The stem cell factor (SCF)/c-KIT signalling in testis and prostate cancer

Investigating the effects of cytokine biomarkers on HIV incidence: a case study for individuals randomized to pre-exposure prophylaxis vs. control

Introduction

Understanding and identifying the immunological markers and clinical information linked with HIV acquisition is crucial for effectively implementing Pre-Exposure Prophylaxis (PrEP) to prevent HIV acquisition. Prior analysis on HIV incidence outcomes have predominantly employed proportional hazards (PH) models, adjusting solely for baseline covariates. Therefore, models that integrate cytokine biomarkers, particularly as time-varying covariates, are sorely needed.

Methods

We built a simple model using the Cox PH to investigate the impact of specific cytokine profiles in predicting the overall HIV incidence. Further, Kaplan-Meier curves were used to compare HIV incidence rates between the treatment and placebo groups while assessing the overall treatment effectiveness. Utilizing stepwise regression, we developed a series of Cox PH models to analyze 48 longitudinally measured cytokine profiles. We considered three kinds of effects in the cytokine profile measurements: average, difference, and time-dependent covariate. These effects were combined with baseline covariates to explore their influence on predictors of HIV incidence.

Results

Comparing the predictive performance of the Cox PH models developed using the AIC metric, model 4 (Cox PH model with time-dependent cytokine) outperformed the others. The results indicated that the cytokines, interleukin (IL-2, IL-3, IL-5, IL-10, IL-16, IL-12P70, and IL-17 alpha), stem cell factor (SCF), beta nerve growth factor (B-NGF), tumor necrosis factor alpha (TNF-A), interferon (IFN) alpha-2, serum stem cell growth factor (SCG)-beta, platelet-derived growth factor (PDGF)-BB, granulocyte macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and cutaneous T-cell-attracting chemokine (CTACK) were significantly associated with HIV incidence. Baseline predictors significantly associated with HIV incidence when considering cytokine effects included: age of oldest sex partner, age at enrollment, salary, years with a stable partner, sex partner having any other sex partner, husband's income, other income source, age at debut, years lived in Durban, and sex in the last 30 days.

Discussion

Overall, the inclusion of cytokine effects enhanced the predictive performance of the models, and the PrEP group exhibited reduced HIV incidences compared to the placebo group.

Basic concepts of cancer genetics and receptor tyrosine kinase inhibition for pharmacists. A narrative review

The intent of this review is to present basic genetic concepts key to understanding oncogenesis and the role receptor tyrosine kinase (RTK) inhibition plays in the targeted treatment of many cancer types. Oncogenic signaling by RTKs can result from genetic events such as point mutations, chromosomal rearrangements, structural variation, and gene amplification in the cancer genome. The cancer pharmacogenes discussed encode RTKs that exemplify the link between gene variation, the oncogenic process, and the basis of targeted approaches to treatment. Biochemical pathways often involved in oncogenesis and affected by RTK variation are reviewed. Molecular diagnostic testing for the presence of specific gene variants, alterations, and amplifications direct therapy to indicated tyrosine kinase inhibitors and monoclonal antibody drugs. As pharmacists are integral to the selection, preparation, and monitoring of chemotherapy, it is important that they understand the genetic basis for targeted therapies as well as the underlying disease process.

SCF/c-Kit-activated signaling and angiogenesis require Gαi1 and Gαi3

The stem cell factor (SCF) binds to c-Kit in endothelial cells, thus activating downstream signaling and angiogenesis. Herein, we examined the role of G protein subunit alpha inhibitory (Gαi) proteins in this process. In MEFs and HUVECs, Gαi1/3 was associated with SCF-activated c-Kit, promoting c-Kit endocytosis, and binding of key adaptor proteins, subsequently transducing downstream signaling. SCF-induced Akt-mTOR and Erk activation was robustly attenuated by Gαi1/3 silencing or knockout (KO), or due to dominant negative mutations but was strengthened substantially following ectopic overexpression of Gαi1/3. SCF-induced HUVEC proliferation, migration, and capillary tube formation were suppressed after Gαi1/3 silencing or KO, or due to dominant negative mutations. In vivo, endothelial knockdown of Gαi1/3 by intravitreous injection of endothelial-specific shRNA adeno-associated virus (AAV) potently reduced SCF-induced signaling and retinal angiogenesis in mice. Moreover, mRNA and protein expressions of SCF increased significantly in the retinal tissues of streptozotocin-induced diabetic retinopathy (DR) mice. SCF silencing, through intravitreous injection of SCF shRNA AAV, inhibited pathological retinal angiogenesis and degeneration of retinal ganglion cells in DR mice. Finally, the expression of SCF and c-Kit increased in proliferative retinal tissues of human patients with proliferative DR. Taken together, Gαi1/3 mediate SCF/c-Kit-activated signaling and angiogenesis.

