Lactobacilli Differentially Modulate mTOR and Wnt/ β-Catenin Pathways in Different Cancer Cell Lines

Microbiome and bladder cancer: the role of probiotics in treatment

Bladder cancer (BCa) remains a significant global health challenge, with increasing interest in the role of the bladder microbiome in its pathogenesis, progression and treatment outcomes. The complex relationship between bladder cancer and the microbiome, as well as the potential impact of probiotics on treatment effectiveness, is currently under investigation. Research suggests that the microbiota may influence BCa recurrence prevention and enhance the efficacy of the Bacillus Calmette-Guérin (BCG) vaccine. Recent studies reveal differences in the bladder microbiome between individuals without bladder cancer and those with the disease. In the healthy bladder, Streptococcus and Lactobacillus are consistently identified as the most prevalent genera. However, in men, the predominant bacterial genera are Staphylococcus, Corynebacterium and Streptococcus, while in women with bladder cancer, Gardnerella and Lactobacillus are dominant. Probiotics, particularly Lactobacillus spp., can exhibit anti-tumor properties by competing with pathogenic strains involved in carcinogenesis or by producing regulatory substances. They regulate cancer signaling, induce apoptosis, inhibit mutagenic activity, downregulate oncogene expression, induce autophagy, inhibit kinases, reactivate tumor suppressors and prevent metastasis. These mechanisms have shown promising results in both preclinical and some clinical studies.

The effect of psychoactive bacteria, Bifidobacterium longum Rosell®-175 and Lactobacillus rhamnosus JB-1, on brain proteome profiles in mice

RATIONALE

The gut microbiota may play an important role in the development and functioning of the mammalian central nervous system. The assumption of the experiment was to prove that the use of probiotic bacterial strains in the diet of mice modifies the expression of brain proteins involved in metabolic and immunological processes.

OBJECTIVES AND RESULTS

Albino Swiss mice were administered with Bifidobacterium longum Rosell®-175 or Lactobacillus rhamnosus JB-1 every 24 h for 28 days. Protein maps were prepared from hippocampal homogenates of euthanized mice. Selected proteins that were statistically significant were purified and concentrated and identified using MALDI-TOF mass spectrometry. Among the analysed samples, 13 proteins were identified. The mean volumes of calcyon, secreted frizzled-associated protein 3, and catalase in the hippocampus of mice from both experimental groups were statistically significantly higher than in the control group. In mice supplemented with Lactobacillus rhamnosus JB-1, a lower mean volume of fragrance binding protein 2, shadow of prion protein, and glycine receptor α4 subunit was observed compared to the control.

CONCLUSION

The psychobiotics Bifidobacterium longum Rosell®-175 and Lactobacillus rhamnosus JB-1enhances expression of proteins involved in the activation and maturation of nerve cells, as well as myelination and homeostatic regulation of neurogenesis in mice. The tested psychobiotics cause a decrease in the expression of proteins associated with CNS development and in synaptic transmission, thereby reducing the capacity for communication between nerve cells. The results of the study indicate that psychobiotic bacteria can be used in auxiliary treatment of neurological disorders.

PYGO2 increases proliferation and migration capacities through critical signaling pathways in esophageal squamous cell carcinoma

Esophageal cancer, an increasingly prevalent malignancy, is a major concern for global health. The development of esophageal squamous cell carcinoma (ESCC) involves various genetic abnormalities that affect key cell signaling pathways, including Wnt, Hh, Apoptosis, MAPK, EGFR, AKT, Notch, and EMT. Additionally, this malignancy involves some changes in the expression of long noncoding RNAs (LncRNAs). The present study examines the relationship between PYGO2 gene expression and the activity of cell signaling pathways in KYSE-30 and YM-1ESCC cell lines. To this end, several cellular and molecular tests were performed, including cell migration, cell cycle, and apoptosis. Also, expression levels of CD133 and CD44 markers, real-time PCR, and western blot were analyzed after inducing PYGO2 protein expression in the cells. Overexpression of the PYGO2 protein resulted in the upregulation of Wnt pathway-related genes, leading to enhanced cell migration and proliferation and reduced apoptosis in both cell lines. Furthermore, PYGO2 gene expression induction analysis showed the correlation of several involved genes in Wnt, Hh, Apoptosis, MAPK, EGFR, AKT, and EMT pathways with various LncRNAs.

