Interaction with the GDF8/11 pathway reveals treatment options for adenocarcinoma of the breast

Tissue Expression of Growth Differentiation Factor 11 in Patients with Breast Cancer

Protein growth differentiation factor 11 (GDF11) plays crucial roles in cellular processes, including differentiation and development; however, its clinical relevance in breast cancer patients is poorly understood. We enrolled 68 breast cancer patients who underwent surgery at our hospital and assessed the expression of GDF11 in tumorous, ductal carcinoma in situ (DCIS), and non-tumorous tissues using immunohistochemical staining, with interpretation based on histochemical scoring (H-score). Our results indicated higher GDF11 expressions in DCIS and normal tissues compared to tumorous tissues. In addition, the GDF11 H-score was lower in the patients with a tumor size ≥ 2 cm, pathologic T3 + T4 stages, AJCC III-IV stages, Ki67 ≥ 14% status, HER2-negative, and specific molecular tumor subtypes. Notably, the patients with triple-negative breast cancer exhibited a loss of GDF11 expression. Spearman correlation analysis revealed associations between GDF11 expression and various clinicopathological characteristics, including tumor size, stage, Ki67, and molecular subtypes. Furthermore, GDF11 expression was positively correlated with mean corpuscular hemoglobin concentration and negatively correlated with neutrophil count, as well as standard deviation and coefficient of variation of red cell distribution width. These findings suggest that a decreased GDF11 expression may play a role in breast cancer pathogenesis.

GDF11 as a friend or an enemy in the cancer biology?

The Growth and Differential Factor 11 (GDF11) is a recently discovered representative of Transforming Growth Factor β superfamily. The highest expression of GDF11 is detected in the nervous system, bladder, seminal vesicles and muscles whereas the lowest in the testis, liver or breast. GDF11 role in physiology is still not clear. GDF11 is a crucial factor in embryogenesis, cell cycle control and apoptosis, inasmuch it mainly targets cell retain stemness features, managing to the cell differentiation and the maturation. GDF11 is entangled in lipid metabolism, inflammatory processes and aging. GDF11 is strongly related to carcinogenesis and its expression in tumors is intruded. GDF11 can promote cancer growth in the colon or inhibit the cell proliferation in breast cancer. The aberrated expression is probably allied with the impaired maturation. In this article we summarized an impact of GDF11 on the tumor cells and review the all attitudes connecting GDF11 with carcinogenesis.

Integrative characterisation of secreted factors involved in intercellular communication between prostate epithelial or cancer cells and fibroblasts

Reciprocal interactions between prostate cancer cells and carcinoma-associated fibroblasts (CAFs) mediate cancer development and progression; however, our understanding of the signalling pathways mediating these cellular interactions remains incomplete. To address this, we defined secretome changes upon co-culture of prostate epithelial or cancer cells with fibroblasts that mimic bi-directional communication in tumours. Using antibody arrays, we profiled conditioned media from mono- and co-cultures of prostate fibroblasts, epithelial and cancer cells, identifying secreted proteins that are upregulated in co-culture compared to mono-culture. Six of these (CXCL10, CXCL16, CXCL6, FST, PDGFAA, IL-17B) were functionally screened by siRNA knockdown in prostate cancer cell/fibroblast co-cultures, revealing a key role for follistatin (FST), a secreted glycoprotein that binds and bioneutralises specific members of the TGF-β superfamily, including activin A. Expression of FST by both cell types was required for the fibroblasts to enhance prostate cancer cell proliferation and migration, whereas FST knockdown in co-culture grafts decreased tumour growth in mouse xenografts. This study highlights the complexity of prostate cancer cell-fibroblast communication, demonstrates that co-culture secretomes cannot be predicted from individual cultures, and identifies FST as a tumour-microenvironment-derived secreted factor that represents a candidate therapeutic target.