KIT Mutations Correlate with Higher Galectin Levels and Brain Metastasis in Breast and Non-Small Cell Lung Cancer

To investigate a potential role for galectins as biomarkers that enable diagnosis or prognostication of breast or non-small cell lung cancer, the serum levels of galectins -1, -3, -7, -8, and -9 of cancer patients determined by ELISA assays were compared to the mutation status of 50 known cancer-critical genes, which were determined using multiplex PCR in tumors of the same patients. Mutations in the KIT proto-oncogene, which codes for the c-Kit protein, a receptor tyrosine kinase, correlated with higher levels of galectins -1, -3, -8, and -9 in breast cancer patients and galectin-1 in non-small cell lung cancer patients. Mutations in the KIT gene were more likely found in brain metastases from both of these primary cancers. The most common KIT mutation in our panel was p.M541L, a missense mutation in the transmembrane domain of the c-Kit protein. These results demonstrate an association between KIT oncogenic signaling and elevated serum galectins in patients with metastatic disease. Changes in protein trafficking and the glycocalyx composition of cancer cells may explain the observed alterations in galectin expression. This study can be useful for the targeted selection of receptor tyrosine kinase and galectin inhibitor anti-cancer treatments.

Stimulation of C-Kit+ Retinal Progenitor Cells by Stem Cell Factor Confers Protection Against Retinal Degeneration

C-kit/CD117, expressed in a series of tissue-specific progenitor cells, plays an important role in tissue regeneration and tissue homeostasis. We previously demonstrated that organoid-derived c-kit⁺ retinal progenitor cells can facilitate the restoration of degenerated retina. Meanwhile, we have identified a population of endogenous c-kit⁺ cells in retinas of adult mouse. However, the exact role of these cells in retinal degeneration remains unclear. Here, we demonstrated that stimulation of endogenous c-kit⁺ cells by stem cell factor (SCF) conferred protection against retinal degeneration. Retinal degeneration was induced by intravitreal injection of N-methyl-D-aspartate (NMDA). NMDA challenge increased the total number of c-kit⁺ cells in the retinal ganglion cell layer (GCL), while deregulated the protein level of SCF, which was mainly expressed in Müller cells. Both flash electroretinogram (fERG) and light/dark transition tests showed that intravitreal injection of SCF effectively improved the visual function of NMDA-treated mice. Mechanistically, SCF administration not only prevented the loss of retinal ganglion cells (RGCs), but also maintained the function of RGCs as quantified by fERG. Further, we performed transcriptome sequencing analysis of the retinal cells isolated from SCF-treated mice and the parallel control. Gene Ontology analysis showed that SCF-induced transcriptome changes were closely correlated with eye development-related pathways. Crystallins and several protective factors such as Pitx3 were significantly upregulated by SCF treatment. Our results revealed the role of SCF stimulated c-kit⁺ cells in the protection of RGCs in NMDA-treated mice, via inhibiting the loss of RGCs. Administration of SCF can act as a potent strategy for treating retinal degeneration-related diseases.

Long-Term Wi-Fi Exposure From Pre-Pubertal to Adult Age on the Spermatogonia Proliferation and Protective Effects of Edible Bird’s Nest Supplementation

Children are vulnerable to the radiofrequency radiation (RFR) emitted by Wi-Fi devices. Nevertheless, the severity of the Wi-Fi effect on their reproductive development has been sparsely available. Therefore, this study was conducted to evaluate the Wi-Fi exposure on spermatogonia proliferation in the testis. This study also incorporated an approach to attenuate the effect of Wi-Fi by giving concurrent edible bird’s nest (EBN) supplementation. It was predicted that Wi-Fi exposure reduces spermatogonia proliferation while EBN supplementation protects against it. A total of 30 (N = 30) 3-week-old Sprague Dawley weanlings were divided equally into five groups; Control, Control EBN, Wi-Fi, Sham Wi-Fi, and Wi-Fi + EBN. 2.45 GHz Wi-Fi exposure and 250 mg/kg EBN supplementation were conducted for 14 weeks. Findings showed that the Wi-Fi group had decreased in spermatogonia mitosis status. However, the mRNA and protein expression of c-Kit-SCF showed no significant decrease. Instead, the reproductive hormone showed a reduction in FSH and LH serum levels. Of these, LH serum level was decreased significantly in the Wi-Fi group. Otherwise, supplementing the Wi-Fi + EBN group with 250 mg/kg EBN resulted in a significant increase in spermatogonia mitotic status. Even though EBN supplementation improved c-Kit-SCF mRNA and protein expression, the effects were insignificant. The improvement of spermatogonia mitosis appeared to be associated with a significant increase in blood FSH levels following EBN supplementation. In conclusion, the long-term Wi-Fi exposure from pre-pubertal to adult age reduces spermatogonia proliferation in the testis. On the other hand, EBN supplementation protects spermatogonia proliferation against Wi-Fi exposure.