Potential effects of gut microbiota on host cancers: focus on immunity, DNA damage, cellular pathways, and anticancer therapy

The symbiotic bacteria that live in the human gut and the metabolites they produce have long influenced local and systemic physiological and pathological processes of the host. The gut microbiota are increasingly being recognized for its impact on a range of human diseases, including cancer, it may play a key role in the occurrence, progression, treatment, and prognosis of many types of cancer. Understanding the functional role of the gut microbiota in cancer is crucial for the development of the era of personalized medicine. Here, we review recent advances in research and summarize the important associations and clear experimental evidence for the role of the gut microbiota in a variety of human cancers, focus on the application and possible challenges associated with the gut microbiota in antitumor therapy. In conclusion, our research demonstrated the multifaceted mechanisms of gut microbiota affecting human cancer and provides directions and ideas for future clinical research.

Bacillus subtilis supernatant improves the efficacy of radiation therapy in rat intestinal epithelial cells by upregulation of bax and caspase-3 genes

BACKGROUND

Colorectal Cancer (CC) is among the most prevalent cancers in elderly persons. Radiotherapy is usually prescribed as CC develops, however, radiation beams indiscriminately affect normal cells. Previous studies nominated that probiotics and their metabolites can be used to minimize the side effects of radiotherapy. Hereby, the aim of this study was to investigate the probable correlation between cell-free supernatant of Bacillus subtilis and radiation response in normal and cancerous cell lines.

METHODS AND RESULTS

IEC-18 and SW-48 cells were treated with different concentrations of B. subtilis supernatant. To evaluate the effect of probiotic treatments under radiation and the normal situation, the cytotoxicity of the treatments was measured using the MTT method. The cell cycle status was analyzed by flow cytometry. The expression levels of Bax, Bcl-2, and Caspase 3 genes were also determined by real-time (RT) PCR. B. subtilis supernatant increased the viability of normal cells under radiation treatment, although this effect was not significant. 40% v/v of this mixture could amplify the lethal effect of radiation and decreased the viability of cancer cells. SW-48 cells that received 40% v/v of the supernatant had a significantly higher rate of apoptosis. Probiotic supernatant effectively induced the expression of proapoptotic Bax and Caspase 3 genes.

CONCLUSION

Presented results confirmed that the supernatant of B. subtilis can be supposed as a clue to improve the efficacy of radiation therapy in CC patients as it increased the sensitivity of cancerous cells and protected normal epithelial cells from detrimental effects of radiation.

Carbon dots labeled Lactiplantibacillus plantarum: a fluorescent multifunctional biocarrier for anticancer drug delivery

A carbon dots (CDs)-biolabeled heat-inactivated Lactiplantibacillus plantarum (HILP) hybrid was investigated as a multifunctional probiotic drug carrier with bioimaging properties using prodigiosin (PG) as anticancer agent. HILP, CDs and PG were prepared and characterized using standard methods. CDs-labeled HILP (CDs/HILP) and PG loaded CDs/HILP were characterized by transmission electron microscopy (TEM), laser scanning confocal microscopy (LSCM) and for entrapment efficiency (EE%) of CDs and PG, respectively. PG-CDs/HILP was examined for stability and PG release. the anticancer activity of PG-CDs/HILP was assessed using different methods. CDs imparted green fluorescence to HILP cells and induced their aggregation. HILP internalized CDs via membrane proteins, forming a biostructure with retained fluorescence in PBS for 3 months at 4°C. Loading PG into CDs/HILP generated a stable green/red bicolor fluorescent combination permitting tracking of both drug carrier and cargo. Cytotoxicity assay using Caco-2 and A549 cells revealed enhanced PG activity by CDs/HILP. LCSM imaging of PG-CDs/HILP-treated Caco-2 cells demonstrated improved cytoplasmic and nuclear distribution of PG and nuclear delivery of CDs. CDs/HILP promoted PG-induced late apoptosis of Caco-2 cells and reduced their migratory ability as affirmed by flow cytometry and scratch assay, respectively. Molecular docking indicated PG interaction with mitogenic molecules involved in cell proliferation and growth regulation. Thus, CDs/HILP offers great promise as an innovative multifunctional nanobiotechnological biocarrier for anticancer drug delivery. This hybrid delivery vehicle merges the physiological activity, cytocompatibility, biotargetability and sustainability of probiotics and the bioimaging and therapeutic potential of CDs.

