Recurrence prediction in clear cell renal cell carcinoma using machine learning of quantitative nuclear features.

The recurrence of non-metastatic renal cell carcinoma (RCC) may occur early or late after surgery. This study aimed to develop a recurrence prediction machine learning model based on quantitative nuclear morphologic features of clear cell RCC (ccRCC). We investigated 131 ccRCC patients who underwent nephrectomy (T1-3N0M0). Forty had recurrence within 5 years and 22 between 5 and 10 years; thirty-seven were recurrence-free during 5-10 years and 32 were for more than 10 years. We extracted nuclear features from regions of interest (ROIs) using a digital pathology technique and used them to train 5- and 10-year Support Vector Machine models for recurrence prediction. The models predicted recurrence at 5/10 years after surgery with accuracies of 86.4%/74.1% for each ROI and 100%/100% for each case, respectively. By combining the two models, the accuracy of the recurrence prediction within 5 years was 100%. However, recurrence between 5 and 10 years was correctly predicted for only 5 of the 12 test cases. The machine learning models showed good accuracy for recurrence prediction within 5 years after surgery and may be useful for the design of follow-up protocols and patient selection for adjuvant therapy.

Prediction of non-muscle invasive bladder cancer recurrence using machine learning of quantitative nuclear features.

Non-muscle invasive bladder cancer (NMIBC) generally has a good prognosis; however, recurrence after transurethral resection (TUR), the standard primary treatment, is a major problem. Clinical management after TUR has been based on risk classification using clinicopathological factors, but these classifications are not complete. In this study, we attempted to predict early recurrence of NMIBC based on machine learning of quantitative morphological features. In general, structural, cellular, and nuclear atypia are evaluated to determine cancer atypia. However, since it is difficult to accurately quantify structural atypia from TUR specimens, in this study, we used only nuclear atypia and analyzed it using feature extraction followed by classification using Support Vector Machine and Random Forest machine learning algorithms. For the analysis, 125 patients diagnosed with NMIBC were used; data from 95 patients were randomly selected for the training set, and data from 30 patients were randomly selected for the test set. The results showed that the support vector machine-based model predicted recurrence within 2 years after TUR with a probability of 90% and the random forest-based model with probability of 86.7%. In the future, the system can be used to objectively predict NMIBC recurrence after TUR.

Giant retroperitoneal schwannoma in a 52-year-old man.

Schwannoma in the retroperitoneal space is rare, and it is extremely rare in patients with no history of neurofibromatosis. We present a case of giant retroperitoneal schwannoma in a 52-year-old man who did not have neurofibromatosis. Because malignant transformation would be extremely rare in this circumstance, close imaging follow-up could avert the necessity for complete resection. The possibility of schwannoma should be considered when evaluating retroperitoneal tumors with the characteristic findings, even if there is no connection between the tumor and the intervertebral foramina.

Molecular targeted therapies of renal cell carcinoma considering life stage of the patient: Two case reports.

Molecular targeted therapies have markedly improved the prognosis of metastatic renal cell carcinoma (RCC) and patients are able to receive specific treatments depending on their condition. The cases of two patients who presented with large RCC with very different statuses were examined in the current study. One of the patients was elderly with numerous comorbidities, and the other was young and had Case 1 was an elderly female with various comorbidities including a history of cerebral infarction and impaired eyesight. A 7 cm solid mass in the left kidney, pulmonary metastases and a shrunken right kidney were identified. Conservative treatment was selected and the patient underwent treatment with oral sorafenib for 5 years without experiencing disease progression. Case 2 was a middle-aged male in a good general condition who had a 19 cm left renal mass and multiple metastases. Due to the tumor size, the patient was initially treated with oral pazopanib to reduce the renal tumor volume and was able to undergo left radical nephrectomy after 6 months. Molecular targeted therapies were thus used to treat these patients taking into account each patient's life stage; case 1 was treated without surgery for six years and case 2 received treatment as a neoadjuvant.

Incidental Presacral Myelolipoma Resembling the Liposarcoma: A Case Report and Literature Review.

Presacral myelolipomas are rare, benign, asymptomatic tumors composed of mature adipose tissue and hematopoietic elements, but fewer than 50 cases have been reported in the literature. They are usually discovered incidentally during imaging studies and are often misdiagnosed as liposarcoma, which have a malignant nature, because the imaging findings of myelolipoma can be similar to those of liposarcoma. It is challenging to distinguish presacral myelolipomas from other presacral fat-containing tumors without performing a histological examination. We should consider the possibility of a malignant tumor, and imaging-guided biopsy carries a risk of tumor spread along the biopsy tract. Therefore, surgical management might sometimes be required; however, it is not necessary in all cases. We present an incidentally detected case of presacral myelolipoma that was difficult to differentiate from other malignant tumors in a 71-year-old male.

