SARM1 deletion delays cerebellar but not spinal cord degeneration in an enhanced mouse model of SPG7 deficiency.

Hereditary spastic paraplegia is a neurological condition characterized by predominant axonal degeneration in long spinal tracts, leading to weakness and spasticity in the lower limbs. The nicotinamide adenine dinucleotide (NAD+)-consuming enzyme SARM1 has emerged as a key executioner of axonal degeneration upon nerve transection and in some neuropathies. An increase in the nicotinamide mononucleotide/NAD+ ratio activates SARM1, causing catastrophic NAD+ depletion and axonal degeneration. However, the role of SARM1 in the pathogenesis of hereditary spastic paraplegia has not been investigated. Here, we report an enhanced mouse model for hereditary spastic paraplegia caused by mutations in SPG7. The eSpg7 knockout mouse carries a deletion in both Spg7 and Afg3l1, a redundant homologue expressed in mice but not in humans. The eSpg7 knockout mice recapitulate the phenotypic features of human patients, showing progressive symptoms of spastic-ataxia and degeneration of axons in the spinal cord as well as the cerebellum. We show that the lack of SPG7 rewires the mitochondrial proteome in both tissues, leading to an early onset decrease in mito-ribosomal subunits and a remodelling of mitochondrial solute carriers and transporters. To interrogate mechanisms leading to axonal degeneration in this mouse model, we explored the involvement of SARM1. Deletion of SARM1 delays the appearance of ataxic signs, rescues mitochondrial swelling and axonal degeneration of cerebellar granule cells and dampens neuroinflammation in the cerebellum. The loss of SARM1 also prevents endoplasmic reticulum abnormalities in long spinal cord axons, but does not halt the degeneration of these axons. Our data thus reveal a neuron-specific interplay between SARM1 and mitochondrial dysfunction caused by lack of SPG7 in hereditary spastic paraplegia.

Local Disease-Free Survival Rate (LSR) Application to Personalize Radiation Therapy Treatments in Breast Cancer Models.

Cancer heterogeneity represents the main issue for defining an effective treatment in clinical practice, and the scientific community is progressively moving towards the development of more personalized therapeutic regimens. Radiotherapy (RT) remains a fundamental therapeutic treatment used for many neoplastic diseases, including breast cancer (BC), where high variability at the clinical and molecular level is known. The aim of this work is to apply the generalized linear quadratic (LQ) model to customize the radiant treatment plan for BC, by extracting some characteristic parameters of intrinsic radiosensitivity that are not generic, but may be exclusive for each cell type. We tested the validity of the generalized LQ model and analyzed the local disease-free survival rate (LSR) for breast RT treatment by using four BC cell cultures (both primary and immortalized), irradiated with clinical X-ray beams. BC cells were chosen on the basis of their receptor profiles, in order to simulate a differential response to RT between triple negative breast and luminal adenocarcinomas. The MCF10A breast epithelial cell line was utilized as a healthy control. We show that an RT plan setup based only on α and ß values could be limiting and misleading. Indeed, two other parameters, the doubling time and the clonogens number, are important to finely predict the tumor response to treatment. Our findings could be tested at a preclinical level to confirm their application as a variant of the classical LQ model, to create a more personalized approach for RT planning.

Radiosensitizing effect of curcumin-loaded lipid nanoparticles in breast cancer cells.

In breast cancer (BC) care, radiotherapy is considered an efficient treatment, prescribed both for controlling localized tumors or as a therapeutic option in case of inoperable, incompletely resected or recurrent tumors. However, approximately 90% of BC-related deaths are due to the metastatic tumor progression. Then, it is strongly desirable to improve tumor radiosensitivity using molecules with synergistic action. The main aim of this study is to develop curcumin-loaded solid nanoparticles (Cur-SLN) in order to increase curcumin bioavailability and to evaluate their radiosensitizing ability in comparison to free curcumin (free-Cur), by using an in vitro approach on BC cell lines. In addition, transcriptomic and metabolomic profiles, induced by Cur-SLN treatments, highlighted networks involved in this radiosensitization ability. The non tumorigenic MCF10A and the tumorigenic MCF7 and MDA-MB-231 BC cell lines were used. Curcumin-loaded solid nanoparticles were prepared using ethanolic precipitation and the loading capacity was evaluated by UV spectrophotometer analysis. Cell survival after treatments was evaluated by clonogenic assay. Dose-response curves were generated testing three concentrations of free-Cur and Cur-SLN in combination with increasing doses of IR (2-9 Gy). IC50 value and Dose Modifying Factor (DMF) was measured to quantify the sensitivity to curcumin and to combined treatments. A multi-"omic" approach was used to explain the Cur-SLN radiosensitizer effect by microarray and metobolomic analysis. We have shown the efficacy of the Cur-SLN formulation as radiosensitizer on three BC cell lines. The DMFs values, calculated at the isoeffect of SF = 50%, showed that the Luminal A MCF7 resulted sensitive to the combined treatments using increasing concentration of vehicled curcumin Cur-SLN (DMF: 1,78 with 10 µM Cur-SLN.) Instead, triple negative MDA-MB-231 cells were more sensitive to free-Cur, although these cells also receive a radiosensitization effect by combination with Cur-SLN (DMF: 1.38 with 10 µM Cur-SLN). The Cur-SLN radiosensitizing function, evaluated by transcriptomic and metabolomic approach, revealed anti-oxidant and anti-tumor effects. Curcumin loaded- SLN can be suggested in future preclinical and clinical studies to test its concomitant use during radiotherapy treatments with the double implications of being a radiosensitizing molecule against cancer cells, with a protective role against IR side effects.