CNV Hotspots in Testicular Seminoma Tissue and Seminal Plasma

Seminoma (SE) is the most frequent type of testicular tumour, affecting predominantly young men. Early detection and diagnosis of SE could significantly improve life quality and reproductive health after diagnosis and treatment. Copy number variation (CNV) has already been associated with various cancers as well as SE. In this study, we selected four genes (MAGEC2, NANOG, RASSF1A, and KITLG) for CNV analysis in genomic DNA (gDNA), which are located on chromosomes susceptible to gains, and whose aberrant expression was already detected in SE. Furthermore, CNV was analysed in cell-free DNA (cfDNA) from seminal plasma. Analysis was performed by droplet digital polymerase chain reaction (ddPCR) on gDNA from SE and nonmalignant testicular tissue. Seminal plasma cfDNA from SE patients before and after surgery was analysed, as well as from healthy volunteers. The CNV hotspot in gDNA from SE tissue was detected for the first time in all analysed genes, and for two genes, NANOG and KITLG it was reflected in cfDNA from seminal plasma. Although clinical value is yet to be determined, presented data emphasize a potential use of CNV as a potential SE biomarker from a liquid biopsy.

Protein kinase A drives paracrine crisis and WNT4-dependent testis tumor in Carney complex

Large-cell calcifying Sertoli cell tumors (LCCSCTs) are among the most frequent lesions occurring in male Carney complex (CNC) patients. Although they constitute a key diagnostic criterion for this rare multiple neoplasia syndrome resulting from inactivating mutations of the tumor suppressor PRKAR1A, leading to unrepressed PKA activity, LCCSCT pathogenesis and origin remain elusive. Mouse models targeting Prkar1a inactivation in all somatic populations or separately in each cell type were generated to decipher the molecular and paracrine networks involved in the induction of CNC testis lesions. We demonstrate that the Prkar1a mutation was required in both stromal and Sertoli cells for the occurrence of LCCSCTs. Integrative analyses comparing transcriptomic, immunohistological data and phenotype of mutant mouse combinations led to the understanding of human LCCSCT pathogenesis and demonstrated PKA-induced paracrine molecular circuits in which the aberrant WNT4 signal production is a limiting step in shaping intratubular lesions and tumor expansion both in a mouse model and in human CNC testes.

Therapeutic Effect of Stem Cells on Male Infertility in a Rat Model: Histological, Molecular, Biochemical, and Functional Study

Methotrexate (MTX) is a folic acid antagonist, widely used as a chemotherapeutic and immunosuppressive drug, but it is toxic to reproductive systems. In recent years, the era of stem cell applications becomes a promising point as a possible therapeutic agent in male infertility. This study is aimed at evaluating the therapeutic effects of stem cells at histological, molecular, biochemical, and functional levels in a methotrexate-induced testicular damage model. Material and Methods. Thirty rats were divided randomly into three groups (ten rats each): group 1 (control): animals received an intraperitoneal injection of 2 ml phosphate-buffered saline per week for 4 weeks, group 2 (MTX-treated group): animals were intraperitoneally injected with methotrexate (8 mg/kg) once weekly for 4 weeks, and group 3 (ADMSC-treated group): methotrexate-treated animals received a single dose of 1 × 10⁶ stem cells/rat at the 5th week. At the 8th week, blood samples were collected for hormonal analysis; then, animals were sacrificed. The testes were dissected; the right testis was stained with hematoxylin and eosin. Random sections were taken from group 3 and examined with a fluorescent microscope. The left testis was divided into two specimens: the first was used for an electron microscope and the second was homogenized for molecular and biochemical assessments. Results. Group 2 showed significant histological changes, decreased free testosterone level, decrease in stem cell factor expression, and dysfunction of the oxidation state. The results revealed significant improvement of these parameters. Conclusion. Transplantation of adipose tissue-derived stem cells (ADMSCs) can improve the testicular damage histologically and functionally in a rat model.

A holistic view on c-Kit in cancer: Structure, signaling, pathophysiology and its inhibitors

Receptor tyrosine kinases play an important role in many cellular processes, and their dysregulation leads to diseases, most importantly cancer. One such receptor tyrosine kinase is c-Kit, a type-III receptor tyrosine kinase, which is involved in various intracellular signaling pathways. The role of different mutant isoforms of c-Kit has been established in several types of cancers. Accordingly, promising c-Kit inhibition results have been reported for the treatment of different cancers (e.g., gastrointestinal stromal tumors, melanoma, acute myeloid leukemia, and other tumors). Therefore, lots of effort has been put to target c-Kit for the treatment of cancer. Here, we provide a comprehensive compilation to provide an insight into c-Kit inhibitor discovery. This compilation provides key information regarding the structure, signaling pathways related to c-Kit, and, more importantly, pharmacophores, binding modes, and SAR analysis for almost all small-molecule heterocycles reported for their c-Kit inhibitory activity. This work could be used as a guide in understanding the basic requirements for targeting c-Kit, and how the selectivity and efficacy of the molecules have been achieved till today.