Research Trend and Detailed Insights into the Molecular Mechanisms of Food Bioactive Compounds against Cancer: A Comprehensive Review with Special Emphasis on Probiotics

In an attempt to find a potential cure for cancer, scientists have been probing the efficacy of the food we eat and its bioactive components. Over the decades, there has been an exponentially increasing trend of research correlating food and cancer. This review explains the molecular mechanisms by which bioactive food components exhibit anticancer effects in several cancer models. These bioactive compounds are mainly plant based or microbiome based. While plants remain the primary source of these phytochemicals, little is known about probiotics, i.e., microbiome sources, and their relationships with cancer. Thus, the molecular mechanisms underlying the anticancer effect of probiotics are discussed in this review. The principal mode of cell death for most food bioactives is found to be apoptosis. Principal oncogenic signaling axes such as Akt/PI3K, JAK/STAT, and NF-κB seem to be modulated due to these bioactives along with certain novel targets that provide a platform for further oncogenic research. It has been observed that probiotics have an immunomodulatory effect leading to their chemopreventive actions. Various foods exhibit better efficacy as complete extracts than their individual phytochemicals, indicating an orchestrated effect of the food components. Combining bioactive agents with available chemotherapies helps synergize the anticancer action of both to overcome drug resistance. Novel techniques to deliver bioactive agents enhance their therapeutic response. Such combinations and novel approaches are also discussed in this review. Notably, most of the food components that have been studied for cancer have shown their efficacy in vivo. This bolsters the claims of these studies and, thus, provides us with hope of discovering anticancer agents in the food that we eat.

Impact of intestinal dysbiosis on breast cancer metastasis and progression

Breast cancer has a high mortality rate among malignant tumors, with metastases identified as the main cause of the high mortality. Dysbiosis of the gut microbiota has become a key factor in the development, treatment, and prognosis of breast cancer. The many microorganisms that make up the gut flora have a symbiotic relationship with their host and, through the regulation of host immune responses and metabolic pathways, are involved in important physiologic activities in the human body, posing a significant risk to health. In this review, we build on the interactions between breast tissue (including tumor tissue, tissue adjacent to the tumor, and samples from healthy women) and the microbiota, then explore factors associated with metastatic breast cancer and dysbiosis of the gut flora from multiple perspectives, including enterotoxigenic Bacteroides fragilis, antibiotic use, changes in gut microbial metabolites, changes in the balance of the probiotic environment and diet. These factors highlight the existence of a complex relationship between host-breast cancer progression-gut flora. Suggesting that gut flora dysbiosis may be a host-intrinsic factor affecting breast cancer metastasis and progression not only informs our understanding of the role of microbiota dysbiosis in breast cancer development and metastasis, but also the importance of balancing gut flora dysbiosis and clinical practice.

An Update on the Effectiveness of Probiotics in the Prevention and Treatment of Cancer

Probiotics are living microbes that play a significant role in protecting the host in various ways. Gut microbiota is one of the key players in maintaining homeostasis. Cancer is considered one of the most significant causes of death worldwide. Although cancer treatment has received much attention in recent years, the number of people suffering from neoplastic syndrome continues to increase. Despite notable improvements in the field of cancer therapy, tackling cancer has been challenging due to the multiple properties of cancer cells and their ability to evade the immune system. Probiotics alter the immunological and cellular responses by enhancing the epithelial barrier and stimulating the production of anti-inflammatory, antioxidant, and anticarcinogenic compounds, thereby reducing cancer burden and growth. The present review focuses on the various mechanisms underlying the role of probiotics in the prevention and treatment of cancer.

