Complications associated with chemotherapy in testicular cancer management

Identification and validation of Sertoli cell homing peptides as molecular steering for testis targeted drug delivery

The testicle, an organ privileged with immunity because of Blood-Testis Barrier (BTB), poses a major impediment to developing and delivering drugs to the testes. These problems can be prevented by targeting testicular cells using specific ligands, such as homing peptides. This is the first study to demonstrate the successful selection of Sertoli cell homing peptides using a phage display peptide library. The identification of peptides is performed with Sanger sequencing and high-throughput NGS. The Sertoli cell and testis targeting potential of the SCHP1 and SCHP2 was confirmed using confocal microscopy and flow cytometry of the FITC-labelled peptides and in vivo bio-distribution of the corresponding Cy5.5-tagged peptides. Secondary structures were predicted in the setting of different polarity by circular dichroism. The results suggest that SCHP1 and SCHP2 can effectively target Sertoli cells. In vivo bio-distribution in mouse models indicated significantly higher uptake of SCHP1 and SCHP2 by testes compared with the heart, brain, and spleen. SCHP1 and SCHP2 can be adopted as molecular steering for targeted male contraceptive delivery, treatment of testicular cancer, and male infertility. Further development of the peptides into peptidomimetics may increase their stability, and information on the molecular targets of these peptides may reveal their therapeutic potential.

Phase 2 Single-arm Trial of Primary Retroperitoneal Lymph Node Dissection in Patients with Seminomatous Testicular Germ Cell Tumors with Clinical Stage IIA/B (PRIMETEST)

BACKGROUND

Primary retroperitoneal lymph node dissection (RPLND) for clinical stage (CS) IIA/B seminoma without adjuvant treatment is an experimental treatment to avoid radiotherapy- or chemotherapy-related toxicity from standard treatment.

OBJECTIVE

The PRIMETEST trial aimed to prospectively evaluate the oncological efficacy and surgical safety of primary RPLND.

DESIGN, SETTING, AND PARTICIPANTS

PRIMETEST is a single-arm, single-center prospective phase 2 trial. Patients with seminoma, unilateral retroperitoneal lymph node metastases <5 cm, and human chorionic gonadotropin levels <5 mU/ml were included. Patients with CS IIA/B seminoma at initial diagnosis, and recurrence under active surveillance or following adjuvant carboplatin for CS I disease were eligible.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Unilateral open or robot-assisted primary RPLND was performed. The primary endpoint of the study was progression-free survival (PFS) after 36 mo. The trial was considered positive if <30% of patients experienced a recurrence.

RESULTS AND LIMITATIONS

Between 2016 and 2021, 33 patients were accrued (nine with primary CS IIA/B, 19 recurrences during active surveillance, and five recurrences following adjuvant carboplatin). Thirteen and 20 patients had CS IIA and IIB, respectively. Open and robot-assisted RPLND procedures were performed in 14 (42%) and 19 (58%) patients, respectively. After a median follow-up of 32 mo (interquartile range 23-46), ten recurrences were detected (30%, 95% confidence interval: 16-49%); thus, the primary endpoint was not met. Infield recurrences occurred in three of ten patients. The current analysis of risk factors could not identify the predictors of recurrence. Three of 33 patients (9%) presented with pN0.

CONCLUSIONS

The PRIMETEST trial did not meet its primary endpoint. Nevertheless, PFS of 70% after a median follow-up of 32 mo suggests this approach to be of interest for highly selected patients. Selection criteria, however, need to be defined and validated in a larger prospective cohort of patients. Until then, surgery alone for the treatment of patients with CS IIA/B seminoma cannot be recommended outside of a clinical trial setting.

PATIENT SUMMARY

In this study, we investigated primary surgery as an alternative to conventional treatment (chemotherapy or radiation therapy) in patients with metastatic seminoma. The primary objective of the study, to prevent at least 30% of patients from recurrence, was not met. However, certain patients may benefit from this approach and thereby avoid chemotherapy or radiation therapy. Predictive factors need to be analyzed to better select patients for this surgery-only approach.

Roasted cashew (Anacardium occidentale L.) nut-enhanced diet forestalls cisplatin-initiated brain harm in rats

The incessant dose constraining symptom of the chemotherapeutic agent, cisplatin is neurotoxicity. This examination tried to explore the neuroprotective impact of roasted cashew nut-enhanced diet against brain deficits related with treatment with cisplatin. Rats were separated in to six groups: Control, CIS (cisplatin [7 mg/kg body weight, i.p]), CIS +10% CN (cisplatin plus 10% roasted cashew nut), CIS +20% CN (cisplatin plus 20% roasted cashew nut), 10% CN (10% roasted cashew nut) and 20% CN (20% roasted cashew nut) for 28 days. Key enzymes associated with brain function, including cholinesterases (AChE and BChE), monoaminergic enzyme (MAO), arginase, and adenosine deaminase (ADA), were investigated after the treatment. The following oxidative stress indicators were also measured in the rat brain: glutathione-S-transferase (GST), glutathione peroxidase (GPx), total antioxidant capacity (TAC), total thiol (T-SH), non-protein thiol (NPSH), thiobarbituric acid reactive substances (TBARS), reactive oxygen species (ROS), nitric oxide (NO), superoxide dismutase (SOD). Our outcomes demonstrated that roasted cashew nut enhanced diet showed inhibitory impact on activities of AChE, BChE, ADA, MAO and arginase in cisplatin-induced rats. The roasted cashew nut supplemented diet also boosted redox equilibrium and displayed protection against cispaltin-induced oxidative damage to rats' brains by an increase in SOD, CAT, GST and GPx activities, TAC, T-SH, NPSH and NO levels as well as a considerable drop in ROS and RBARS levels. Roasted cashew nut enhanced diet additionally forestalled neuronal degeneration in rat brain. Thus, roasted cashew nuts could be used as a nutraceutical or functional food to treat cisplatin-induced neurotoxicity.

