Semen quality in non-Hodgkin lymphoma survivors: a monocentric retrospective study.

STUDY QUESTION: How is semen quality affected by treatment in survivors of non-Hodgkin lymphoma (NHL)? SUMMARY ANSWER: Before cancer treatment, most NHL subjects were normozoospermic and, while standard first-line treatments seemed compatible with post-treatment recovery after 18 months, salvage therapy followed by haematopoietic stem cell transplant caused permanent damage to spermatogenesis in many cases, with 66% azoospermic subjects in the long term. WHAT IS KNOWN ALREADY: Testicular function has been widely investigated in relation to the most common malignancies in men of reproductive age, such as testicular cancer and Hodgkin lymphoma, but NHL has been somewhat under-investigated. The available reports generally show a post-treatment worsening of semen parameters in NHL survivors, but they involved small caseloads or a subgroup of broader caseloads, and their results are not comparable. STUDY DESIGN, SIZE, DURATION: We conducted a retrospective analysis of 222 subjects who attended our University Hospital Sperm Bank between 2002 and 2017 for sperm cryopreservation after a diagnosis of NHL. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study included 222 patients with NHL who underwent sperm cryopreservation before any antineoplastic treatment. Subjects with any comorbidity and/or other conditions interfering with sperm parameters were excluded. All patients underwent a careful medical history and physical examination at the time of sperm cryopreservation (T0) and had at least one follow-up visit at 6 (T6), 12 (T12), 18 (T18) and/or 24 months (T24) or more than 24 months (T > 24), with a median follow-up of 47.5 months (range 28-140 months). Fertility information was collected through the administration of a questionnaire. MAIN RESULTS AND THE ROLE OF CHANCE: Pre-treatment, more than 80% of NHL patients were normozoospermic and in 15.9% of cases had already fathered a child. Aggressive lymphomas were associated with worse baseline semen volume and total sperm number compared to indolent subtypes (P < 0.05). Post-treatment analyses showed that standard first-line treatments alone had a more favourable outcome than intensified regimens for semen parameters, with total sperm number returning to near-baseline values at 18 months (T0: 195.0 ± 189.8 versus T18: 113.4 ± 103.1, P = 0.278), and a 7.7% prevalence of azoospermia at 2 years. In this subgroup receiving standard first-line treatments, radiotherapy of the pelvis versus other 'high' sites (mediastinum, latero-cervical and axillary lymph nodes, etc.) was associated with an increased risk of developing post-treatment azoospermia (odds ratio 4.29, 95% CI 1.81-10.14; P = 0.001). Two-thirds of subjects who had relapsed or had disease progression after first-line treatment and then underwent salvage treatment ± haematopoietic stem cell transplant became azoospermic. Fertility data were available for 176 patients: 15.9% already had at least one child prior to the NHL diagnosis and 12.5% (22 patients) desired children after treatment. Fourteen patients achieved fatherhood: 12 through natural conception and two following ART. LIMITATIONS, REASONS FOR CAUTION: The main limitations of the study are the lack of data on blood hormones for evaluation of testicular function as a whole and the non-compliance of several patients in attending follow-up visits at all time points, resulting in a reduced sample size for the treatment subgroup analyses. Furthermore, despite a good fertility questionnaire response rate (>80%), the low number of NHL survivors actively seeking fatherhood limits the generalization of results. WIDER IMPLICATIONS OF THE FINDINGS: The increased survival of NHL patients of reproductive age makes it essential to focus on the testicular toxicity of the treatment. Sperm cryopreservation must be suggested before any treatment. Two years after first-line treatments, sperm number showed signs of recovery: this finding is of the utmost importance for oncofertility counselling, as it indicates that only a standard first-line chemotherapy in many patients may be compatible with at least a partial spermatogenesis recovery in the long term. Nonetheless, it is expected that up to 30% of subjects will require treatment intensification, which could result in permanent testicular damage; in such cases the use of banked semen might represent the patient's best chance for future fertility. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by a grant from the Italian Ministry of Education and Research (MIUR-PRIN 2015-2015XSNA83-002) and the 'Sapienza' University of Rome, Faculty of Medicine. The authors report no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Seminal plasma miRNAs in Klinefelter syndrome and in obstructive and non-obstructive azoospermia.