Genome Editing with Cas9 in Lactobacilli

The bacterial genus Lactobacillus comprises a vast range of strains with varying metabolic and probiotic traits, with genome editing representing an essential tool to probe genotype-phenotype relationships and enhance their beneficial properties. Currently, one of the most effective means of genome editing in bacteria couples low-efficiency recombineering with high-efficiency counterselection by nucleases from CRISPR-Cas systems. In lactobacilli, several CRISPR-based genome editing methods exist that have shown varying success in different strains. Here, we detail a fast and simple approach using two shuttle vectors encoding a recombineering template as well as the Streptococcus pyogenes Cas9, a trans-activating RNA, and a CRISPR array. We provide a step-by-step procedure for cloning the shuttle vectors, sequentially transforming the vectors into lactobacilli, screening for the desired edit, and finally clearing the shuttle vectors from the mutant strain. As CRISPR-based genome editing in bacteria can fail for various reasons, we also lay out instructions for probing mechanisms of escape. Finally, we include practical notes along the way to facilitate each stage of genome editing, and we illustrate the technique using a representative edit in a strain of Lactobacillus plantarum. Overall, this method should serve as a complete guide to performing genome editing in lactobacilli.

Biotechnological Applications of Probiotics: A Multifarious Weapon to Disease and Metabolic Abnormality

Consumption of live microorganisms "Probiotics" for health benefits and well-being is increasing worldwide. Their use as a therapeutic approach to confer health benefits has fascinated humans for centuries; however, its conceptuality gradually evolved with methodological advancement, thereby improving our understanding of probiotics-host interaction. However, the emerging concern regarding safety aspects of live microbial is enhancing the interest in non-viable or microbial cell extracts, as they could reduce the risks of microbial translocation and infection. Due to technical limitations in the production and formulation of traditionally used probiotics, the scientific community has been focusing on discovering new microbes to be used as probiotics. In many scientific studies, probiotics have been shown as potential tools to treat metabolic disorders such as obesity, type-2 diabetes, non-alcoholic fatty liver disease, digestive disorders (e.g., acute and antibiotic-associated diarrhea), and allergic disorders (e.g., eczema) in infants. However, the mechanistic insight of strain-specific probiotic action is still unknown. In the present review, we analyzed the scientific state-of-the-art regarding the mechanisms of probiotic action, its physiological and immuno-modulation on the host, and new direction regarding the development of next-generation probiotics. We discuss the use of recently discovered genetic tools and their applications for engineering the probiotic bacteria for various applications including food, biomedical applications, and other health benefits. Finally, the review addresses the future development of biological techniques in combination with clinical and preclinical studies to explain the molecular mechanism of action, and discover an ideal multifunctional probiotic bacterium.

Cell cycle arrest and anti-cancer potential of probiotic Lactobacillus rhamnosus against HT-29 cancer cells

Introduction: Nowadays, probiotic bacteria have been considered as a factor in the prevention and treatment of cancer, especially by induction of apoptosis. This study aimed to evaluate the cytotoxic, anti-proliferative, and apoptotic effects of the supernatant of probiotic Lactobacillus rhamnosus on HT-29 cell line.

Methods : Molecular identification of probiotic L. rhamnosus was carried out using specific primers of 16S rRNA gene and sequencing. HT-29 cells were treated with different concentrations of bacterial supernatants at 24, 48, and 72 hours. MTT assay, Annexin V-FITC, real-time PCR, cell cycle analysis, and DAPI staining tests were conducted to evaluate the induction of apoptosis. The level of cyclin D1 protein was measured by immunocytochemistry method.

Results: The supernatant of L. rhamnosus inhibited the growth of HT-29 cancer cells in a dose- and time-dependent manner. The results of flow cytometry confirmed apoptotic cell death. Probiotic bacterial supernatant caused up-regulation of pro-apoptotic genes including caspase-3, caspase-9, and Bax. In addition, they resulted in down-regulation of Bcl2 and a decrease in expression levels of cyclin D1, cyclin E, and ERBB2 genes. Cancer cells were arrested in the G0/G1 phase of the cell cycle. The results of immunocytochemistry showed significant down-regulation of cyclin D1 protein during the 48 hours treatment with bacterial supernatant compared to the untreated cells.