Practical applications

The results show that increasing roasted cashew nut consumption can significantly improve antioxidant status, reduce lipid peroxidation, and suppress cholinesterase, adenosine deaminase, monoamine oxidase, and arginase activities in the brain under cisplatin-induced circumstances.

Repurposing FDA-approved drugs against the toxicity of platinum-based anticancer drugs

Platinum-based anticancer drugs (PADs), mainly cisplatin, carboplatin, and oxaliplatin, are widely used efficacious long-standing anticancer agents for treating several cancer types. However, clinicians worry about PAD chemotherapy and its induction of severe non-targeted organ toxicity. Compelling evidence has shown that toxicity of PAD on delicate body organs is associated with free radical generation, DNA impairment, endocrine and mitochondrial dysfunctions, oxidative inflammation, apoptosis, endoplasmic reticulum stress, and activation of regulator signaling proteins, cell cycle arrest, apoptosis, and pathways. The emerging trend is the repurposing of FDA-approved non-anticancer drugs (FNDs) for combating the side effects toxicity of PADs. Thus, this review chronicled the mechanistic preventive and therapeutic effects of FNDs against PAD organ toxicity in preclinical studies. FNDs are potential clinical drugs for the modulation of toxicity complications associated with PAD chemotherapy. Therefore, FNDs may be suggested as non-natural agent inhibitors of unpalatable side effects of PADs.

Chemotherapy-induced toxicity in patients with testicular germ cell tumors: The impact of physical fitness and regular exercise

BACKGROUND

Testicular germ cell tumors (TGCTs) represent ∼95% of testicular malignancies and are the most common type of malignancy in young male adults. While the incidence of TGCTs has increased during the last decades, the advances in treatment, namely introducing cisplatin into the chemotherapy regimen, have made TGCTs highly curable with the 10-year survival rate exceeding 95%. However, in parallel with increased cure rates, survivors may experience acute and late adverse effects of treatment, which increase morbidity, reduce the quality of life, and can be potentially life-threatening. Chemotherapy-related toxicities include cardiovascular and metabolic diseases, secondary cancer, avascular necrosis, cognitive impairment, cancer-related fatigue, poor mental health-related quality of life, nephrotoxicity, hypogonadism, neurotoxicity, pulmonary toxicity, anxiety, and depression. These treatment-related adverse effects have emerged as important survivorship dilemmas in TGCT cancer survivors. Recently, regular physical exercise has increasingly attracted research and clinical attention as an adjunct therapy for cancer patients.

PURPOSE

Herein, we review the most common chemotherapy-related adverse effects in TGCT survivors and clinical relevance of exercise and increased cardio-respiratory fitness in modulating chemotherapy-related toxicity and quality of life in this population.

RESULTS AND CONCLUSION

Exercise has positive effects on a spectrum of physical and psychosocial outcomes during and after cancer treatment, and current guidelines on exercise prescription in chronic diseases define the recommended dose (volume and intensity) of regular exercise for cancer survivors, highlighting regular, sufficiently intensive physical activity as an essential part of patients' care.

Tranilast abrogates cisplatin-induced testicular and epididymal injuries: An insight into its modulatory impact on apoptosis/proliferation

Cisplatin is a chemotherapeutic agent whose therapeutic use is greatly limited by the associated organs' toxicity and particularly, testicular toxicity. Cisplatin-induced testicular damage reported being mediated through mitochondria-mediated apoptosis, inflammation, and oxidative stress. Evidence showed that tranilast (TRN) has the ability to restore the oxidative status and modulate TRAIL/caspase-8 signaling. This led us to hypothesize that TRN could abrogate cisplatin-induced testicular and epididymal injuries via inhibiting oxidative stress and modulating proliferation and TRAIL/caspase-8/cJNK signaling. Cisplatin injection induced oligospermia and abnormalities in testicular and epididymal structure along with impaired oxidative status. TRN administration (100 or 300 mg/kg) for 7 days post-cisplatin injection preserved spermatogenesis and restored testicular and epididymal architecture, but restoration was more so in TRN300 than TRN100. This was in line with the restoration of balanced oxidative status as indicated by the increased total antioxidant capacity, glutathione and superoxide dismutase activity, and the decreased malondialdehyde content in testes (p < 0.05 vs. cisplatin). TRN increased the cell proliferation revealed by the increased expression of proliferating cell nuclear antigen in a dose-dependent manner (p < 0.05 vs. cisplatin) whereas only TRN300 decreased testicular cJNK, TRAIL, and caspase-8 expression (p < 0.05 vs. cisplatin). Moreover, TRN dose-dependently inhibited the pro-inflammatory transcription factor NF-kB and the cytokine TNF-α expressions in testes. In conclusion, TRN300 was more effective than TRN100 in alleviating cisplatin-induced testicular and epididymal injuries and in enhancing spermatogenesis. This curative effect of TRN might be mediated through its antioxidant and anti-inflammatory impacts along with its modulatory impact on cJNK/TRAIL/caspase-8 signaling favoring proliferation rather than apoptosis.

Treatment of clinical stage I non-seminoma

Germ cell cancers are the most common solid tumors among men between 15 and 40 years. Non-seminomatous germ cell tumors (NSGCTs) represent a unique and exclusive cohort of germ cell tumor patients. Non-seminoma can harbor different histologic components. The most commonly found histologies are embryonal cell cancer, teratoma, yolk sack tumor and choriocarcinoma, as well as teratocarcinoma and seminoma, in combination with non-seminomatous germ cell tumors histologic types. The clinical definition of stage I non-seminoma is the absence of metastatic lesions on imaging and normal tumor markers. The cure rate for clinical stage I NSGCT is 99% and this can be achieved by three therapeutic strategies: Active surveillance with treatment at the time of relapse, retroperitoneal lymph node dissection or adjuvant chemotherapy. The balancing of these various strategies should always be based on an individual risk profile of NGSCG patient depending on the lymphovascular invasion of the tumor.