Deficiency of myostatin protects skeletal muscle cells from ischemia reperfusion injury

Ischemia reperfusion (IR) injury plays a pivotal role in many diseases and leads to collateral damage during surgical interventions. While most studies focus on alleviating its severity in the context of brain, liver, kidney, and cardiac tissue, research as regards to skeletal muscle has not been conducted to the same extent. In the past, myostatin (MSTN), primarily known for supressing muscle growth, has been implicated in inflammatory circuits, and research provided promising results for cardiac IR injury mitigation by inhibiting MSTN cell surface receptor ACVR2B. This generated the question if interrupting MSTN signaling could temper IR injury in skeletal muscle. Examining human specimens from free myocutaneous flap transfer demonstrated increased MSTN signaling and tissue damage in terms of apoptotic activity, cell death, tissue edema, and lipid peroxidation. In subsequent in vivo Mstn^Ln/Ln IR injury models, we identified potential mechanisms linking MSTN deficiency to protective effects, among others, inhibition of p38 MAPK signaling and SERCA2a modulation. Furthermore, transcriptional profiling revealed a putative involvement of NK cells. Collectively, this work establishes a protective role of MSTN deficiency in skeletal muscle IR injury.

Down-regulated FST expression is involved in the poor prognosis of triple-negative breast cancer

Background

Triple-negative breast cancer (TNBC) is more commonly associated with young patients, featuring high histological grade, visceral metastasis, and distant recurrence. Follistatin (FST) is a secreted extracellular regulatory protein that antagonizes TGF-β superfamily such as activin and TGF-β related superfamily such as bone morphogenetic protein (BMP). The implication of FST in the proliferation, angiogenesis, and metastasis of solid tumors documents good or poor outcome of patients with BC. However, the role of FST in TNBC remains unclear.

Methods

Data of 935 patients with breast cancer (BC) were extracted from TCGA. Case–control study, Kaplan–Meier, uni-multivariate COX, and ROC curve were utilized to investigate the relationship between FST expression and the clinical characteristics and prognosis of BC. Functional studies were used to analyze the effect of FST expression on proliferation, apoptosis, migration, and invasion of TNBC cell lines. Bioinformatic methods such as volcanoplot, GO annd KEGG enrichment, and protein–protein interactions (PPI) analyses were conducted to further confirm the different roles of FST in the apoptotic pathways among mesenchymal and mesenchymal stem-like cells of TNBC.

Results

Data from TCGA showed that low FST expression correlated with poor prognosis (for univariate analysis, HR = 0.47, 95% CI: 0.27–0.82, p = 0.008; for multivariate analysis, HR = 0.40, 95% CI: 0.21–0.75, p = 0.004). Low FST expression provided high predicted value of poor prognosis in TNBC amongst BCs. FST knockdown promoted the proliferation, migration and invasion of BT549 and HS578T cell lines. FST inhibited the apoptosis of mesenchymal cells by targeting BMP7.

Conclusions

Low FST expression is associated with poor prognosis of patients with TNBC. FST expressions exhibit the anisotropic roles of apoptosis between mesenchymal and mesenchymal stem-like cells but promote the proliferation, migration, invasion in both of two subtypes of TNBC in vitro. FST may be a subtype-heterogeneous biomarker for monitoring the progress of TNBC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01977-x.

Collagen I Fibrous Substrates Modulate the Proliferation and Secretome of Estrogen Receptor-Positive Breast Tumor Cells in a Hormone-Restricted Microenvironment