Trends in combined radio-chemotherapy for locally advanced rectal cancer: a survey among radiation oncology centers of Sicily region on behalf of AIRO.

AIM: To conduct a survey among Sicilian centers of radiation oncology belonging to Associazione Italiana di Radioterapia ed Oncologia Clinica (AIRO), to record the different methods of integration of radio-chemotherapy both in neoadjuvant and adjuvant settings, to evaluate surgical procedures in relation to the sphincter preservation and to report the different toxicity profiles of the treatment strategies. METHODS: A questionnaire was sent at the end of 2017 to all the radiation oncology centers of Sicily region in order to collect the data from individual centers and the treatment characteristics retrospectively over the previous 5 years, from 2012 to 2016. The required data were collected from 13 centers out of 17 which, in relation to the single catchment areas, correspond to approximately 85% of the Sicilian population. The requested data concerned the type of integrated treatment (neoadjuvant vs adjuvant vs radical), combination with chemotherapy (induction, concomitant, adjuvant), type of surgical intervention (sphincter-saving vs abdomino-perineal resection), disease stage, schedule and radiotherapy technique adopted, as well as toxicity detected over the treatment period. RESULTS: A total of 784 pts (M/F: 509/275) were treated between 2012 and 2016, with a median age of 67 years (range 25-92). The majority of patients was treated in the neoadjuvant phase (62% of the total) compared to the adjuvant phase (31%) and to those treated radically (7%). Twenty-five percent of patients did not receive combination chemotherapy mainly for cardiovascular problems. Chemotherapy used concomitantly to radiotherapy was single-agent capecitabine (73% of patients) or 5-fluorouracil (27%). The use of chemotherapy alone before concomitant treatment is more common for patients treated in the adjuvant phase (64% of this subgroup), while 14% of patients treated in the neoadjuvant phase received induction chemotherapy before the concomitant phase; in both cases of chemotherapy alone, the majority of patients (91%) received oxaliplatin-based protocols (FOLFOX/XELOX/CAPOX). Few patients (3%) received chemotherapy alone after the concomitant phase. Information on the surgical treatment received is available for 88% of the sample. Of these, 93% received a surgical treatment. The overall rate of sphincter-saving surgery (anterior resection) was 72%, but the contribution of neoadjuvant treatment allowed to reach a rate of 83% in this subgroup (against 65% found in the subgroup of patients treated in adjuvant phase). Traditional radiotherapy schedule (45-50 Gy in 25-28 fractions) was used in 90% of patients, of which an intensified treatment in neoadjuvant phase (45 Gy + boost of 9-10 Gy) was used in 11% of patients. A short-course regimen (25 Gy in 5 fraction) in neoadjuvant setting was opted rarely (7%). Three-dimensional conformal technique was preferred over intensity-modulated ones (73% vs 27%). Toxicity was mainly of grade I-II CTCAE (skin 23%, gastrointestinal 39%, genitourinary 14%) compared to grade III (gastrointestinal 4%, genitourinary and hematological < 1%). Interestingly, the toxicity rates were significantly higher in the adjuvant group compared to the neoadjuvant (GI: 58% vs 31%, GU: 21% vs 10%). CONCLUSION: The present survey shows that in the Sicily region integrated therapies for rectal cancer have allowed a neoadjuvant approach in the majority of patients, thus resulting in a greater use of sphincter conservative surgery. The toxicity has also been reported to be significantly less in this treatment setting.

Transitional cell carcinoma of endometrium: a case report of rare pure form.

Transitional cell carcinoma is a very rare histological subtype of endometrial cancer, with only 18 cases described in literature. Ovary represents the most common site where it accounts for 2% of all ovarian cancers. Due to the rarity of this disease, current management is controversial and includes various approaches, mostly described in the adjuvant setting, both radiotherapy and chemotherapy alone or in combination. Here, we report a case of a 65-year-old patient who underwent adjuvant vaginal brachytherapy for an endometrial transitional cell carcinoma. The patient was treated with radical total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH-BSO), without lymph-node sampling, and adjuvant endocavitary brachytherapy delivering 30 Gy in 5 fractions in consecutive days. Treatment tolerance was excellent, with only G1 genitourinary acute toxicity and no other adverse events reported. In this experience, the choice of brachytherapy alone resulted in excellent local control outcomes. However, the patient developed a distant recurrence after 43 months and chemotherapy was applied. More research is required to determine the most effective treatment for this rare histological subtype, and in particular, the role of chemotherapy and radiotherapy combinations.