Conclusion: The supernatant of probiotic L. rhamnosus has a great potential to inhibit the proliferation of HT-29 cells and the induction of apoptosis. L. rhamnosus might be used as a biological anti-cancer factor in the prevention and treatment of colon cancer.

Lactobacillus fermentum and Lactobacillus crispatus Do Not Have Cytotoxic Effects on HN5 Oral Squamous Cell Carcinoma Cell Line

Background

The oral environment has a very complex normal flora and a wide variety of bacteria including lactobacilli. Studies have shown oral microbial flora has important influence in the development of oral cancer. Squamous cell carcinomas account for more than 90% of cancers in oral cavity. Lactobacilli are known as one of the newest methods for the prevention and treatment of cancers. Previous studies on the effects of probiotics on oral cancer cells are very limited, and only two species of Lactobacillus which are not present in the normal oral microflora have been studied. Due to the unknown effects of lactobacilli on oral cancer, this study aimed to investigate the effect of two species of lactobacilli of oral cavity on oral cancer cells.

Methods and Materials

The effects of the supernatant of two lactobacilli, namely, fermentum and crispatus were studied on HN5-cancer cells. The MTT method was used to study the effects of lactobacilli on inhibition of cancer cell growth.

Results

The results showed that these lactobacilli do not prevent the progression of oral cancer cells. Moreover, the results showed that the acidic medium had the most effect on reducing the growth of oral cancer cells.

Conclusion

Due to the different effects of lactobacilli on various cancer types, the effects of two Lactobacillus crispatus and Lactobacillus fermentum on other oral cancer cell lines may be different from what has been reported in this study.

Cell-Free Culture Supernatant of Probiotic Lactobacillus fermentum Protects Against H2O2-Induced Premature Senescence by Suppressing ROS-Akt-mTOR Axis in Murine Preadipocytes

Information regarding cellular anti-senescence attributes of probiotic bacteria vis-à-vis modulation of senescence-associated secretory phenotype (SASP) and mTOR signaling is very limited. The present study assessed anti-senescence potential of secretory metabolites of probiotic Lactobacillus fermentum (Lact. fermentum) using H₂O₂-induced model of senescence in 3T3-L1 preadipocytes. Application of H₂O₂-induced cellular senescence characterized by increased cell size and SA-β-gal activity, activation of SASP and reactive oxygen species (ROS), DNA damage response and induction of cell cycle inhibitors (p53/p21^WAF1/p16^INK4a). Further, a robust stimulation of the PI3K/Akt/mTOR pathway and AMPK signaling was also observed in H₂O₂-treated cells. However, exposure of cells to cell-free supernatant of Lact. fermentum significantly attenuated phosphorylation of PI3K/Akt/mTOR pathway and alleviated senescence markers p53, p21^WAF1, SA-β-gal, p38MAPK, iNOS, cox-2, ROS, NF-κB, and DNA damage response. These results provide evidence that secretory metabolites of Lact. fermentum can mitigate the development as well as severity of stress-induced senescence thereby indicating its utility for use as anti-aging or age-delaying agent.

The germ-free mice monocolonization with Bacteroides fragilis improves azoxymethane/dextran sulfate sodium induced colitis-associated colorectal cancer

Objective: Inflammatory bowel disease (IBD) is generally considered as a major risk factor in the progression of colitis-associated colorectal cancer (CAC). Previous studies have indicated that the composition of gut microflora may be involved in CAC induction and progress. Bacteroides fragilis (BF) is a Gram-negative anaerobe belonging to colonic symbiotic bacteria of the host. This study was aimed to investigate the protective role of BF in a colorectal cancer (CRC) model induced by azoxymethane (AOM) and dextran sulfate sodium (DSS) in germ-free (GF) mice. Materials and methods: Total 22 GF mice were divided into two groups: GF and BF group. Half of the GF mice were colonized with BF for 28 days before CRC induction by AOM/DSS. Results: BF colonization increased animal survival (100%). Cecum weight and cecum/body weight ratio significantly decreased in BF/AOM/DSS group. Interestingly, there was a significant decrease in tumor number and tumor incidence in the BF/AOM/DSS group as compared to the GF/AOM/DSS group. The adenocarcinoma/adenoma incidence and histologic score were also decreased in the BF/AOM/DSS group. In addition, immunohistochemistry staining found decreased numbers of cell proliferation (PCNA) and inflammatory cell (granulocytes) infiltration in the colon mucosa of the BF group. The β-catenin staining in the BF/AOM/DSS group had fewer and weaker positive signal expressions. Taking together, the BF colonization significantly ameliorated AOM/DSS-induced CRC by suppressing the activity of cell proliferation-related molecules and reducing the number of inflammatory cells. Conclusions: Symbiotic BF may play a pivotal role in maintaining the gastrointestinal immunophysiologic balance and regulating anti-tumorigenesis responses.

