter and a transcription termination signal. This strategy's donor vector preparation was significantly easier than "CRISPR HDR," and cell selection was likewise much easier than "CRISPR excision." Furthermore, when this approach was used in the initial transfection attempt, single-cell knockouts for both alleles were generated.

Conclusions

The methods employed and described in this work could be extended to the production of LINC00511 knockout cell lines and, in theory, to the deletion of other lncRNAs to study their function.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12575-022-00171-1.

Targeting Breast Cancer Stem Cells Using Naturally Occurring Phytoestrogens

Breast cancer therapies have made significant strides in improving survival for patients over the past decades. However, recurrence and drug resistance continue to challenge long-term recurrence-free and overall survival rates. Mounting evidence supports the cancer stem cell model in which the existence of a small population of breast cancer stem cells (BCSCs) within the tumor enables these cells to evade conventional therapies and repopulate the tumor, giving rise to more aggressive, recurrent tumors. Thus, successful breast cancer therapy would need to target these BCSCs, as well the tumor bulk cells. Since the Women’s Health Initiative study reported an increased risk of breast cancer with the use of conventional hormone replacement therapy in postmenopausal women, many have turned their attention to phytoestrogens as a natural alternative. Phytoestrogens are plant compounds that share structural similarities with human estrogens and can bind to the estrogen receptors to alter the endocrine responses. Recent studies have found that phytoestrogens can also target BCSCs and have the potential to complement conventional therapy eradicating BCSCs. This review summarized the latest findings of different phytoestrogens and their effect on BCSCs, along with their mechanisms of action, including selective estrogen receptor binding and inhibition of molecular pathways used by BCSCs. The latest results of phytoestrogens in clinical trials are also discussed to further evaluate the use of phytoestrogen in the treatment and prevention of breast cancer.

Tumour Stem Cells in Breast Cancer

Tumour stem cells (CSCs) are a self-renewing population that plays important roles in tumour initiation, recurrence, and metastasis. Although the medical literature is extensive, problems with CSC identification and cancer therapy remain. This review provides the main mechanisms of CSC action in breast cancer (BC): CSC markers and signalling pathways, heterogeneity, plasticity, and ecological behaviour. The dynamic heterogeneity of CSCs and the dynamic transitions of CSC⁻ non-CSCs and their significance for metastasis are considered.