The fibril orientation of type I collagen has been shown to contribute to tumor invasion and metabolic changes. Yet, there is limited information about its impact on tumor cells' behavior in a restrictive growth environment. Restrictive growth environments are generated by the inhibition of a proliferation stimulus during therapy or as an inflammatory response to suppress tumor expansion. In this study, the impact of a type I collagen matrix orientation and fibrous architecture on cell proliferation and response to estrogen receptor (ER) therapy were examined using estrogen-dependent breast tumor cells (MCF-7 and T-47D) cultured in a hormone-restricted environment. The use of hormone-free culture media, as well as pharmacological inhibitors of ER, Tamoxifen, and Fulvestrant, were investigated as hormone restrictive conditions. Examination of cultures at 72 h showed that tumor cell proliferation was significantly stimulated (1.8-fold) in the absence of hormones on collagen fibrous substrates, but not on polycaprolactone fibrous substrates of equivalent orientation. ER inhibitors did not suppress cell proliferation on collagen fibrous substrates. The examination of reporter cells for ER signaling showed a lack of activity, thus confirming a shift toward an ER-independent proliferation mechanism. Examination of two selective inhibitors of α2β1 and α1β1 integrins showed that cell proliferation is suppressed in the presence of the α2β1 integrin inhibitor only, thereby indicating that the observed changes in tumor cell behavior are caused by a combination of integrin signaling and/or an intrinsic structural motif that is uniquely present in the collagen fibrils. Adjacent coculture studies on collagen substrates showed that tumor cells on collagen can stimulate the proliferation of cells on tissue culture plastic through soluble factors. The magnitude of this effect correlated with the increased surface anisotropy of the substrate. This sensing in fibril orientation was further supported by a differential expression pattern of secreted proteins that were identified on random and aligned orientation substrates. Overall, this study shows a new role for electrospun collagen I fibrous substrates by supporting a shift toward an ER-independent tumor cell proliferation mechanism in ER+ breast tumor cells.

Regulatory aspects of myogenic factors GDF-8 and Follistatin on the intake of combined oral contraceptives

Combined oral contraceptives are one of the most prescribed drugs in the western world. While there is little evidence regarding effects of estrogen or gestagens on muscle metabolism, androgens are well-known for their anabolic characteristics. In this study, we seeked to investigate potential correlations of the myokines GDF-8, IGF-1 and Follistatin with female sexual hormones and likewise possible interactions with combined oral contraceptives (Dienogest and Ethyl Estradiol) intake. We obtained serum samples of young healthy women to measure hormone correlations. Furthermore, we simulated combined oral contraceptive blood circulating hormone concentrations to identify myogenic effects on HSkM in vitro. GDF-8, IGF-1 and Follistatin showed concentration correlations (p = .005) in overall patients' serum, while Follistatin as a promyogenic protein additionally showed a positive correlation with testosterone and estradiol (p < .05). Lower GDF-8 levels were also linked to a higher BMI (p = .009). Upon combined oral contraceptives (COC) intake, patients showed decreased GDF-8 (p = .006) but increased Follistatin (p = .0001) concentrations compared to patients without COC intake. In vitro, addition of Ethyl Estradiol and Dienogest to HSkM cells revealed a pro-myogenic, proliferative, chemosensitized pattern. Our data support a pro-myogenic effect of combined oral contraceptives.

Effects of Steady Low-Intensity Exercise on High-Fat Diet Stimulated Breast Cancer Progression Via the Alteration of Macrophage Polarization

Physical inactivity and high-fat diet, especially high saturated fat containing diet are established risk factors for breast cancer that are amenable to intervention. High-fat diet has been shown to induce tumor growth and metastasis by alteration of inflammation but steady exercise has anti-tumorigenic effects. However, the mechanisms underlying the effects of physical activity on high-fat diet stimulated breast cancer initiation and progression are currently unclear. In this study, we examined how the intensity of physical activity influences high fat diet-stimulated breast cancer latency and progression outcomes, and the possible mechanisms behind these effects. Five-week-old female Balb/c mice were fed either a control diet or a high-fat diet for 8 weeks, and then 4T1 mouse mammary tumor cells were inoculated into the mammary fat pads. Exercise training occurred before tumor cell injection, and tumor latency and tumor volume were measured. Mice with a high-fat diet and low-intensity exercise (HFLE) had a longer tumor latency period, slower tumor growth, and smaller tumor volume in the final tumor assessment compared with the control, high-fat diet control (HFDC), and high-fat diet with moderate-intensity exercise (HFME) groups. Steady low- and moderate-intensity exercise had no effect on cell proliferation but induced apoptosis by activating caspase-3 through the alteration of Bcl-2, Bcl-xL, and Bax expression. Furthermore, steady exercise reduced M2 macrophage polarization in breast tumor tissue, which has been linked to tumor growth. The myokine, myostatin, reduced M2 macrophage polarization through the inhibition of the JAK-STAT signaling pathway. These results suggest that steady low-intensity exercise could delay breast cancer initiation and growth and reduce tumor volume through the induction of tumor cell apoptosis and the suppression of M2 macrophage polarization.