Optimal local control and tolerability of three-dimensional conformal radiation therapy in prostate cancer: a single institutional experience of dose escalation in 125 patients.

AIMS: To evaluate long-term late side effects, clinical and biochemical relapse in non-metastatic prostate cancer patients treated with dose escalation, from 74 to 78 Gy, by means of three dimensional conformal radiation therapy. MATERIALS AND METHODS: Clinical data of 125 patients with prostate cancer who underwent three-dimensional conformal radiation therapy were retrospectively evaluated. All patients were stratified, according to the NCCN classification, in low, intermediate and high risk, and all of them showed histologically proven adenocarcinoma stage T1-T3 with at least 2 years of follow-up. Late toxicity was analyzed using a modified Radiation Therapy Oncology Group toxicity scale. RESULTS: With a median of follow-up of 48 months, grade ≥2 late genitourinary toxicity was reported in 18% and grade ≥2 gastrointestinal toxicity was detected in 12%. The PSA relapse rate was 20% in the high-risk group, 7% in the intermediate-risk group, and 3% in the low-risk group. CONCLUSIONS: Late side effects and tumor control in patients with non-metastatic prostate cancer in dose escalation from 74 to 78 Gy was acceptable. Three-dimensional conformal radiation therapy still represents a valid therapeutic option for departments where intensity-modulated radiation therapy or image-guided radiation therapy is still not available.

Properties of the endogenous components of the thioredoxin system in the psychrophilic eubacterium Pseudoalteromonas haloplanktis TAC 125.

The endogenous components of the thioredoxin system in the Antarctic eubacterium Pseudoalteromonas haloplanktis have been purified and characterised. The temperature dependence of the activities sustained by thioredoxin (PhTrx) and thioredoxin reductase (PhTrxR) pointed to their adaptation in the cold growth environment. PhTrxR was purified as a flavoenzyme and its activity was significantly enhanced in the presence of molar concentration of monovalent cations. The energetics of the partial reactions leading to the whole electron transfer from NADPH to the target protein substrate in the reconstituted thioredoxin system was also investigated. While the initial electron transfer from NADPH to PhTrxR was energetically favoured, the final passage to the heterologous protein substrate enhanced the energetic barrier of the whole process. The energy of activation of the heat inactivation process essentially reflected the psychrophilic origin of PhTrxR. Vice versa, PhTrx possessed an exceptional heat resistance (half-life, 4.4 h at 95 °C), ranking this protein among the most thermostable enzymes reported so far in psychrophiles. PhTrxR was covalently modified by glutathione, mainly by its oxidised or nitrosylated forms. A mutagenic analysis realised on three non catalytic cysteines of the flavoenzyme allowed the identification of C(303) as the target for the S-glutathionylation reaction.

Differential cold-adaptation among protein components of the thioredoxin system in the psychrophilic eubacterium Pseudoalteromonas haloplanktis TAC 125.

Thioredoxin and thioredoxin reductase from the psychrophilic eubacterium Pseudoalteromonas haloplanktis were obtained as recombinant His-tagged proteins (rPhTrx and rPhTrxR, respectively). rPhTrxR is organised as a homodimeric flavoenzyme, whereas rPhTrx is a small monomeric protein, both containing a functional disulfide bridge. However, three additional cysteines are present as free thiols in purified rPhTrxR. When individually tested in specific assays, rPhTrxR and rPhTrx display a full activity at low temperatures, an indispensable requirement for cold-adapted proteins. In particular, rPhTrxR catalyses the NADPH dependent reduction of DTNB and rPhTrx provokes the insulin precipitation in the presence of DTT. The analysis of the effect of temperature on these reactions indicates that rPhTrxR is more cold-adapted than rPhTrx, having a higher psychrophilicity. The combined activity of rPhTrxR and rPhTrx, tested in a reconstituted assay containing NADPH as electrons donor and human insulin as the thioredoxin substrate, demonstrates a direct functional interaction between the purified recombinant components of the thioredoxin system of P. haloplanktis. Furthermore, the NADPH-dependent reduction of rPhTrx catalysed by rPhTrxR is fully reversible and allows the determination of its redox potential, whose value is in the range of other bacterial and archaeal thioredoxins. The analysis of the thermostability of rPhTrxR points to its discrete heat resistance. However, rPhTrx is much more heat resistant, with a half inactivation time of about 4 h at 95 degrees C. This exceptional heat resistance for a psychrophilic protein is significantly decreased by the reduction of the disulfide bridge of rPhTrx. Functionality, thermodependence and thermostability of the P. haloplanktis thioredoxin system point to the relevance of this key mechanism for the preservation of the reduced state of cytoplasmic proteins even in a cold-adapted source.