MicroRNAs are small, non-coding, single-strand oligonucleotides which regulate gene expression. There is little evidence in the literature about their role in azoospermia and no studies have investigated their presence in the seminal plasma of men with Klinefelter syndrome. This retrospective study investigated if there were any differences in microRNA expression (miR-509-5p, miR-122-5p, miR-34b-3p, miR-34c-5p) in the seminal plasma of patients with obstructive azoospermia, non-obstructive azoospermia and Klinefelter syndrome. Hormone levels were also investigated to identify any correlations with microRNA expression. We analysed 200 subjects (40 Klinefelter syndrome, 60 non-obstructive azoospermia with a normal karyotype, 60 obstructive azoospermia and 40 who were normozoospermic). All subjects underwent semen examination. Total RNA was obtained from seminal plasma and microRNA expression was analysed by RT-qPCR. There was a significant reduction in the expression of all investigated miRNAs in the seminal plasma of all patient categories in comparison with controls. There was a weak negative correlation between FSH values and miR-509-5p expression in non-obstructive azoospermic patients (r = - 0.391; p = 0.014). We hypothesize that in non-obstructive azoospermia and Klinefelter syndrome patients, the downregulation of microRNAs may be caused by damage to the germ cells and aberrant spermatogenesis. In our opinion the identification of seminal plasma microRNAs deriving almost exclusively from the testes could be essential for the development of specific biomarkers for male infertility. The expression of such microRNAs, in combination with hormone values, could comprise testicular markers of abnormal spermatogenesis and failed mature sperm production.

Androgenetic alopecia: effects of oral finasteride on hormone profile, reproduction and sexual function.

PURPOSE: Androgenetic Alopecia (AGA) is a common non-cicatricial alopecia. AGA treatment with finasteride was reported to have sexological side effects and its induced hormonal alterations could damage spermatogenesis. Thus, in patients affected by AGA undergoing oral therapy with Finasteride 1 mg/die, we aimed to evaluate the presence of modification in sperm parameters, hormone profile and sexual function. METHODS: We retrospectively evaluated 55 male subjects aged 18-45 years with AGA who underwent systemic therapy with Finasteride 1 mg/die. Each subject underwent semen and blood hormone analysis, IIEF15 questionnaire administration at baseline (T0) at 6 (T6) and 12 (T12) months after the beginning of therapy and 1 year after treatment discontinuation (TD). RESULTS: At T6 we detected a statistically significant worsening of total sperm number (232.4 ± 160.3 vs. 133.2 ± 82.0; p = 0.01 vs. T0) and abnormal forms (79.8 ± 6.0 vs. 82.7 ± 5.7; p < 0.05 vs. T0). No difference was found for all sperm parameters at T12 and T24, except for the percentage of abnormal forms (79.8 ± 6.0 vs. 82.6 ± 4.8; p < 0.05 T24 vs. T0). Testosterone levels were increased at T0 vs. T6 (22.1 ± 7.1 vs. 28.0 ± 8.0 ng/mL; p < 0.05). No significant differences of IIEF15 questionnaire were detected across the study. CONCLUSIONS: Finasteride is associated with significant seminological and testosterone alterations, but no sexual dysfunctions were reported during treatment of these andrologically healthy subjects. Although, sperm parameters seem to return comparable to baseline after treatment discontinuation, it is advisable to perform a careful andrological evaluation before treatment.

Mechanisms of Testicular Disruption from Exposure to Bisphenol A and Phtalates.

Great attention has been paid in recent years to the harmful effects of various chemicals that interfere with our natural hormone balance, collectively known as endocrine-disrupting chemicals (EDCs) or endocrine disruptors. The effects on the reproductive system of bisphenol A (BPA) and phthalates have received particular attention: while they have a short half-life, they are so widespread that human exposure can be considered as continuous. Evidence is often limited to the animal model, disregarding the likelihood of human exposure to a mixture of contaminants. Data from animal models show that maternal exposure probably has harmful effects on the male fetus, with an increased risk of urogenital developmental abnormalities. After birth, exposure is associated with changes in the hypothalamic-pituitary-testicular axis, hindering the development and function of the male genital pathways through the mediation of inflammatory mechanisms and oxidative stress. The epidemiological and clinical evidence, while generally confirming the association between reproductive abnormalities and some phthalate esters and BPA, is more contradictory, with wildly different findings. The aim of this review is therefore to provide an update of the potential mechanisms of the damage caused by BPA and phthalates to reproductive function and a review of the clinical evidence currently available in the literature.