Gut Microbiota and Cancer: From Pathogenesis to Therapy

Cancer is a multifactorial pathology and it represents the second leading cause of death worldwide. In the recent years, numerous studies highlighted the dual role of the gut microbiota in preserving host’s health. Gut resident bacteria are able to produce a number of metabolites and bioproducts necessary to protect host’s and gut’s homeostasis. Conversely, several microbiota subpopulations may expand during pathological dysbiosis and therefore produce high levels of toxins capable, in turn, to trigger both inflammation and tumorigenesis. Importantly, gut microbiota can interact with the host either modulating directly the gut epithelium or the immune system. Numerous gut populating bacteria, called probiotics, have been identified as protective against the genesis of tumors. Given their capability of preserving gut homeostasis, probiotics are currently tested to help to fight dysbiosis in cancer patients subjected to chemotherapy and radiotherapy. Most recently, three independent studies show that specific gut resident species may potentiate the positive outcome of anti-cancer immunotherapy. The highly significant studies, uncovering the tight association between gut microbiota and tumorigenesis, as well as gut microbiota and anti-cancer therapy, are here described. The role of the Lactobacillus rhamnosus GG (LGG), as the most studied probiotic model in cancer, is also reported. Overall, according to the findings here summarized, novel strategies integrating probiotics, such as LGG, with conventional anti-cancer therapies are strongly encouraged.

In Vitro Transcriptome Response to a Mixture of Lactobacilli Strains in Intestinal Porcine Epithelial Cell Line

Background: Food and feed supplements containing microorganisms with probiotic potential are of increasing interest due to their healthy promoting effect on human and animals. Their mechanism of action is still unknown. Using a microarray approach, the aim of this study was to investigate the differences in genome-wide gene expression induced by a mixture of three Lactobacillus strains (L. rhamnosus, L. plantarum, and L. paracasei) in intestinal porcine epithelial cells (IPEC-1) and to identify the genes and pathways involved in intestinal barrier functions. Methods: Undifferentiated IPEC-1 cells seeded at a density of 2.0 × 10⁵/mL in 24-wells culture plates were cultivated at 37 °C and 5% CO₂ until they reached confluence (2–3 days). Confluent cells monolayer were then cultivated with 1 mL of fresh lactobacilli (LB) mixture suspension prepared for a concentration of approximately 3.3 × 10⁷ CFU/mL for each strain (1 × 10⁸ CFU/mL in total) for 3 h and analyzed by microarray using Gene Spring GX v.11.5. Results: The functional analysis showed that 1811 of the genes modulated by LB treatment are involved in signaling (95% up-regulation, 121 genes with a fold change higher than 10). The most enhanced expression was registered for AXIN2 (axis inhibition protein 2-AXIN2) gene (13.93 Fc, p = 0.043), a negative regulator of β-catenin with a key role in human cancer. LB affected the cellular proliferation by increasing 10 times (Fc) the NF1 gene encoding for the neurofibromin protein, a tumor suppressor that prevent cells from uncontrolled proliferation. The induction of genes like serpin peptidase inhibitor, clade A member 3 (SERPINA 3), interleukin-20 (IL-20), oncostatin M(OSM), granulocyte-macrophage colony-stimulating factor (GM-CSF), and the suppression of chemokine (C-X-C motif) ligand 2/macrophage inflammatory protein 2-alpha (CXCL-2/MIP-2), regulator of G-protein signaling 2 (RGS2), and of pro-inflammatory interleukin-18 (IL-18) genes highlights the protective role of lactobacilli in epithelial barrier function against inflammation and in the activation of immune response. Conclusion: Gene overexpression was the predominant effect produced by lactobacilli treatment in IPEC-1 cells, genes related to signaling pathways being the most affected. The protective role of lactobacilli in epithelial barrier function against inflammation and in the activation of immune response was also noticed.