Tissue distribution of stem cell factor in adults

Stem cell factor (SCF) is an essential cytokine during development and is necessary for gametogenesis, hematopoiesis, mast cell development, stem cell function, and melanogenesis. Here, we measure SCF concentration and distribution in adult humans and mice using gene expression analysis, tissue staining, and organ protein lysates. We demonstrate continued SCF expression in many cell types and tissues into adulthood. Tissues with high expression in adult humans included stomach, spleen, kidney, lung, and pancreas. In mice, we found high SCF expression in the esophagus, ovary, uterus, kidney, and small intestine. Future studies may correlate our findings of increased, organ-specific SCF concentrations within adult tissues with increased risk of SCF/CD117-related disease.

Current Insights into Interethnic Variability in Testicular Cancers: Population Pharmacogenetics, Clinical Trials, Genetic Basis of Chemotherapy- Induced Toxicities and Molecular Signal Transduction

Testicular cancer is an aggressive malignancy with a rising incidence rate across the globe. Testicular germ cell tumors are the most commonly diagnosed cancers, and surgical removal of the testes is often a radical necessity along with chemotherapy and radiotherapy. While seminomas are receptive to radiotherapy as well as chemotherapy, non-seminomatous germ cell tumors respond to chemotherapy only. Due to the singular nature of testicular cancers with associated orchiectomy and mortality, it is important to study the molecular basis and genetic underpinnings of this group of cancers across male populations globally. In this review, we shed light on the population pharmacogenetics of testicular cancer, pediatric and adult tumors, current clinical trials, genetic determinants of chemotherapy-induced toxicity in testicular cancer, as well as the molecular signal transduction pathways operating in this malignancy. Taken together, our discussions will help in enhancing our understanding of genetic factors in testicular carcinogenesis and chemotherapy-induced toxicity, augment our knowledge of this aggressive cancer at the cellular and molecular level, as well as improve precision medicine approaches to combat this disease.

Treatment of Metastatic Gastrointestinal Stromal Tumors (GIST): A Focus on Older Patients

Gastrointestinal stromal tumors (GIST) originating in the Cajal cells are the most common mesenchymal neoplasms of the gastrointestinal tract. The median age of patients with this diagnosis is 65 years, and over 20% of cases affect people over the age of 70 years. The effectiveness and tolerability of systemic treatment with tyrosine kinase inhibitors in older patients with GIST seem to be similar to that in younger patients, but some studies have shown that treatment of older patients is suboptimal. Disability, frailty, comorbidities, and concomitant medications may influence treatment decisions, and toxicities also more often lead to treatment discontinuation. The known safety profile and oral administration route of the tyrosine kinase inhibitors used in GIST may allow maximization of treatment and the best efficacy, especially in older patients. This review summarizes the efficacy data for the systemic treatment of GIST, including data for older patients and from real-world experiences, if available and significant. The reported safety data and general rules for toxicity management, including appropriate patient selection and the need for careful monitoring during treatment, are also discussed.

Characterization of DDX4 Gene Expression in Human Cases with Non-Obstructive Azoospermia and in Sterile and Fertile Mice

Background

In mammals, spermatogenesis is the main process for male fertility that is initiated by spermatogonial stem cells (SSCs) proliferation. SSCs are unipotent progenitor cells accountable for transferring the genetic information to the following generation by differentiating to haploid cells during spermato-and spermiogenesis. DEAD-box helicase 4 (DDX4) is a specific germ cell marker and its expression pattern is localized to, spermatocytes, and spermatids. The expression in the SSCs on the basement membrane of the seminiferous tubules is low.

Methods

Immunohistochemistry (IHC) and Fluidigm reverse transcriptase-polymerase chain reaction (RT-PCR) were used to analyze the expression of DDX4 in testis tissue of fertile and sterile mice and human cases with non-obstructive azoospermia.

Results

Our immunohistochemical findings of fertile and busulfan-treated mice showed expression of DDX4 in the basal and luminal compartment of seminiferous tubules of fertile mice whereas no expression was detected in busulfan-treated mice. The immunohistochemical analysis of two human cases with different levels of non-obstructive azoospermia revealed more luminal DDX4 positive cells.

Conclusion

Our findings indicate that DDX4 might be a valuable germ cell marker for analyzing the pathology of germ cell tumors and infertility as global urological problems.