Cryopreservation of Sperm: Effects on Chromatin and Strategies to Prevent Them.

Cryopreservation is a technique that can keep sperm alive indefinitely, enabling the conservation of male fertility. It involves the cooling of semen samples and their storage at -196 °C in liquid nitrogen. At this temperature all metabolic processes are arrested. Sperm cryopreservation is of fundamental importance for patients undergoing medical or surgical treatments that could induce sterility, such as cancer patients about to undergo genotoxic chemotherapy or radiotherapy, as it offers these patients not only the hope of future fertility but also psychological support in dealing with the various stages of the treatment protocols.Despite its importance for assisted reproduction technology (ART) and its success in terms of babies born, this procedure can cause cell damage and impaired sperm function. Various studies have evaluated the impact of cryopreservation on chromatin structure, albeit with contradictory results. Some, but not all, authors found significant sperm DNA damage after cryopreservation. However, studies attempting to explain the mechanisms involved in the aetiology of cryopreservation-induced DNA damage are still limited. Some reported an increase in sperm with activated caspases after cryopreservation, while others found an increase in the percentage of oxidative DNA damage. There is still little and contradictory information on the mechanism of the generation of DNA fragmentation after cryopreservation. A number of defensive strategies against cryoinjuries have been proposed in the last decade. Most studies focused on supplementing cryoprotectant medium with various antioxidant molecules, all aimed at minimising oxidative damage and thus improving sperm recovery. Despite the promising results, identification of the ideal antioxidant treatment method is still hampered by the heterogeneity of the studies, which describe the use of different antioxidant regimens at different concentrations or in different combinations. For this reason, additional studies are needed to further investigate the use of antioxidants, individually and in combination, in the cryopreservation of human sperm, to determine the most beneficial conditions for optimal sperm recovery and preservation of fertility.

Inhibin B: are modified ranges needed for orchiectomised testicular cancer patients?

Inhibin B is a gonadal hormone that downregulates the pituitary production of follicle-stimulating hormone (FSH). In recent years, inhibin B has proved to be an excellent marker of spermatogenesis and even a predictive factor for the recovery of fertility in patients undergoing orchiectomy and antineoplastic treatments. We propose to study inhibin B levels in orchiectomised testicular cancer patients, in order to identify a minimum value representative of normal semen quality. This retrospective study evaluates hormonal and semen parameters of 290 normozoospermic patients attending the Laboratory of Seminology - Sperm Bank "Loredana Gandini" (Rome, Italy) for cryopreservation of seminal fluid following a diagnosis of testicular cancer (TC group) and 117 healthy, normozoospermic men as a control group (CTR group). The percentile distribution of gonadotropin and inhibin B values in the TC and CTR groups was analyzed. There was a statistically significant difference between the two groups in the levels of all hormones (P ≤ 0.001) and in all semen parameters (P < 0.05). About 20% of TC patients revealed inhibin B levels below the 5th percentile of CTR group, despite normozoospermia, and 31.4% had normal spermatogenesis in the presence of FSH values >95th percentile of CTR group. Orchiectomised patients for testicular cancer presented inhibin B levels lower than healthy patients, despite normozoospermia. Our study revealed the poor sensitivity of the current inhibin B reference range when applied to monorchidic patients, suggesting the need to establish more representative ranges to enable more appropriate counseling in relation to the patient's new endocrine condition.

Cytological and molecular aspects of the ageing sperm.