GDF11 Implications in Cancer Biology and Metabolism. Facts and Controversies

Growth Differentiation Factor 11 (GDF11), a member of the super family of the Transforming Growth Factor β, has gained more attention in the last few years due to numerous reports regarding its functions in other systems, which are different to those related to differentiation and embryonic development, such as age-related muscle dysfunction, skin biology, metabolism, and cancer. GDF11 is expressed in many tissues, including skeletal muscle, pancreas, kidney, nervous system, and retina, among others. GDF11 circulating levels and protein content in tissues are quite variable and are affected by pathological conditions or age. Although, GDF11 biology had a lot of controversies, must of them are only misunderstandings regarding the variability of its responses, which are independent of the tissue, grade of cellular differentiation or pathologies. A blunt fact regarding GDF11 biology is that its target cells have stemness feature, a property that could be found in certain adult cells in health and in disease, such as cancer cells. This review is focused to present and analyze the recent findings in the emerging research field of GDF11 function in cancer and metabolism, and discusses the controversies surrounding the biology of this atypical growth factor.

[Elevation of Myostatin as a Potential Marker for Compartment Syndrome in Electrical Injuries]

INTRODUCTION

Electrical accidents and particularly subsequent compartment syndromes are challenging injuries for clinical treatment. Creatinine kinase (CK) and myoglobin are known lab parameters to detect a compartment syndrome.

METHODS

We followed up patients with electrical injuries between the years 2006 and 2016 at our burn unit. We aimed to analyse the role of myostatin as marker for compartment syndrome through serum measurements within 48 hours after injury.

RESULTS

We collected data from 24 patients hospitalised with high-voltage electrical injury. All patients were male. We measured myostatin in 14 of these patients. While CK-MB (creatinine kinase muscle-brain type [MB]) showed no significant correlation to compartment syndrome, CK and myostatin gave highly significant increases. Interestingly, myostatin was significantly increased in electrical injuries but not burn injuries, while CK did not show a significant difference.

CONCLUSION

Thus, besides CK, myostatin can serve as reliable early marker for compartment syndrome in electrical injuries.

Activin Receptor 2 Antagonization Impairs Adipogenic and Enhances Osteogenic Differentiation in Mouse Adipose-Derived Stem Cells and Mouse Bone Marrow-Derived Stem Cells In Vitro and In Vivo

Tumors, traumata, burn injuries or surgeries can lead to critical-sized bony defects which need to be reconstructed. Mesenchymal stem cells (MSCs) have the ability to differentiate into multiple cell lineages and thus present a promising alternative for use in tissue engineering and reconstruction. However, there is an ongoing debate whether all MSCs are equivalent in their differentiation and proliferation ability. The goal of this study was to assess osteogenic and adipogenic characteristic changes of adipose-derived stem cells (ASCs) and bone marrow-derived stem cells (BMSCs) upon Myostatin inhibition with Follistatin in vitro and in vivo. We harvested ASCs from mice inguinal fat pads and BMSCs from tibiae of mice. By means of histology, real-time cell analysis, immunohistochemistry, and PCR osteogenic and adipogenic proliferation and differentiation in the presence or absence of Follistatin were analyzed. In vivo, osteogenic capacity was investigated in a tibial defect model of wild-type (WT) mice treated with mASCs and mBMSCs of Myo^-/- and WT origin. In vitro, we were able to show that inhibition of Myostatin leads to markedly reduced proliferative capacity in mBMSCs and mASCs in adipogenic differentiation and reduced proliferation in osteogenic differentiation in mASCs, whereas proliferation in mBMSCs in osteogenic differentiation was increased. Adipogenic differentiation was inhibited in mASCs and mBMSCs upon Follistatin treatment, whereas osteogenic differentiation was increased in both cell lineages. In vivo, we could demonstrate increased osteoid formation in WT mice treated with mASCs and mBMSCs of Myo^-/- origin and enhanced osteogenic differentiation and proliferation of mASCs of Myo^-/- origin. We could demonstrate that the osteogenic potential of mASCs could be raised to a level comparable to mBMSCs upon inhibition of Myostatin. Moreover, Follistatin treatment led to inhibition of adipogenesis in both lineages.