SCF Improves In Vitro Differentiation of SSCs Through Transcriptionally Up-regulating PRTM1, STRA8, c-KIT, PIWIL2, and OCT4 Genes

Several lines of evidence strongly suggest that retinoic acid (RA) and stem cell factor (SCF)/c-Kit signal transduction pathways are involved in the differentiation of spermatogonial stem cells (SSCs). This study was aimed to investigate the effect of RA and SCF on in vitro differentiation of SSCs via evaluation of the mRNA expression of meiosis-specific genes in cultured testicular tissues. Testicular tissue samples were obtained from bilaterally vasectomized rats and also healthy adult rats and then were cultured for 25, 30, and 35 days on different conditions. The cultured testicular pieces were sectioned and stained with PAS to histological analysis. The total RNA was extracted from cultured testicular samples, and the expression of ACR, PRTM1, SYCP3, STRA8, c-KIT, PIWIL2, and OCT4 genes at mRNA level was quantified using real-time polymerase chain reaction (qPCR) procedure. After 1-month surgery, bilateral testicular weight showed a significant decrease in vasectomized adult rats compared with healthy adult rats (P < 0.05). Reduction in the diameter of the seminiferous tubules and depletion of advanced germinal elements in vasectomized rats compared with healthy adult rats were also observed. Our findings also demonstrated that the mRNA expression level of PRTM1, STRA8, c-KIT, PIWIL2, and OCT4 genes in cultured testicular tissues significantly up-regulated in experimental group II compared with the control group (P < 0.001). Our findings lead us to conclude that SCF improves in vitro differentiation of SSCs in the OA rats, at least partially, by transcriptionally upregulating PRTM1, STRA8, c-KIT, PIWIL2, and OCT4 genes.

Blood-based protein profiling identifies serum protein c-KIT as a novel biomarker for hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is one of the most common hereditary heart diseases and can be classified into an obstructive (HOCM) and non-obstructive (HNCM) form. Major characteristics for HCM are the hypertrophy of cardiomyocytes and development of cardiac fibrosis. Patients with HCM have a higher risk for sudden cardiac death compared to a healthy population. In the present study, we investigated the abundancy of selected proteins as potential biomarkers in patients with HCM. We included 60 patients with HCM and 28 healthy controls and quantitatively measured the rate of a set of 92 proteins already known to be associated with cardiometabolic processes via protein screening using the proximity extension assay technology in a subgroup of these patients (20 HCM and 10 healthy controls). After validation of four hits in the whole cohort of patients consisting of 88 individuals (60 HCM patients, 28 healthy controls) we found only one candidate, c-KIT, which was regulated significantly different between HCM patients and healthy controls and thus was chosen for further analyses. c-KIT is a tyrosine-protein kinase acting as receptor for the stem cell factor and activating several pathways essential for cell proliferation and survival, hematopoiesis, gametogenesis and melanogenesis. Serum protein levels of c-KIT were significantly lower in patients with HCM than in healthy controls, even after adjusting for confounding factors age and sex. In addition, c-KIT levels in human cardiac tissue of patients with HOCM were significant higher compared to controls indicating high levels of c-KIT in fibrotic myocardium. Furthermore, c-KIT concentration in serum significantly correlated with left ventricular end-diastolic diameter in HOCM, but not HCM patients. The present data suggest c-KIT as a novel biomarker differentiating between patients with HCM and healthy population and might provide further functional insights into fibrosis-related processes of HOCM.

The improved anticancer effects of Bortezomib-loaded hollow mesoporous silica nanospheres on lymphoma development

As the first clinical proteasome inhibitor, Bortezomib (BTZ) has been reported to improve the outcome of lymphoma. However, due to the unstable property, low bioavailability, and hydrophobic properties of BTZ, it is needed to develop effective drug delivery systems to deliver BTZ into targeted cells or organs. Here we developed a bortezomib (BTZ)-loaded HMSNs (BTZ@HMSNs) system, which can sustain the release of BTZ in targeted tissues. In vitro assays showed that BTZ@HMSNs limited cell proliferation and augmented apoptosis of lymphoma SNK-1 cells. Moreover, BTZ@HMSNs significantly diminished migration and invasion of SNK-1 cells as compared with BTZ. In contrast to the upregulation of SHP-1, BTZ@HMSNs decreased the mRNA levels of c-Kit, NF-κB, and JAK1, which elicit oncogenic role in lymphoma development. Importantly, lymphoma mice model showed that BTZ@HMSNs significantly activated p53 signaling and reduced tumor volume and weight compared with free BTZ. Our data thus demonstrate that BTZ@HMSNs manifests improved tumor-suppressing effect in vitro and in vivo compared to free BTZ. We believe that HMSNs is a promising strategy for delivering therapeutic agents for cancer treatment.