STUDY QUESTION: Is ageing associated with a decline in semen quality and molecular changes to human sperm? SUMMARY ANSWER: Semen quality declines with advancing age and characteristic molecular changes take place during the ageing process, including increased sperm DNA damage, altered sperm protamination and altered seminal plasma miRNA profile. WHAT IS KNOWN ALREADY: During ageing, the reproductive system is exposed to physiological changes and potentially damaging factors that may impair testicular function. Reactive oxygen species (ROS) can induce errors during DNA replication, transcription or post-transcriptional events (fragmentation, chromatin condensation abnormalities and protamine expression defects). STUDY DESIGN, SIZE, DURATION: Semen parameters from 2626 healthy men aged 20-81 years were evaluated retrospectively from those attending our University Laboratory between 2011 and 2016 for andrological screening or as part of an andrological work-up. Subjects were divided into six groups by age (20-32, 33-37, 38-40, 41-44, 45-50, 51-81 years). From these subjects, semen samples from 40 elderly men (50-81 years) and 40 young men (20-40 years) (control group), all non-smokers of normal weight, were selected for the evaluation of sperm chromatin integrity, PRM1, PRM2, TNP1 and TNP2 gene expression, and microRNA expression profile in seminal plasma. PARTICIPANTS/MATERIALS, SETTING, METHODS: Semen was analysed according to WHO 2010. Sperm DNA fragmentation (SDF) was evaluated using TUNEL assay; sperm PRM1, PRM2, TNP1 and TNP2 gene expression was evaluated by quantitative RT-PCR amplification; miRNA expression profiles were analysed by TaqMan Array Cards and validated by RT-PCR amplification. MAIN RESULTS AND THE ROLE OF CHANCE: Cytological analysis - Semen volume, progressive motility and number of progressively motile sperm were significantly lower in elderly than in younger subjects (sextiles 51-81 versus 20-32 years; P < 0.001), while the percentage of abnormal forms in these subjects was significantly higher than in the 20-32 age group (P = 0.002). Binomial logistic regression models revealed an association between age and semen parameters: age 51-81 was associated with changes in total sperm number (OR 2.47; 95% CI 1.52-4.02; P < 0.001), progressive motility (OR 3.63; 95% CI 2.49-5.30; P < 0.001), and abnormal forms (OR 3.89; 95% CI 2.71-7.26; P < 0.001). Obesity was associated with reduced progressive motility (OR 1.58; 95% CI 1.14-2.19; P = 0.006) and an increase in abnormal forms (OR 1.87; 95% CI 1.02-3.57; P = 0.021). In contrast, smoking did not contribute significantly to changes in semen parameters. Molecular analysis - Elderly men showed a significantly higher percentage of SDF (23.1 ± 8.7 versus 9.8 ± 2.6%; P < 0.001) and a significantly lower expression of PRM1 (mean fold change 2.2; P = 0.016) and PRM2 (mean fold change 4.6; P < 0.001), compared to younger controls. Furthermore, miR-146a showed a 3-fold lower expression (P < 0.001), miR-371 a 14-fold lower expression (P < 0.001), and miR-122 a 5-fold lower expression (P = 0.01) in the elderly men. LIMITATIONS, REASONS FOR CAUTION: While typical chronic age-related conditions (cardiovascular, respiratory diseases) were excluded, the presence of subclinical underlying diseases cannot be excluded in the elderly population. Subjects referred to our clinic might not be fully representative of the general population. Although a careful medical history and physical examination excluded most andrological conditions that might affect spermatogenesis, we cannot exclude the presence of possible asymptomatic or idiopathic conditions. Furthermore, TUNEL, in common with other SDF detection methods (with the exception of the alkaline comet assay), does not distinguish between single and double strand breaks. WIDER IMPLICATIONS OF THE FINDINGS: The role of obesity suggests that conditions related to lifestyle factors may further worsen age-related sperm parameter impairment. Increased SDF and altered protamine expression suggest the genomic fragility of sperm in advanced age. Changes in the miRNA expression pattern with age could contribute to the identification of a characteristic molecular signature of the ageing process, a potential new biomarker for male reproductive function during the physiological ageing process. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by a grant from the Italian Ministry of Education and Research (MIUR-PRIN 2015- 2015XSNA83-002) and 'Sapienza' University of Rome Faculty of Medicine. The authors have no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Sperm glyceraldehyde 3-phosphate dehydrogenase gene expression in asthenozoospermic spermatozoa.

It has been suggested that the energy required for sperm motility is produced by oxidative phosphorylation while glycolysis seems to be an important source for ATP transmission along the flagellum. Some studies have investigated the chemical and kinetic properties of the enzyme glyceraldehyde 3-phosphate dehydrogenase to identify any changes in the regulation of glycolysis and sperm motility. In contrast, there are few studies analyzing the genetic basis of hypokinesis. For this reason, we investigated the glyceraldehyde 3-phosphate dehydrogenase gene in human sperm to evaluate whether asthenozoospermia was correlated with any changes in its expression. Semen examination and glyceraldehyde 3-phosphate dehydrogenase gene expression studies were carried out on 116 semen samples divided into two groups - Group A consisted of 58 normokinetic samples and Group B of 58 hypokinetic samples. Total RNA was extracted from spermatozoa, and real-time PCR quantification of mRNA was carried out using specific primers and probes. The expression profiles for the Groups A and B were very similar. The mean delta Ct was as follows - Group A, 5.79 ± 1.04; Group B, 5.47 ± 1.27. Our study shows that in human sperm, there is no difference in glyceraldehyde 3-phosphate dehydrogenase gene expression between samples with impaired motility and samples with normal kinetics. We believe that this study could help in the understanding of the molecular mechanisms of sperm kinetics, suggesting that hypomotility may be due to a possible posttranscriptional impairment of the control mechanism, such as mRNA splicing, or to posttranslational changes.