Protective Effects of Nucleosides-Rich Extract from Cordyceps cicadae against Cisplatin Induced Testicular Damage

Cisplatin (CISP) is an efficacious anticancer agent used in chemotherapy, however, the constraint to its clinical utility is the stray organ toxicity including testicular damage linked to oxidative and inflammatory cascades. This study aimed to explore the protective effect of nucleosides-rich extract from Cordyceps cicadae (NRCE) against CISP-induced testicular damage in rats. Rats were subjected to prophylactic oral administration of NRCE (50, 100 and 400 mg/kg body weight/day) for 7 days prior to testicular toxicity induced by CISP (10 mg/kg, ip) and were sacrificed after 72 h post-CISP injection. Cisplatin caused significant deficits in sperm count, viability and motility, testosterone and follicle stimulating hormone (FSH) compared to normal control. It depressed testicular activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), total antioxidant content (TAC), whereas malondialdehyde (MDA) increased remarkably. CISP considerably increased tumor necrosis factor-alpha (TNF-α) and interleukin-one beta (IL-1β) with alterations in testis histology compared to normal control. Interestingly, NRCE pretreatment inhibited the CISP-induced alterations in reproductive indices, restored the antioxidant activities in testes as well as inflammatory mediators and histology comparable to control. Our findings demonstrate that NRCE could prevent CISP testicular damage via inhibition of oxidative stress and pro-inflammation in rats.

Mechanistic perspective of protective effects of nilotinib against cisplatin-induced testicular injury in rats: Role of JNK/caspase-3 signaling inhibition

Cisplatin is an effective anticancer used widely in treatment of solid and germ cell tumors, however, the immense toxicity on healthy tissues discourages cisplatin use in prolonged treatment protocols. Testicular toxicity is amongst its undesired adverse effects. Nilotinib is a second generation multityrosine kinase inhibitor which is used as an anticancer agent with anti-inflammatory and antioxidant activities. In the present study, a single dose of cisplatin (7 mg/kg, I.P) to rats induced a significant testicular injury. Daily administration of nilotinib (20 mg/kg, orally) 24 h post cisplatin injection for 10 days ameliorated testicular damage. Nilotinib significantly increased serum testosterone and sperm concentration outside frame of oligospermia with simultaneous full recovery of sperm viability. Nevertheless, biomarkers of apoptosis such as JNKs and Caspase -3, were significantly reduced. Moreover, improved antioxidant status of the testes was inferred by significant elevation of GSR, SOD and TAC alongside with reduction in lipid peroxidation biomarkers; MDA and 4-HNE. Flow Cytometry analysis of the cell cycle confirmed a significant increase in the percentage of testicular cells present in G2/M phase and a significant decrease in the percentage of apoptotic testicular cells after nilotinib administration. Histopathologically, nilotinib preserved testicular architecture showing significant numbers of sperm and spermatids within lumens of seminiferous tubule. Furthermore, nilotinib enhanced testicular expression of Ki67 significantly, providing evidence of testicular regeneration. In conclusion, nilotinib refinement of cisplatin induced testicular toxicity is attributed to enhancing antioxidant capabilities, decreasing apoptotic signals and restoring regenerative capacity of testes suggesting nilotinib to be used in conjunction with cisplatin in treatment protocols to avoid cisplatin induced long term testicular toxicity.

Chlorella sorokiniana Extract Prevents Cisplatin-Induced Myelotoxicity In Vitro and In Vivo

Cisplatin chemotherapy causes myelosuppression and often limits treatment duration and dose escalation in patients. Novel approaches to circumvent or lessen myelotoxicity may improve clinical outcome and quality of life in these patients. Chlorella sorokiniana (CS) is a freshwater unicellular green alga and exhibits encouraging efficacy in immunomodulation and anticancer in preclinical studies. However, the efficacy of CS on chemoprotection remains unclear. We report here, for the first time, that CS extract (CSE) could protect normal myeloid cells and PBMCs from cisplatin toxicity. Also, cisplatin-induced apoptosis in HL-60 cells was rescued through reservation of mitochondrial function, inhibition of cytochrome c release to cytosol, and suppression of caspase and PARP activation. Intriguingly, cotreatment of CSE attenuated cisplatin-evoked hypocellularity of bone marrow in mice. Furthermore, we observed the enhancement of CSF-GM activity in bone marrow and spleen in mice administered CSE and cisplatin, along with increased CD11b levels in spleen. In conclusion, we uncovered a novel mechanism of CSE on myeloprotection, whereby potentially supports the use of CSE as a chemoprotector against cisplatin-induced bone marrow toxicity. Further clinical investigation of CSE in combination with cisplatin is warranted.

Doxorubicin and cisplatin induced cognitive impairment: The possible mechanisms and interventions

Chemotherapy has significantly increased the number of cancer survivors. However, chemotherapy itself carries various adverse effects that limit the efficacy of treatment and quality of life of the cancer patients. Most patients who have received chemotherapy report some cognitive deficit characterized by dysfunction in memory, learning, concentration, and reasoning. The phenomenon of cognitive decline developed from chemotherapy treatment is referred to as chemotherapy-induced cognitive impairment (CICI) or chemobrain. The two most common cancers occurring worldwide are lung and breast cancer. The predominant chemotherapeutic drugs used to treat lung and breast cancer are doxorubicin and cisplatin. There is evidence to suggest that both drugs potentially induce chemobrain. The evidence around the proposed pathogenesis of chemobrain caused by these two drugs is inconsistent. Understanding the underlying mechanisms involved in the development of chemobrain would aid in the prevention or treatment of the adverse effects of chemotherapy on brain. This review will summarize and discuss controversial findings and possible mechanisms involved in the development of chemobrain and the interventions which could limit it from in vitro, in vivo, and clinical studies.