Genetic, epigenetic and transcriptional comparison of esophagus tumor‑associated and adjacent normal myofibroblasts

Myofibroblasts (MFs) are present in healthy tissues and are also key components of the tumor microenvironment. In the present study a comparative analysis of MFs obtained from various gastrointestinal tumor tissues and from tumor-adjacent normal tissues of cancer patients was performed, with the aim to evaluate differences in MF morphology, gene expression profile and function. The goal was to correlate the observed morphological and functional variations with the underlying genetic and epigenetic backgrounds. The mutation frequency of MFs was assessed by next generation sequencing. The transcript levels of cancer-specific genes were determined by TaqMan array and quantitative polymerase chain reaction. Epigenetic modifications were analyzed by immunocytochemistry and western blotting. The migratory capacity of MFs was assessed by scratch assay, whereas matrix metalloproteinase expression and activity were obtained by quantitative polymerase chain reaction and zymography. The results of the present study demonstrate that MFs were present in an increased number and with altered morphology in tumor samples compared with the healthy tissue. Although the detected number of mutations in tumor-associated and normal tissue-derived MFs did not differ markedly, shifts in the level of specific acetylated and methylated histone proteins, namely decreased levels of trimethylated H3K9 and acetylated H4K16 were demonstrated in tumor-associated MFs. Transcript levels of several tumor-specific genes involved in metastasis, regulation of cellular growth, apoptosis, as well as in hypoxia-angiogenesis were altered in tumor-derived MF cultures. Increased mRNA levels were obtained and activity of matrix metalloproteases in tumor-derived MFs and these cells also exhibited a higher migratory capacity compared with the normal MFs. In summary, the results of the present study indicate that tumor-associated MFs display an altered phenotype compared with healthy tissue derived counterparts. The results imply that epigenetic rather than genetic alterations are associated with the development of the distinct expressional and functional features, which define this MF phenotype in the tumor microenvironment.

Myostatin serum concentration as an indicator for deviated muscle metabolism in severe burn injuries

INTRODUCTION

Patients experiencing thermal injuries with an extent of over 20% of total body surface area suffer from systemic catabolic disease. The thermal trauma-induced loss of muscle mass causes a higher incidence for comorbidities and subsequently a higher mortality. In this study, we aimed to investigate the role of myostatin in the interplay with follistatin during muscle cachexia.

METHODS

Patients with burn injuries (>10% total body surface area) between the ages of 18 and 75 were prospectively included within the first 48 h after trauma to determine deviations of parameters connected to muscle catabolism. In the chronic state of burn injury (9-12 months after trauma), we re-evaluated myostatin and follistatin concentrations as well as muscle strength of the non-dominant forearm.

RESULTS

We were able to show a time-dependent alteration (9-12 months after burn injury) of myostatin with an initial decrease (p < 0.001) and long-term increase (p < 0.001) after thermal injury in blood serum. For follistatin, a reciprocal correlation was observed (r = -0.707, p = 0.001). Accordingly, muscle strength of the non-dominant hand and forearm was significantly decreased 9-12 months after injury in post-burn patients compared with healthy patients with a significant correlation to myostatin levels (r = -0.899, p < 0.001). In addition, initial myostatin serum concentration was predictive for long-term muscle strength impairment.

CONCLUSION

With regard to the muscle metabolism after thermal trauma, our data suggest an acute anabolic response, presumably to spare muscle mass, which is converted to catabolic conditions accompanied by muscle strength reduction in the chronic phase. Myostatin plays a crucial role in this orchestration and initial myostatin concentration may predict the long-term muscle strength.