Investigation of EGFR/pi3k/Akt signaling pathway in seminomas

Activation of the receptor for epidermal growth factor (EGFR) in some testicular tumors activates several signaling pathways. Some components of these pathways are phosphorylated or mutated in testicular germ tumors (TCGT), including EGFR, Kirstein ras oncogen (KRAS) and cell surface protein of the germ cell (KIT). The latter two activate RAF ⁄MEK⁄ERK and PI3 K⁄AKT, and interconnect with the EGFR/pI3 k/Akt pathway. We investigated the expression of EGFR/pI3 k/Akt pathway proteins in seminomas and in their precursor lesion, germinal cell neoplasia in situ (GCNIS) and related genetic mutations. We used immunohistochemistry for pEGFR, pI3 k and pAkt expression with a scoring system for 46 seminoma surgical specimens: 36 classical and 10 GCNIS. In 17 samples, the mutations of EGFR (exons 19 - 21), KIT (exons 11, 17) and KRAS (exons 2, 3) were investigated using qPCR and sequencing. Of the 36 seminomas studied, 22 (61%) expressed pEGFR. Ten samples exhibited high scores for pEGFR, pI3 k and pAkt. In 5 of 17 cases (33%) some mutation was exhibited in the exons studied: 21 of EGFR (2), 17 of EGFR (1), 3 of KRAS (1) and 11 of KIT (1). Six cases exhibited nuclear translocation of EGFR; of these, four exhibited mutations of EGFR, KRAS and KIT. Eight of ten of the GCNIS expressed a high pEGFR score (80%). In 2 of 6 cases (33%), mutation was detected in exon 21 of EGFR and one smear showed EGFR translocation to the nucleus. The translocation represents a subpopulation with worse prognosis for TCGT. The EGFR/pI3 k/Akt signaling pathway is linked to TDRG1, which regulates chemosensitivity to cisplatin; this is a mechanism of resistance to treatment. TDRG1 and the EGFR/pI3 k/pAkt pathway could be therapeutic targets for seminomas resistant to cisplatin.

Molecular Pathways and Targeted Therapies for Malignant Ovarian Germ Cell Tumors and Sex Cord-Stromal Tumors: A Contemporary Review

Non-epithelial ovarian tumors are heterogeneous and account for approximately 10% of ovarian malignancies. The most common subtypes of non-epithelial ovarian tumors arise from germ cells or sex cord and stromal cells of the gonads. These tumors are usually detected at an early stage, and management includes surgical staging and debulking. When indicated for advanced disease, most respond to chemotherapy; however, options for patients with refractory disease are limited, and regimens can be associated with significant toxicities, including permanent organ dysfunction, secondary malignancies, and death. Targeted therapies that potentially decrease chemotherapy-related adverse effects and improve outcomes for patients with chemotherapy-refractory disease are needed. Here, we review the molecular landscape of non-epithelial ovarian tumors for the purpose of informing rational clinical trial design. Recent genomic discoveries have uncovered recurring somatic alterations and germline mutations in subtypes of non-epithelial ovarian tumors. Though there is a paucity of efficacy data on targeted therapies, such as kinase inhibitors, antibody–drug conjugates, immunotherapy, and hormonal therapy, exceptional responses to some compounds have been reported. The rarity and complexity of non-epithelial ovarian tumors warrant collaboration and efficient clinical trial design, including high-quality molecular characterization, to guide future efforts.

Association between Circulation Indole-3-Acetic Acid Levels and Stem Cell Factor in Maintenance Hemodialysis Patients: A Cross-Sectional Study

Protein-bound uremic toxin is a cardiovascular (CV) risk factor for patients with end-stage renal disease. Indole-3-acetic acid (IAA) was found to be associated with CV disease but the detailed pathophysiology remains unknown. Moreover, mitogen-activated protein kinase (MAPK) signaling cascades play an important role in the pathogenesis of CV disease. Thus, we explored the association between circulating IAA levels and forty MAPK cascade associated proteins in patients undergoing hemodialysis (HD). Circulating total form IAA was quantified by mass spectrometry and forty MAPK cascade associated proteins by a proximity extension assay in 331 prevalent HD patients. Accounting for multiple testing, and in multivariable-adjusted linear regression models, circulating total form IAA levels were positively associated with stem cell factor (β coefficient 0.13, 95% confidence interval 0.04 to 0.21, p = 0.004). A bioinformatics approach using the search tool for interactions of chemicals (STITCH) tool provided information that IAA may be involved in the regulation of cell proliferation, hematopoietic cells, and the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway. The knowledge gained here can be generalized, thereby impacting the non-traditional CV risk factors in patients with kidney disease. Further in vitro work is necessary to validate the translation of the mechanistic pathways.

Role of TGF-β1 and C-Kit Mutations in the Development of Hepatocellular Carcinoma in Hepatitis C Virus-Infected Patients: in vitro Study