Chemotherapy accelerates age-related development of tauopathy and results in loss of synaptic integrity and cognitive impairment

Cancer and its treatment are associated with neurotoxic side effects, including cognitive dysfunction, altered functional connectivity in the brain and structural abnormalities in white matter. There is evidence that cancer and its treatment can accelerate aging. Tau is a microtubule associated protein that contributes to microtubule stability thereby playing a key role in neuronal function. Clustering of tau is commonly observed in the aged brain and is related to cognitive decline. We hypothesized that chemotherapy-induced cognitive impairment is associated with accelerated development of tau clustering in the brain as a sign of accelerated aging. We show for the first time that treatment of adult (7-8 month-old) male C57BL/6 mice with cisplatin results in reduced cognitive function and a marked increase in the number of large endogenous tau clusters in the hippocampus when assessed 4 months later. In contrast, we detected only few small tau clusters in the hippocampus of age-matched 11-12 month-old control mice. Astrocyte GFAP expression was increased in close vicinity to the tau clusters in cisplatin-treated mice. We did not detect changes in the microglial marker Iba-1 in the brain of mice treated with cisplatin. The accelerated formation of Tau-1 clusters in cisplatin-treated mice was associated with a decrease in the levels of the post-synaptic marker PSD95 and of the presynaptic marker synaptophysin in the hippocampus. We demonstrate here for the first time that chemotherapy markedly accelerates development of signs of tauopathy and loss of synaptic integrity in the hippocampus. These findings provide a mechanistic link between chemotherapy cognitive decline and accelerated aging in cancer survivors.

Protective effect of mirtazapine versus ginger against cisplatin-induced testicular damage in adult male albino rats

Cisplatin (CP) is a chemotherapy medication used to treat different types of organs cancers. It has damaging effects on testes. Mirtazapine is an antidepressant, which is used primarily in the treatment of depression and other anxiety disorders. Ginger is a naturally growing plant with antioxidant properties. Thirty-six adult male albino rats, subdivided into six groups (six animals each) received treatment for 30 days. Group I (control) received saline solution orally; group II received mirtazapine (20 mg/kg). Group III received ginger (200 mg/kg/day), group IV received CP (7 mg/kg) IP single dose, at day 23rd, group V received mirtazapine (200 mg/day) orally till day 23rd, CP (7 mg/kg) IP at day 23rd, mirtazapine till day 30th, group VI received ginger (200 mg/Kg/day) orally till day 23rd, CP (7 mg/kg) IP at day 23rd, and then ginger at the previous dose till day 30th. This study examined the microscopic changes associated with CP and the possible testicular protective role of mirtazapine versus ginger of adult male rats. Mirtazapine and ginger resulted in cellular protection of testicular tissue as evident from microscopic changes including Sertoli cells, spermatogonia, and Leydig cells. Ginger showed to have a more protective effect than mirtazapine on testicular tissue against CP treatment.

Cisplatin treatment induces attention deficits and impairs synaptic integrity in the prefrontal cortex in mice

Patients treated for cancer frequently experience chemobrain, characterized by impaired memory and reduced attention. These deficits often persist after treatment, and no preventive or curative interventions exist. In mice, we assessed the effect of cisplatin chemotherapy on attention using the 5-choice serial reaction time task and on synaptic integrity. We also assessed the capacity of mesenchymal stem cells to normalize the characteristics of chemobrain. Mice were trained in the 5-choice serial reaction time task. After reaching advancement criteria at a 4-second stimulus time, they were treated with cisplatin followed by nasal administration of mesenchymal stem cells. Cisplatin reduced the percentage of correct responses due to an increase in omissions, indicating attention deficits. Mesenchymal stem cell treatment reversed these cisplatin-induced deficits in attention. Cisplatin also induced abnormalities in markers of synaptic integrity in the prefrontal cortex. Specifically, cisplatin decreased expression of the global presynaptic marker synaptophysin and the glutamatergic presynaptic marker vGlut2. Expression of the presynaptic GABAergic marker vGAT increased. Nasal mesenchymal stem cell administration normalized these markers of synaptic integrity. In conclusion, cisplatin induces long-lasting attention deficits that are associated with decreased synaptic integrity in the prefrontal cortex. Nasal administration of mesenchymal stem cells reversed these behavioural and structural deficits.

Testicular Cancer Biomarkers: A Role for Precision Medicine in Testicular Cancer

Testicular germ cell tumors (TGCTs) represent the most common solid tumors among men aged 15 to 34 years. Fortunately, recent advances have made testicular cancer a highly curable disease. Despite the high cure rates, there are still several areas in testis cancer care where treatment decisions are controversial and guided only with clinical factors and historic serum tumor markers. Unfortunately, unlike other genitourinary malignancies, modern research techniques have not been widely tested or applied to germ cell tumors, perhaps as a result of excellent prognosis in this cohort of young men. Despite this, there remain numerous challenges and pitfalls in testis cancer care that need to be addressed. A reliable set of biomarkers could be extremely useful in helping risk-stratify patients, detect relapse early, guide surgical decision-making, and tailor follow-up. Current tumor markers (Alpha-fetoprotein, human chorionic gonadotrophin, and lactate dehydrogenase) have low accuracy and low sensitivity when used not only as diagnostic but also as prognostic and predictive markers. In twenty-first century medicine, there is a role for further prognostic stratification and the development of novel biomarkers that offer greater sensitivity and specificity for TGCTs. Despite the initial promising results, the majority of preclinical biomarkers do not, as yet have a proven validated role in clinical practice, and future prospective trials are needed to support and confirm the results of cohort studies. In this narrative review, we aimed to highlight the recent innovations in the development and implementation of novel testicular tumor markers and discuss their clinical applications and limitations in the management of this disease.