Annular rectal constriction caused by infiltrating bladder cancer: A case report.

A 69-year-old man was referred to our hospital with chief complaints of urinary incontinence, pollakiuria, thin stools and edema of the left lower extremity. Computed tomography and magnetic resonance imaging revealed bilateral hydronephrosis, thickening of the rectal and posterolateral bladder walls, and enlargement of the left obturator lymph nodes, suggesting metastasis. The carcinoembryonic antigen and carbohydrate antigen 19-9 levels were 5.6 ng/ml and 460.1 U/ml, respectively. A transurethral bladder biopsy revealed grade 2 urothelial carcinoma with glandular differentiation. A transrectal needle biopsy suggested cancer infiltration of the rectal wall and an annular rectal constriction caused by an infiltrating bladder cancer was diagnosed. Three courses of gemcitabine and cisplatin chemotherapy were administered and demonstrated good efficacy.

Individual and combining effects of anti-RANKL monoclonal antibody and teriparatide in ovariectomized mice.

We examined the individual and combined effects of teriparatide and anti-RANKL (receptor activator of nuclear factor κB ligand) monoclonal antibody in ovariectomized mice. Three-month-old female C57BL/6 mice were ovariectomized (OVX) or sham operated. Four weeks after OVX, they were assigned to 3 different groups to receive anti-RANKL monoclonal antibody (Ab) alone (5 mg/kg single injection at 4 weeks after OVX, Ab group), teriparatide alone (80 µg/kg daily injection for 4 weeks from 4 weeks after OVX, PTH group), or mAb plus teriparatide (Ab + PTH group). Mice were sacrificed 8 weeks after OVX. Bone mineral density (BMD) was measured at the femur and lumbar spine. Hind limbs were subjected to histological and histomorphometric analysis. Serum osteocalcin and CTX-I levels were measured to investigate the bone turnover. Compared with Ab group, Ab + PTH group showed a significant increase in BMD at distal femur and femoral shaft. Cortical bone volume was significantly increased in PTH and Ab + PTH groups compared with Ab group. Bone turnover in Ab + PTH group was suppressed to the same degree as in Ab group. The number of TRAP-positive multinucleated cells was markedly reduced in Ab and Ab + PTH groups. These results suggest that combined treatment of teriparatide with anti-RANKL antibody has additive effects on BMD in OVX mice compared with individual treatment.

Genomewide comprehensive analysis reveals critical cooperation between Smad and c-Fos in RANKL-induced osteoclastogenesis.

We have previously reported that transforming growth factor ß (TGF-ß) plays an essential role in receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis. However, the detailed underlying molecular mechanisms still remain unclear. Formaldehyde-assisted isolation of regulatory elements (FAIRE) and chromatin immunoprecipitation (ChIP) followed by sequencing (FAIRE-seq and ChIP-seq) analyses indicated the cooperation of Smad2/3 with c-Fos during osteoclastogenesis. Biochemical analysis and immunocytochemical analysis revealed that physical interaction between Smad2/3 and c-Fos is required for their nuclear translocation. The gene expression of nuclear factor of activated T-cells, cytoplasmic 1 (Nfatc1), a key regulator of osteoclastogenesis, was regulated by RANKL and TGF-ß, and c-Fos binding to open chromatin sites was suppressed by inhibition of TGF-ß signaling by SB431542. Conversely, Smad2/3 binding to Nfatc1 was impaired by c-Fos deficiency. These results suggest that TGF-ß regulates RANKL-induced osteoclastogenesis through reciprocal cooperation between Smad2/3 and c-Fos.

Anti-apoptotic Bcl-2 family member Mcl-1 regulates cell viability and bone-resorbing activity of osteoclasts.