Transforming growth factor beta (TGF-β) acts as a tumor-suppressing cytokine in healthy tissues and non-malignant tumors. Yet, in malignancy, TGF-β can exert the opposite effects that can promote proliferation of cancer cells. C-Kit plays a prominent role in stem cell activation and liver regeneration after injury. However, little is known about the cross-talk between TGF-β and C-Kit and its role in the progression of hepatocellular carcinoma (HCC). Here, we studied the effect of increasing doses of TGF-β1 on CD44⁺CD90⁺ liver stem cells (LSCs) and C-Kit gene expression in malignant and adjacent non-malignant liver tissues excised from 32 HCC patients. The percentage of LSCs in malignant tumors was two times higher compared to their counterparts from the non-malignant tissues. When treated with increasing doses of TGF-β1, proliferation of both malignant and non-malignant LSCs was progressively suppressed, but low TGF-β1 dose failed to suppress the growth of malignant LSCs. Moreover, C-Kit exons 9 and 11 were expressed in malignant LSCs, but not in their non-malignant counterparts. Analysis of C-Kit detected mutations in exon 9 (but not in exon 11) in some malignant liver cells resulting in the changes in the amino acid sequence and dysregulation of protein structure and function. Interestingly, in malignant liver cells, mutations in exon 9 were associated with high-viremia hepatitis C virus (HCV), and expression of this exon was not suppressed by the TGF-β1 treatment at all doses. To our knowledge, this is the first report that mutations in the C-Kit gene in HCC patients are associated with high- viremia HCV. Our study emphasizes the need for investigation of the TGF-β1 level and C-Kit mutations in patients with chronic HCV for HCC prevention and better therapy management.

In vitro and in vivo evaluation of possible pro-survival activities of PGE2, EGF, TPO and FLT3L on human hematopoiesis

Myelosuppression is a major and frequently dose-limiting side effect of anticancer therapy and is responsible for most treatment-related morbidity and mortality. In addition, repeated cycles of DNA damage and cell death of hematopoietic stem and progenitor cells, followed by compensatory proliferation and selection pressure, lead to genomic instability and pave the way for therapy-related myelodysplastic syndromes and secondary acute myeloid leukemia. Protection of hematopoietic stem and progenitor cells from chemo- and radiotherapy in patients with solid tumors would reduce both immediate complications and long-term sequelae. Epidermal growth factor (EGF) and prostaglandin E2 (PGE2) were reported to prevent chemo- or radiotherapy-induced myelosuppression in mice. We tested both molecules for potentially protective effects on human CD34⁺ cells in vitro and established a xenograft mouse model to analyze stress resistance and regeneration of human hematopoiesis in vivo. EGF was neither able to protect human stem and progenitor cells in vitro nor to promote hematopoietic regeneration following sublethal irradiation in vivo. PGE2 significantly reduced in vitro apoptotic susceptibility of human CD34⁺ cells to taxol and etoposide. This could, however, be ascribed to reduced proliferation rather than to a change in apoptosis signaling and BCL-2 protein regulation. Accordingly, 16,16-dimethyl-PGE2 (dmPGE2) did not accelerate regeneration of the human hematopoietic system in vivo. Repeated treatment of sublethally irradiated xenograft mice with known antiapoptotic substances, such as human FLT3L and thrombopoietin (TPO), which suppress transcription of the proapoptotic BCL-2 proteins BIM and BMF, also only marginally promoted human hematopoietic regeneration in vivo.

Prognostic and Clinic-Pathological Significances of SCF and COX-2 Expression in Inflammatory and Malignant Prostatic Lesions

The initiation of prostatic malignancy has been linked to chronic inflammation. Stem cell factor (SCF) is an inflammatory cytokine that is specific to the c-KIT receptor which is type III receptor tyrosine kinase (RTK). Cyclooxygenases (COXs) are the main enzymes which are responsible for prostaglandins production from arachidonic acid. COX2 is an enzyme which is produced under different pathological conditions. The aim of our study; is to investigate the clinicopathological and the prognostic significance of SCF and COX-2 expression in prostatic adenocarcinoma (PC), chronic prostatitis and nodular prostatic hyperplasia (NPH) in a trial to clarify the role of inflammation as a risk factor for prostatic carcinogenesis and cancer progression. SCF and COX-2 tissue protein expression were evaluated in 50 cases of PC, 20 cases of chronic prostatitis and 10 cases of NPH using immunohistochemistry, patients were followed up for 5 years. The relationship between their levels of expressions, clinicopathological, and prognostic criteria were studied. SCF expression in PC was positively correlated with advanced patient age (p = <0.001), high level of PSA (p = 0.010), higher Gleason score (p = 0.011). COX-2 expression in PC was positively correlated with advanced patient age (p = <0.001), high level of PSA (p = 0.016), advanced D'Amico risk group (p = 0.038). High levels of expression of both SCF& COX-2 are associated with higher incidence of tumor relapse, worse disease overall survival and free survival (p < 0.001). SCF and COX-2 are associated with PC progression and associated with poor prognosis in PC patients.