Evaluation of the Effect of Pentoxifylline on Cisplatin-Induced Testicular Toxicity in Rats

Chemotherapy is associated with male infertility. Cisplatin (cis-diamminedichloro-platinum (II) (CDDP) as a chemotherapy medication used to treat a number of cancers has been reported to most likely induce testicular toxicity. Administration of antioxidants, such as pentoxifylline (PTX) may reduce some Adverse Drug Reactions (ADRs) of CDDP. Therefore, this study investigated the potentially protective effects of PTX on CDDP-induced testicular toxicity in adult male rats. For this purpose, 42 male rats were randomly divided into 7 groups. The rats were orally pretreated with PTX at the 3 doses of 75, 150, and 300 mg/kg once a day for 14 successive days. On the 14^th day of the study, they were intraperitoneally (IP) administered with a single dose of CDDP (7 mg/kg). Finally, the sperm/testis parameters, serum levels of reproductive hormones, including testosterone, Luteinizing Hormone (LH), and Follicle Stimulating Hormone (FSH) as the pivotal endocrine factors controlling testicular functions, and histopathological changes of testis tissue were examined. Pretreatment with the two doses of 75 and 150 mg/kg PTX indicated significant increases in the sperm count and motility induced by CDDP administration. The right and significantly left testis weights were decreased following the treatment with 300 mg/kg of PTX plus CDDP. However, 75 mg/kg of PTX plus CDDP showed the best near-to-normal histopathological features. The results demonstrated that PTX alone enhanced some parameters, such as the sperm count, while reducing other parameters, including sperm fast motility and germ layer thickness. Furthermore, despite testosterone or LH levels, the mean serum FSH level was significantly augmented by the doses of 75 and 150 mg/kg. It was concluded that PTX administration cannot reduce CDDP-induced testicular toxicity even at high doses (e.g., 300 mg/kg), while it seemed to partially intensify CDDP toxicity effects at a dose of 75 mg/kg. Thus, further research is required in this regard.

Lysine methylation represses p53 activity in teratocarcinoma cancer cells

TP53 (which encodes the p53 protein) is the most frequently mutated gene among all human cancers, whereas tumors that retain the wild-type TP53 gene often use alternative mechanisms to repress the p53 tumor-suppressive function. Testicular teratocarcinoma cells rarely contain mutations in TP53, yet the transcriptional activity of wild-type p53 is compromised, despite its high expression level. Here we report that in the teratocarcinoma cell line NTera2, p53 is subject to lysine methylation at its carboxyl terminus, which has been shown to repress p53's transcriptional activity. We show that reduction of the cognate methyltransferases reactivates p53 and promotes differentiation of the NTera2 cells. Furthermore, reconstitution of methylation-deficient p53 mutants into p53-depleted NTera2 cells results in elevated expression of p53 downstream targets and precocious loss of pluripotent gene expression compared with re-expression of wild-type p53. Our results provide evidence that lysine methylation of endogenous wild-type p53 represses its activity in cancer cells and suggest new therapeutic possibilities of targeting testicular teratocarcinoma.

TDRG1 regulates chemosensitivity of seminoma TCam-2 cells to cisplatin via PI3K/Akt/mTOR signaling pathway and mitochondria-mediated apoptotic pathway

We previously identified TDRG1 (testis developmental related gene 1), a novel gene with exclusive expression in testis, promoted the proliferation and progression of cultured human seminoma cells through PI3K/Akt/mTOR signaling. As increasing evidence reveal that aberrant activation of this signaling is involved in cisplatin resistance. Then, in this study, we further explored whether TDRG1 regulated the chemosensitivity of seminoma TCam-2 cells to cisplatin. Our researches showed TDRG1 could regulate the viability of TCam-2 cells following cisplatin treatment in vitro through control of both cell apoptosis and cell cycle. Mechanistically, we observed TDRG1 positively regulated the expression levels of the key elements in PI3K/Akt/mTOR pathway including p-PI3K, p-Akt and p-mTOR and also affected the translocation of nuclear p-Akt in TCam-2 cells during cisplatin treatment. Meanwhile, the levels of Bad, cytochrome c, caspase-9 ratio (activated/total), caspase-3 ratio (activated/total) and cleaved-PARP were negatively modulated by TDRG1, which meant the involvement of mitochondria-mediated apoptotic pathway. Furthermore, we found the effect of TDRG1 knockdown or TDRG1 overexpression could be reversed by IGF-1, a PI3K signaling activator, or LY294002, a inhibitor of this pathway, respectively. Similar effects of TDRG1 on cisplatin chemosensitivity and associated molecular mechanism were also confirmed in vivo by employing xenograft assays. In addition, the positive correlation between TDRG1 and p-PI3K, or p-Akt, was found in tumor tissues from seminoma patients. In conclusion, we uncover that TDRG1 regulates chemosensitivity of TCam-2 cells to cisplatin through PI3K/Akt/mTOR signaling and mitochondria-mediated apoptotic pathway both in vitro and in vivo.

Metformin Prevents Cisplatin-Induced Cognitive Impairment and Brain Damage in Mice

Rationale

Chemotherapy-induced cognitive impairment, also known as ‘chemobrain’, is now widely recognized as a frequent adverse side effect of cancer treatment that often persists into survivorship. There are no drugs available to prevent or treat chemotherapy-induced cognitive deficits. The aim of this study was to establish a mouse model of cisplatin-induced cognitive deficits and to determine the potential preventive effects of the anti-diabetic drug metformin.

Results

Treatment of C57/BL6J mice with cisplatin (cumulative dose 34.5mg/kg) impaired performance in the novel object and place recognition task as well as in the social discrimination task indicating cognitive deficits. Co-administration of metformin prevented these cisplatin-induced cognitive impairments. At the structural level, we demonstrate that cisplatin reduces coherency of white matter fibers in the cingulate cortex. Moreover, the number of dendritic spines and neuronal arborizations as quantified on Golgi-stained brains was reduced after cisplatin treatment. Co-administration of metformin prevented all of these structural abnormalities in cisplatin-treated mice. In contrast to what has been reported in other models of chemobrain, we do not have evidence for persistent microglial or astrocyte activation in the brains of cisplatin-treated mice. Finally, we show that co-administration of metformin also protects against cisplatin-induced peripheral neuropathy.

Conclusion

In summary, we show here for the first time that treatment of mice with cisplatin induces cognitive deficits that are associated with structural abnormalities in the brain. Moreover, we present the first evidence that the widely used and safe anti-diabetic drug metformin protects against these deleterious effects of cancer treatment. In view of the ongoing clinical trials to examine the potential efficacy of metformin as add-on therapy in patients treated for cancer, these findings should allow rapid clinical translation.