Sperm DNA fragmentation in Italian couples with recurrent pregnancy loss.

The aetiopathogenesis of recurrent pregnancy loss (RPL) is heterogeneous. The aim of this study was to investigate the male factor in Italian couples experiencing RPL following natural conception. The study investigated 112 men from RPL couples and two control groups: 114 infertile men with one or more impaired semen parameters and 114 fertile men with high-quality semen parameters. Semen parameters were examined according to WHO criteria. Sperm DNA fragmentation (SDF) was evaluated using TdT-mediated dUDP nick-end labelling (TUNEL) assay. With the exception of ejaculate volume, the seminal profile of patients with RPL was similar to that of fertile patients and better than the infertile ones. Despite good spermatogenesis, however, sperm DNA integrity was impaired in the RPL group, with SDF values significantly higher than in fertile controls (18.8 ± 7.0 versus 12.8 ± 5.3, P < 0.001) and similar to those of infertile patients. SDF also showed a positive correlation with the age of patients with RPL and number of miscarriages. The results suggest a correlation between increased SDF and impaired reproductive capacity in terms of both fertilization and pregnancies carried to term, but high SDF cannot yet be considered a predictive factor for the risk of RPL.

Differential expression of miRNAs in the seminal plasma and serum of testicular cancer patients.

Various microRNAs from the miR-371-3 and miR-302a-d clusters have recently been proposed as markers for testicular germ cell tumours. Upregulation of these miRNAs has been found in both the tissue and serum of testicular cancer patients, but they have never been studied in human seminal plasma. The aim of this study was, therefore, to assess the differences in the expression of miR-371-3 and miR-302a-d between the seminal plasma and serum of testicular cancer patients, and to identify new potential testicular cancer markers in seminal plasma. We investigated the serum and seminal plasma of 28 pre-orchiectomy patients subsequently diagnosed with testicular cancer, the seminal plasma of another 20 patients 30 days post-orchiectomy and a control group consisting of 28 cancer-free subjects attending our centre for an andrological check-up. Serum microRNA expression was analysed using RT-qPCR. TaqMan Array Card 3.0 platform was used for microRNA profiling in the seminal plasma of cancer patients. Results for both miR-371-3 and the miR-302 cluster in the serum of testicular cancer patients were in line with literature reports, while miR-371and miR-372 expression in seminal plasma showed the opposite trend to serum. On array analysis, 37 miRNAs were differentially expressed in the seminal plasma of cancer patients, and the upregulated miR-142 and the downregulated miR-34b were validated using RT-qPCR. Our study investigated the expression of miRNAs in the seminal plasma of patients with testicular cancer for the first time. Unlike in serum, miR-371-3 cannot be considered as markers in seminal plasma, whereas miR-142 levels in seminal plasma may be a potential marker for testicular cancer.

Identification and characterization of KCASH2 and KCASH3, 2 novel Cullin3 adaptors suppressing histone deacetylase and Hedgehog activity in medulloblastoma.