Acquired platelet antagonism: off-target antiplatelet effects of malignancy treatment with tyrosine kinase inhibitors

Platelets can contribute to tumor progression and metastasis. Cancer patients are at increased risk of thrombosis, and advanced stages of cancer are associated with thrombocytosis or increased platelet reactivity. Tyrosine kinase inhibitors (TKIs) are widely used as a targeted strategy for cancer treatment, with the aim of prolonging progression-free survival of the patients. Because of their broad kinase target spectrum, most TKIs inevitably have off-target effects. Platelets rely on tyrosine kinase activity for their activation. Frequently observed side effects are lowering of platelet count and inhibition of platelet functions, whether or not accompanied by an increased bleeding risk. In this review, we aim to give insights into: (i) 38 TKIs that are currently used for the treatment of different types of cancer, either on the market or in clinical trials; (ii) how distinct TKIs can inhibit activation mechanisms in platelets; and (iii) the clinical consequences of the antiplatelet effects of TKI treatment. For several TKIs, the knowledge on affinity for their targets does not align with the published effects on platelets and reported bleeding events. This review should raise awareness of the potential antiplatelet effects of several TKIs, which will be enhanced in the presence of antithrombotic drugs.

Expression of tumour progression-associated genes in circulating tumour cells of patients at different stages of prostate cancer

OBJECTIVE

To evaluate the presence of circulating tumour cells (CTCs) at different stages of prostate cancer using the AdnaTest^® ProstateCancerDetect kit (Qiagen). Moreover, we aimed to assess the expression of transcripts that are specific for cancer stem cells (AdnaTest StemCell) and epithelial-mesenchymal transition (EMT) in CTCs (AdnaTest EMT), as well as additional genes that are known to promote prostate cancer progression.

PATIENTS AND METHODS

In this prospective study, we included 81 patients who underwent treatment for prostate cancer between 07/2014 and 02/2015, including: Group A, 18 patients (22.2%) with low-risk clinically localised prostate cancer; Group B, 25 patients (30.9%) with high-risk clinically localised prostate cancer; Group C, 11 patients (13.6%) with metastatic castration-sensitive prostate cancer (mCSPC); and Group D, 27 patients (33.3%) with metastatic castration-resistant prostate cancer (mCRPC). AdnaTest ProstateCancer and AdnaTest StemCell/EMT were performed in all cases. In addition, expression of the androgen receptor (AR), c-met, c-kit and thymidylate synthase (TYMS) in CTCs was assessed using specific polymerase chain reaction assays.

RESULTS

A positive AdnaTest ProstateCancer was present in three (16.7%), two (8.0%), six (54.5%) and 19 (70.5%) patients in groups A, B, C and D, respectively (P < 0.01, chi-squared test). The AdnaTest EMT and AdnaTest StemCell were positive in zero (0.0%), zero (0.0%), one (9.1%), and two (7.4%); and in five (27.8%), four (16.0%), three (27.3%), and 11 (40.7%) patients in groups A, B, C and D, respectively, with no significant differences noted between groups. CTCs expressing TYMS (44.4% and 50.0% vs 13.9%) or AR (18.2% and 25.9% vs 0.0%) were seen more commonly in patients in groups C and D vs patients with non-metastatic disease (all P < 0.05). Expression of c-kit and c-met were rare events, with only two patients positive for either marker.

CONCLUSIONS

AdnaTest ProstateCancerDetect exhibits positive results mainly in patients with metastatic disease. Expression of AR and TYMS are frequent events in CTCs of patients with advanced disease, whereas c-met and c-kit gene expression is seen in only a small proportion of patients. The implications of these results for the use of CTC analysis as a decision factor for personalised treatment strategies in advanced prostate cancer remain to be determined.

CD117/c-kit in Cancer Stem Cell-Mediated Progression and Therapeutic Resistance

Metastasis is the primary cause of cancer patient morbidity and mortality, but due to persisting gaps in our knowledge, it remains untreatable. Metastases often occur as patient tumors progress or recur after initial therapy. Tumor recurrence at the primary site may be driven by a cancer stem-like cell or tumor progenitor cell, while recurrence at a secondary site is driven by metastatic cancer stem cells or metastasis-initiating cells. Ongoing efforts are aimed at identifying and characterizing these stem-like cells driving recurrence and metastasis. One potential marker for the cancer stem-like cell subpopulation is CD117/c-kit, a tyrosine kinase receptor associated with cancer progression and normal stem cell maintenance. Further, activation of CD117 by its ligand stem cell factor (SCF; kit ligand) in the progenitor cell niche stimulates several signaling pathways driving proliferation, survival, and migration. This review examines evidence that the SCF/CD117 signaling axis may contribute to the control of cancer progression through the regulation of stemness and resistance to tyrosine kinase inhibitors.

Exploring the molecular aspects associated with testicular germ cell tumors: a review

Testicular germ cell tumors (TGCTs) represent the most common solid tumors affecting young men. They constitute a distinct entity because of their embryonic origin and their unique biological behavior. Recent preclinical data regarding biological signaling machinery as well as genetic and epigenetic mechanisms associated with molecular patterns of tumors have contribute to explain the pathogenesis and the differentiation of TGCTs and to understand the mechanisms responsible for the development of resistance to treatment. In this review, we discuss the main genetic and epigenetic events associated with TGCTs development in order to better define their role in the pathogenesis of these tumors and in cisplatin-acquired resistance.