Changes in the expression profiles of claudins during gonocyte differentiation and in seminomas

Testicular germ cell tumors (TGCTs) are the most common type of cancer in young men and their incidence has been steadily increasing for the past decades. TGCTs and their precursor carcinoma in situ (CIS) are thought to arise from the deficient differentiation of gonocytes, precursors of spermatogonial stem cells. However, the mechanisms relating failed gonocyte differentiation to CIS formation remain unknown. The goal of this study was to uncover genes regulated during gonocyte development that would show abnormal patterns of expression in testicular tumors, as prospective links between failed gonocyte development and TGCT. To identify common gene and protein signatures between gonocytes and seminomas, we first performed gene expression analyses of transitional rat gonocytes, spermatogonia, human normal testicular, and TGCT specimens. Gene expression arrays, pathway analysis, and quantitative real-time PCR analysis identified cell adhesion molecules as a functional gene category including genes downregulated during gonocyte differentiation and highly expressed in seminomas. In particular, the mRNA and protein expressions of claudins 6 and 7 were found to decrease during gonocyte transition to spermatogonia, and to be abnormally elevated in seminomas. The dynamic changes in these genes suggest that they may play important physiological roles during gonocyte development. Moreover, our findings support the idea that TGCTs arise from a disruption of gonocyte differentiation, and position claudins as interesting genes to further study in relation to testicular cancer.

Prospectively Identified Incident Testicular Cancer Risk in a Familial Testicular Cancer Cohort

BACKGROUND

Human testicular germ cell tumors (TGCT) have a strong genetic component and a high familial relative risk. However, linkage analyses have not identified a rare, highly penetrant familial TGCT (FTGCT) susceptibility locus. Currently, multiple low-penetrance genes are hypothesized to underlie the familial multiple-case phenotype. The observation that two is the most common number of affected individuals per family presents an impediment to FTGCT gene discovery. Clinically, the prospective TGCT risk in the multiple-case family context is unknown.

METHODS

We performed a prospective analysis of TGCT incidence in a cohort of multiple-affected-person families and sporadic-bilateral-case families; 1,260 men from 140 families (10,207 person-years of follow-up) met our inclusion criteria. Age-, gender-, and calendar time-specific standardized incidence ratios (SIR) for TGCT relative to the general population were calculated using SEER*Stat.

RESULTS

Eight incident TGCTs occurred during prospective FTGCT cohort follow-up (versus 0.67 expected; SIR = 11.9; 95% CI, 5.1-23.4; excess absolute risk = 7.2/10,000). We demonstrate that the incidence rate of TGCT is greater among bloodline male relatives from multiple-case testicular cancer families than that expected in the general population, a pattern characteristic of adult-onset Mendelian cancer susceptibility disorders. Two of these incident TGCTs occurred in relatives of sporadic-bilateral cases (0.15 expected; SIR = 13.4; 95% CI, 1.6-48.6).

CONCLUSIONS

Our data are the first to indicate that despite relatively low numbers of affected individuals per family, members of both multiple-affected-person FTGCT families and sporadic-bilateral TGCT families comprise high-risk groups for incident testicular cancer.

IMPACT

Men at high TGCT risk might benefit from tailored risk stratification and surveillance strategies.

Mechanical stress promotes cisplatin-induced hepatocellular carcinoma cell death

Cisplatin (CisPt) is a commonly used platinum-based chemotherapeutic agent. Its efficacy is limited due to drug resistance and multiple side effects, thereby warranting a new approach to improving the pharmacological effect of CisPt. A newly developed mathematical hypothesis suggested that mechanical loading, when coupled with a chemotherapeutic drug such as CisPt and immune cells, would boost tumor cell death. The current study investigated the aforementioned mathematical hypothesis by exposing human hepatocellular liver carcinoma (HepG2) cells to CisPt, peripheral blood mononuclear cells, and mechanical stress individually and in combination. HepG2 cells were also treated with a mixture of CisPt and carnosine with and without mechanical stress to examine one possible mechanism employed by mechanical stress to enhance CisPt effects. Carnosine is a dipeptide that reportedly sequesters platinum-based drugs away from their pharmacological target-site. Mechanical stress was achieved using an orbital shaker that produced 300 rpm with a horizontal circular motion. Our results demonstrated that mechanical stress promoted CisPt-induced death of HepG2 cells (~35% more cell death). Moreover, results showed that CisPt-induced death was compromised when CisPt was left to mix with carnosine 24 hours preceding treatment. Mechanical stress, however, ameliorated cell death (20% more cell death).

Fish oil, contained in eicosapentaenoic acid and docosahexaenoic acid, attenuates testicular and spermatological damage induced by cisplatin in rats

The aim of this study was to investigate the beneficial effects of the fish oil (FO) supplementation on oxidative stress, sperm characteristics and histological alterations in the male reproductive system of rats against cisplatin (CP) toxicity. The rats were divided randomly into 4 equal groups (control, FO, CP and FO + CP). FO was orally administered at the dose of 1 softgel per rat per day for 14 days and CP was intraperitoneally given at the dose of 7 mg kg(-1) with a single injection. In CP + FO group, they were applicated at the same doses and times. The results showed that CP caused a significant oxidative damage via induction of lipid peroxidation and reduction in the antioxidant defence system potency in the testis tissue. In addition, sperm motility and sperm concentration significantly decreased but the abnormal sperm rate and histopathological testicular damage increased with CP treatment. On the other hand, FO treatment prevented oxidative, histopathological and spermatological effects of CP and reversed side effects of CP. In conclusion, FO supplementation had significant beneficial effects against CP toxicity on male reproductive system and toxic effects of CP can be prevented by FO treatment. Therefore, it appears that fish oil may be useful for the prevention and treatment of cisplatin-induced reproductive system toxicity.