Long Non Coding RNA Expression Intersecting Cancer and Spermatogenesis: A Systematic Review

Background: Numerous similarities have been noted between gametogenic and tumorigenic programs in features such as global hypomethylation, immune evasion, immortalization, meiosis induction, and migration. In addition, aberrant expression of testis specific genes has been detected in various cancers which has led to categorization of these genes as “cancer-testis genes”. Most of the examples identified in this category are protein encoding. However, recent studies have revealed that non-coding RNAs, including long non coding RNAs (lncRNAs), may have essential regulatory roles in telomere biology, chromatin dynamics, modulation of gene expression and genome structural organization. All of these functions are implicated in both gametogenic and tumorigenic programs. Methods: In the present study, we conducted a computerized search of the MEDLINE/PUBMED and Embase databases with the key words lncRNA, gametogenesis, testis and cancer. Results: We found a number of lncRNAs with essential roles and notable expression in both gametogenic and cancer tissues. Conclusions: Comparison between cancer tissues and gametogenic tissues has shown that numerous lncRNAs are expressed in both, playing similar roles in processes modulated by signaling pathways such as Wnt/β-catenin and PI3K/AKT/mTOR. Evaluation of expression patterns and functions of these genes should pave the way to discovery of biomarkers for early detection, prognostic assessment and evaluation of therapeutic responses in cancers.

The Role of Probiotics in Cancer Treatment: Emphasis on their In Vivo and In Vitro Anti-metastatic Effects

Probiotics are defined as live bacteria and yeasts that exert beneficial effects for health. Among their various effects, anti-cancer properties have been highlighted in recent years. Such effects include suppression of the growth of microbiota implicated in the production of mutagens and carcinogens, alteration in carcinogen metabolism and protection of DNA from oxidative damage as well as regulation of immune system. We performed a computerized search of the MEDLINE/PUBMED databases with key words: cancer, probiotics, lactobacilli, metastasis and invasion. Cell line studies as well as animal models and human studies have shown the therapeutic effects of probiotics in reduction of invasion and metastasis in cancer cells. These results support the beneficial effects of probiotics both in vitro and in vivo. However, pre-clinical or clinical studies are not enough to decide about their application.

Expression Study and Clinical Correlations of MYC and CCAT2 in Breast Cancer Patients

Background:

Colon cancer-associated transcript 2 (CCAT2) is a newly recognized lncRNA transcribed from the 8q24 genomic region. It functions as an oncogene in various types of cancers including breast cancer, in which it affects Wnt/β-catenin pathway. Previous studies have shown a putative interaction between this lncRNA and MYC proto-oncogene.

Methods:

In the current study, we evaluated the expression of CCAT2 in breast cancer tissues with regards to the expression of its target MYC. In addition, we assessed the relationship between CCAT2 and MYC expression levels in tumor tissues and the clinical prognostic characteristics of breast cancer patients.

Results:

MYC expression levels were significantly up-regulated in tumor tissues compared with adjacent non-cancerous tissues (ANCTs), while such analysis showed no statistically significant difference between these two tissue types in CCAT2 expression. Starkly increased CCAT2 gene expression levels were found in 12/48 (25%) of cancer tissue samples compared with their corresponding ANCTs. Furthermore, significant inverse correlations were found between CCAT2 expression and stage, as well as lymph node involvement. Besides, a significant inverse correlation was found between the relative MYC expression in tumor tissues compared with their corresponding ANCTs and disease stage.

Conclusions:

These results highlight the significance of MYC and CCAT2 expressions in the early stages of breast cancer development and suggest a potentially significant role for CCAT2 in a subset of breast cancer patients, which could be applied as a potential therapeutic target in these patients.