Medulloblastoma is the most common pediatric malignant brain tumor, arising from aberrant cerebellar precursors' development, a process mainly controlled by Hedgehog (Hh) signaling pathway. Histone deacetylase HDAC1 has been recently shown to modulate Hh signaling, deacetylating its effectors Gli1/2 and enhancing their transcriptional activity. Therefore, HDAC may represent a potential therapeutic target for Hh-dependent tumors, but still little information is available on the physiological mechanisms of HDAC regulation. The putative tumor suppressor REN(KCTD11) acts through ubiquitination-dependent degradation of HDAC1, thereby affecting Hh activity and medulloblastoma growth. We identify and characterize here two REN(KCTD11) homologues, defining a new family of proteins named KCASH, as "KCTD containing, Cullin3 adaptor, suppressor of Hedgehog." Indeed, the novel genes (KCASH2(KCTD21) and KCASH3(KCTD6)) share with REN(KCTD11) a number of features, such as a BTB domain required for the formation of a Cullin3 ubiquitin ligase complex and HDAC1 ubiquitination and degradation capability, suppressing the acetylation-dependent Hh/Gli signaling. Expression of KCASH2 and -3 is observed in cerebellum, whereas epigenetic silencing and allelic deletion are observed in human medulloblastoma. Rescuing KCASHs expression reduces the Hedgehog-dependent medulloblastoma growth, suggesting that loss of members of this novel family of native HDAC inhibitors is crucial in sustaining Hh pathway-mediated tumorigenesis. Accordingly, they might represent a promising class of endogenous "agents" through which this pathway may be targeted.

Histone deacetylase and Cullin3-REN(KCTD11) ubiquitin ligase interplay regulates Hedgehog signalling through Gli acetylation.

Hedgehog signalling is crucial for development and is deregulated in several tumours, including medulloblastoma. Regulation of the transcriptional activity of Gli (glioma-associated oncogene) proteins, effectors of the Hedgehog pathway, is poorly understood. We show here that Gli1 and Gli2 are acetylated proteins and that their HDAC-mediated deacetylation promotes transcriptional activation and sustains a positive autoregulatory loop through Hedgehog-induced upregulation of HDAC1. This mechanism is turned off by HDAC1 degradation through an E3 ubiquitin ligase complex formed by Cullin3 and REN, a Gli antagonist lost in human medulloblastoma. Whereas high HDAC1 and low REN expression in neural progenitors and medulloblastomas correlates with active Hedgehog signalling, loss of HDAC activity suppresses Hedgehog-dependent growth of neural progenitors and tumour cells. Consistent with this, abrogation of Gli1 acetylation enhances cellular proliferation and transformation. These data identify an integrated HDAC- and ubiquitin-mediated circuitry, where acetylation of Gli proteins functions as an unexpected key transcriptional checkpoint of Hedgehog signalling.

Concerted microRNA control of Hedgehog signalling in cerebellar neuronal progenitor and tumour cells.

MicroRNAs (miRNA) are crucial post-transcriptional regulators of gene expression and control cell differentiation and proliferation. However, little is known about their targeting of specific developmental pathways. Hedgehog (Hh) signalling controls cerebellar granule cell progenitor development and a subversion of this pathway leads to neoplastic transformation into medulloblastoma (MB). Using a miRNA high-throughput profile screening, we identify here a downregulated miRNA signature in human MBs with high Hh signalling. Specifically, we identify miR-125b and miR-326 as suppressors of the pathway activator Smoothened together with miR-324-5p, which also targets the downstream transcription factor Gli1. Downregulation of these miRNAs allows high levels of Hh-dependent gene expression leading to tumour cell proliferation. Interestingly, the downregulation of miR-324-5p is genetically determined by MB-associated deletion of chromosome 17p. We also report that whereas miRNA expression is downregulated in cerebellar neuronal progenitors, it increases alongside differentiation, thereby allowing cell maturation and growth inhibition. These findings identify a novel regulatory circuitry of the Hh signalling and suggest that misregulation of specific miRNAs, leading to its aberrant activation, sustain cancer development.

An integrated approach identifies Nhlh1 and Insm1 as Sonic Hedgehog-regulated genes in developing cerebellum and medulloblastoma.

Medulloblastoma (MB) is the most common malignant brain tumor of childhood arising from deregulated cerebellar development. Sonic Hedgehog (Shh) pathway plays a critical role in cerebellar development and its aberrant expression has been identified in MB. Gene expression profiling of cerebella from 1- to 14-day-old mice unveiled a cluster of genes whose expression correlates with the levels of Hedgehog (HH) activity. From this cluster, we identified Insm1 and Nhlh1/NSCL1 as novel HH targets induced by Shh treatment in cultured cerebellar granule cell progenitors. Nhlh1 promoter was found to be bound and activated by Gli1 transcription factor. Remarkably, the expression of these genes is also upregulated in mouse and human HH-dependent MBs, suggesting that they may be either a part of the HH-induced tumorigenic process or a specific trait of HH-dependent tumor cells.