Impact of treatment exposures on cardiovascular risk and insulin resistance in childhood cancer survivors

BACKGROUND

Childhood cancer survivors (CCS) are more insulin resistant and have higher levels of several cardiovascular risk factors even while still children. This study examines specific treatment exposures associated with cardiovascular risk factors and insulin resistance.

METHODS

CCS of ages 9 to 18 years at study entry and in remission 5 years or more from diagnosis (n = 319) and 208 sibling controls were recruited into this cross-sectional study that included physiologic assessment of insulin resistance (hyperinsulinemic euglycemic clamp) and assessment of cardiovascular risk factors. Regression and recursive tree modeling were used to ascertain treatment combinations associated with insulin resistance and cardiovascular risk.

RESULTS

Mean current age of CCS was 14.5 years and 54% were male (siblings 13.6 years, 54% male). Diagnoses included leukemia (35%), brain tumors (36%), solid tumors (33%), or lymphoma (6%). Among CCS, analysis of individual chemotherapy agents failed to find associations with cardiovascular risk factors or insulin resistance. Compared with siblings, insulin resistance was significantly higher in CCS who received platinum plus cranial radiotherapy (CRT, 92% brain tumors) and in those who received steroids but no platinum (majority leukemia). Insulin resistance did not differ between CCS who received surgery alone versus siblings. Within survivor comparisons failed to elucidate treatment combinations that increased insulin resistance compared with those who received surgery only.

CONCLUSIONS

Exposure to platinum, CRT, or steroids is associated with insulin resistance and cardiovascular risk factors and should be taken into consideration in the development of screening recommendations for cardiovascular risk.

IMPACT

Earlier identification of CCS who may benefit from targeted prevention efforts may reduce their future risk of cardiovascular disease.

Selective GPER activation decreases proliferation and activates apoptosis in tumor Leydig cells

We have previously shown that estrogens binding to estrogen receptor (ER) α increase proliferation of Leydig tumor cells. Estrogens can also bind to G protein-coupled ER (GPER) and activation of this receptor can either increase or decrease cell proliferation of several tumor types. The aim of this study was to investigate GPER expression in R2C rat tumor Leydig cells, evaluate effects of its activation on Leydig tumor cell proliferation and define the molecular mechanisms triggered in response to its activation. R2C cells express GPER and its activation, using the specific ligand G-1, is associated with decreased cell proliferation and initiation of apoptosis. Apoptosis after G-1 treatment was asserted by appearance of DNA condensation and fragmentation, decrease in Bcl-2 and increase in Bax expression, cytochrome c release, caspase and poly (ADP-ribose) polymerase-1 (PARP-1) activation. These effects were dependent on GPER activation because after silencing of the gene, using a specific small interfering RNA, cyt c release, PARP-1 activation and decrease in cell proliferation were abrogated. These events required a rapid, however, sustained extracellular regulated kinase 1/2 activation. G-1 was able to decrease the growth of R2C xenograft tumors in CD1 nude mice while increasing the number of apoptotic cells. In addition, in vivo administration of G-1 to male CD1 mice did not cause any alteration in testicular morphology, while cisplatin, the cytotoxic drug currently used for the therapy of Leydig tumors, severely damaged testicular structure, an event associated with infertility in cisplatin-treated patients. These observations indicate that GPER targeting for the therapy of Leydig cell tumor may represent a good alternative to cisplatin to preserve fertility in Leydig tumor patients.

Molecular characteristics of malignant ovarian germ cell tumors and comparison with testicular counterparts: implications for pathogenesis

This review focuses on the molecular characteristics and development of rare malignant ovarian germ cell tumors (mOGCTs). We provide an overview of the genomic aberrations assessed by ploidy, cytogenetic banding, and comparative genomic hybridization. We summarize and discuss the transcriptome profiles of mRNA and microRNA (miRNA), and biomarkers (DNA methylation, gene mutation, individual protein expression) for each mOGCT histological subtype. Parallels between the origin of mOGCT and their male counterpart testicular GCT (TGCT) are discussed from the perspective of germ cell development, endocrinological influences, and pathogenesis, as is the GCT origin in patients with disorders of sex development. Integrated molecular profiles of the 3 main histological subtypes, dysgerminoma (DG), yolk sac tumor (YST), and immature teratoma (IT), are presented. DGs show genomic aberrations comparable to TGCT. In contrast, the genome profiles of YST and IT are different both from each other and from DG/TGCT. Differences between DG and YST are underlined by their miRNA/mRNA expression patterns, suggesting preferential involvement of the WNT/β-catenin and TGF-β/bone morphogenetic protein signaling pathways among YSTs. Characteristic protein expression patterns are observed in DG, YST and IT. We propose that mOGCT develop through different developmental pathways, including one that is likely shared with TGCT and involves insufficient sexual differentiation of the germ cell niche. The molecular features of the mOGCTs underline their similarity to pluripotent precursor cells (primordial germ cells, PGCs) and other stem cells. This similarity combined with the process of ovary development, explain why mOGCTs present so early in life, and with greater histological complexity, than most somatic solid tumors.

Protection of cisplatin-induced spermatotoxicity, DNA damage and chromatin abnormality by selenium nano-particles

Cisplatin (CIS), an anticancer alkylating agent, induces DNA adducts and effectively cross links the DNA strands and so affects spermatozoa as a male reproductive toxicant. The present study investigated the cellular/biochemical mechanisms underlying possible protective effect of selenium nano-particles (Nano-Se) as an established strong antioxidant with more bioavailability and less toxicity, on reproductive toxicity of CIS by assessment of sperm characteristics, sperm DNA integrity, chromatin quality and spermatogenic disorders. To determine the role of oxidative stress (OS) in the pathogenesis of CIS gonadotoxicity, the level of lipid peroxidation (LPO), antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) and peroxynitrite (ONOO) as a marker of nitrosative stress (NS) and testosterone (T) concentration as a biomarker of testicular function were measured in the blood and testes. Thirty-two male Wistar rats were equally divided into four groups. A single IP dose of CIS (7 mg/kg) and protective dose of Nano-Se (2 mg/kg/day) were administered alone or in combination. The CIS-exposed rats showed a significant increase in testicular and serum LPO and ONOO level, along with a significant decrease in enzymatic antioxidants levels, diminished serum T concentration and abnormal histologic findings with impaired sperm quality associated with increased DNA damage and decreased chromatin quality. Coadministration of Nano-Se significantly improved the serum T, sperm quality, and spermatogenesis and reduced CIS-induced free radical toxic stress and spermatic DNA damage. In conclusion, the current study demonstrated that Nano-Se may be useful to prevent CIS-induced gonadotoxicity through its antioxidant potential.