Myeloid cell leukemia sequence 1 (Mcl-1) is an anti-apoptotic Bcl-2 family protein and an immediate early gene expressed during myeloid leukemia cell line differentiation. We analyzed the expression and function of Mcl-1 in osteoclasts. Mcl-1 protein exhibited a short half-life in osteoclasts caused by its degradation in the ubiquitin-proteasome system. Mcl-1 had no effect on osteoclast differentiation, but its overexpression prolonged osteoclast survival and suppressed the bone-resorbing activity of these cells, as determined by pit formation assay. Conversely, Mcl-1 depletion suppressed osteoclast survival and increased bone resorption. This negative role for Mcl-1 on the bone-resorptive activities of osteoclasts may be caused by the increase in adenosine triphosphate/adenosine diphosphate ratio. Finally, we showed that the local deletion of Mcl-1 by the injection of the Cre adenovirus into the calvaria of Mcl1(fl/fl) mice significantly affected GST-RANKL-induced bone resorption in vivo. These results demonstrated that Mcl-1 positively regulates cell viability and negatively regulates the bone-resorbing activity of osteoclasts both in vitro and in vivo.

[Updates of denosumab, anti-RANKL antibody for osteoporosis].

Osteoporosis and osteoporosis-related fractures tend to increase year by year around the world including Japan. Denosumab, a fully human monoclonal antibody to receptor activator of NF-κB ligand (RANKL) , a cytokine member of the TNF family essential for osteoclast differentiation has recently been approved in Japan, Europe and the US for the treatment of postomenopausal osteoporosis as well as bone metastasis. In some large clinical trials, denosumab significantly decreased bone resorption, increased bone mineral density (BMD) , and reduced the risk of vertebral, nonvertebral and hip fractures in postmenopausal women. However, the mechanism of adverse events of denosumab, such as hypocalcemia and osteonecrosis of the jaws, has not been completely explained. Therefore, further knowledge should be accumulated by additional basic researches and clinical studies on denosumab.

Bone resorption is regulated by cell-autonomous negative feedback loop of Stat5-Dusp axis in the osteoclast.

Signal transducer and activator of transcription 5 (Stat5) is essential for cytokine-regulated processes such as proliferation, differentiation, and survival in hematopoietic cells. To investigate the role of Stat5 in osteoclasts, we generated mice with an osteoclast-specific conditional deletion of Stat5 (Stat5 conditional knockout [cKO] mice) and analyzed their bone phenotype. Stat5 cKO mice exhibited osteoporosis caused by an increased bone-resorbing activity of osteoclasts. The activity of mitogen-activated protein kinases (MAPKs), in particular extracellular signal-related kinase, was increased in Stat5 cKO osteoclasts, whereas the expression of the MAPK phosphatases dual specificity phosphatase 1 (Dusp1) and Dusp2 was significantly decreased. Interleukin-3 (IL-3) stimulated the phosphorylation and nuclear translocation of Stat5 in osteoclasts, and Stat5 expression was up-regulated in response to receptor activator of nuclear factor κB ligand (RANKL). The results suggest that Stat5 negatively regulates the bone-resorbing function of osteoclasts by promoting Dusp1 and Dusp2 expression, and IL-3 promotes Stat5 activation in osteoclasts.

Regulation of bone resorption and sealing zone formation in osteoclasts occurs through protein kinase B-mediated microtubule stabilization.

We investigated the role of protein kinase B (Akt), a downstream effector of phosphatidylinositol 3-kinase, in bone-resorbing activity of mature osteoclasts. Treatment with a specific Akt inhibitor disrupted sealing zone formation and decreased the bone-resorbing activity of osteoclasts. The normal microtubule structures were lost and the Akt inhibitor reduced the amount of acetylated tubulin, which reflects stabilized microtubules, whereas forced Akt activation by adenovirus vectors resulted in the opposite effect. Forced Akt activation increased the binding of the microtubule-associated protein adenomatous polyposis coli (APC), the APC-binding protein end-binding protein 1 (EB1) and dynactin, a dynein activator complex, with microtubules. Depletion of Akt1 and Akt2 resulted in a disconnection of APC/EB1 and a decrease in bone-resorbing activity along with reduced sealing zone formation, both of which were recovered upon the addition of LiCl, a glycogen synthase kinase-3ß (GSK-3ß) inhibitor. The Akt1 and Akt2 double-knockout mice exhibited osteosclerosis due to reduced bone resorption. These findings indicate that Akt controls the bone-resorbing activity of osteoclasts by stabilizing microtubules via a regulation of the binding of microtubule associated proteins.

[Cytokines in bone diseases. Genetic disorders of RANKL-RANK-OPG system].

It is now widely recognized that the RANKL-RANK-OPG signaling system plays an important role in the differentiation, activation and cell death of osteoclasts. Recently, several genetic disorders involving the RANKL-RANK-OPG system have been discovered. In this article, we would like to show a brief review on a genetic disorder familial expansile osteolysis (FEO) , in which RANK gene mutation was identified, and other genetic disorders of the RANKL-RANK-OPG system.