Probability of metachronous testicular cancer in patients with biopsy-proven intratubular germ cell neoplasia depends on first-time treatment of germ cell cancer

PURPOSE

To evaluate the probability of subsequent testicular cancer (STC) in patients with intratubular germ cell neoplasia unclassified (IGCNU) treated for first-time invasive germ cell cancer.

PATIENTS AND METHODS

Sixty-one patients with germ cell testicular cancer or extragonadal germ cell cancer received follow-up from diagnosis of IGCNU to development of STC, initiation of IGCNU-definitive treatment (orchiectomy/radiotherapy), emigration, death, or end of follow-up. The probability of STC was assessed in subgroups according to chemotherapy burden.

RESULTS

The probability of STC in the nonexposed patients was significantly increased compared with those exposed to chemotherapy (P = .05; 5-year probability of 54% [95% CI, 33% to 78%] and 23% [95% CI, 11% to 45%], respectively). In the group of patients treated with one to three cycles or no chemotherapy, the probability of STC was significantly increased compared with those exposed to four or more cycles (P = .03; 5-year probability of 42% [95% CI, 27% to 62%] and 22% [95% CI, 8% to 54%], respectively). Twenty-two of 22 patients were tumor-free and alive at a median of 56 months (range, 2 to 184 months) after diagnosis of STC.

CONCLUSION

Platinum-based chemotherapy may reduce the probability of STC in patients with IGCNU, particularly in those treated with four or more cycles of chemotherapy. A watch-and-wait strategy for patients with IGCNU may be justified in selected patients with future plans for paternity.

Population-based case-control study of recreational drug use and testis cancer risk confirms an association between marijuana use and nonseminoma risk

BACKGROUND

Testicular germ cell tumor (TGCT) incidence increased steadily in recent decades, but causes remain elusive. Germ cell function may be influenced by cannabinoids, and 2 prior epidemiologic studies reported that the use of marijuana may be associated with nonseminomatous TGCT. Here, the authors evaluate the relation between TGCTs and exposure to marijuana and other recreational drugs using a population-based case-control study.

METHODS

In total, 163 patients who were diagnosed with TGCT in Los Angeles County from December 1986 to April 1991 were enrolled, and 292 controls were matched on age, race/ethnicity, and neighborhood. Participants were asked about drug use by a structured, in-person interview. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression analysis adjusted for history of cryptorchidism; education; religiosity; and reported use of marijuana, cocaine, and amyl nitrite.

RESULTS

Compared with never use, ever use of marijuana had a 2-fold increased risk (OR, 1.94; 95% CI, 1.02-3.68), whereas ever use of cocaine had a negative association with TGCT (OR, 0.54; 95% CI, 0.32-0.91). Stratification on tumor histology revealed a specific association of marijuana use with nonseminoma and mixed histology tumors (OR, 2.42; 95% CI, 1.08-5.42).

CONCLUSIONS

A specific association was observed between marijuana use and the risk of nonseminoma and mixed tumors. To the authors' knowledge, this is the first report of a negative association between cocaine use and TGCT risk. The current results warrant mechanistic studies of marijuana's effect on the endocannabinoid system and TGCT risk and caution that recreational and therapeutic use of cannabinoids by young men may confer malignant potential to testicular germ cells.

Chemotherapy refractory testicular germ cell tumor is associated with a variant in Armadillo Repeat gene deleted in Velco-Cardio-Facial syndrome (ARVCF)

INTRODUCTION

There is evidence that inherited genetic variation affects both testicular germ cell tumor (TGCT) treatment outcome and risks of late-complications arising from cisplatin-based chemotherapy. Using a candidate gene approach, we examined associations of three genes involved in the cisplatin metabolism pathway, GSTP1, COMT, and TPMT, with TGCT outcome and cisplatin-induced neurotoxicity.

MATERIALS AND METHODS

Our study population includes a subset of patients (n = 137) from a genome-wide association study at the University of Pennsylvania that evaluates inherited genetic susceptibility to TGCT. All patients in our study had at least one course of cisplatin-based chemotherapy with at least 1 year of follow-up. A total of 90 markers in GSTP1, COMT, and TPMT and their adjacent genomic regions (±20 kb) were analyzed for associations with refractory TGCT after first course of chemotherapy, progression-free survival (PFS), overall survival (OS), peripheral neuropathy, and ototoxicity.

RESULTS

After adjustment for multiple comparisons, one Single nucleotide polymorphism (SNP), rs2073743, in the flanking region (±20 kb) of COMT was associated with refractory TGCT after initial chemotherapy. This SNP lies within the intron region of the Armadillo Repeat gene deleted in Velco-Cardio-Facial syndrome (ARVCF). The G allele of rs2073743 predisposed patients to refractory disease with a relative risk of 2.6 (95% CI 1.1, 6.3; P = 0.03). Assuming recessive inheritance, patients with the GG genotype had 22.7 times higher risk (95% CI 3.3, 155.8; P = 0.04) of developing refractory disease when compared to those with the GC or CC genotypes. We found no association of our candidate genes with peripheral neuropathy, ototoxicity, PFS and OS.

DISCUSSION

This is the first study to suggest that germline genetic variants of ARVCF may affect TGCT outcome. The result of this study is hypothesis generating and should be validated in future studies.