Long Noncoding RNA PANDA Positively Regulates Proliferation of Osteosarcoma Cells.

BACKGROUND: A long noncoding RNA, p21-associated ncRNA DNA damage-activated (PANDA), associates with nuclear transcription factor Y subunit alpha (NF-YA) and inhibits its binding to promoters of apoptosis-related genes, thereby repressing apoptosis in normal human fibroblasts. Here, we show that PANDA is involved in regulating proliferation in the U2OS human osteosarcoma cell line. MATERIALS AND METHODS: U2OS cells were transfected with siRNAs against PANDA 72 h later and they were subjected to reverse transcription-polymerase chain reaction (RT-PCR), quantitative RT-PCR and cell-cycle analysis. RESULTS: PANDA was highly expressed in U2OS cells, and its expression was induced by DNA damage. Silencing PANDA caused arrest at the G1 phase of the cell cycle, leading to inhibition of cell proliferation. Quantitative RT-PCR showed that silencing PANDA increased mRNA levels of the cyclin-dependent kinase inhibitor p18, which caused G1 phase arrest. CONCLUSION: These results suggest that PANDA promotes G1-S transition by repressing p18 transcription, and thus promotes U2OS cell proliferation.

Y-box Binding Protein 1 Is Involved in Regulating the G2/M Phase of the Cell Cycle.

BACKGROUND/AIM: The transcription factor Y-box-binding protein 1 (YB1) is overexpressed in many types of human cancers. YB1 regulates the G1 phase of the cell cycle by controlling transcription of G1 regulators. Here, we report that YB1 is also involved in regulating G2/M phase. MATERIALS AND METHODS: YB1-depleted TKO cells were subjected to quantitative reverse transcription-polymerase chain reaction and cell-cycle analysis. RNA immunoprecipitation (RIP)-chip assay was performed using anti-YB1 antibodies. Precipitated RNAs were subjected to microarray analysis. RESULTS: Silencing YB1 inhibited the proliferation of TKO cells, which lost the machinery required for G1 phase arrest. Cell-cycle analysis showed that silencing YB1 caused G2/M phase cell-cycle arrest. RIP-chip assay showed that YB1 associated with mRNA of multiple cell-cycle-related genes, including G2/M phase regulators. CONCLUSION: YB1 positively regulates not only the G1 phase but also G2/M phase by regulating multiple cell-cycle-related genes.

Influence of the Different Primary Cancers and Different Types of Bone Metastasis on the Lesion-based Artificial Neural Network Value Calculated by a Computer-aided Diagnostic System, BONENAVI, on Bone Scintigraphy Images.

OBJECTIVES: BONENAVI, a computer-aided diagnostic system, is used in bone scintigraphy. This system provides the artificial neural network (ANN) and bone scan index (BSI) values. ANN is associated with the possibility of bone metastasis, while BSI is related to the amount of bone metastasis. The degree of uptake on bone scintigraphy can be affected by the type of bone metastasis. Therefore, the ANN value provided by BONENAVI may be influenced by the characteristics of bone metastasis. In this study, we aimed to assess the relationship between ANN value and characteristics of bone metastasis. METHODS: We analyzed 50 patients (36 males,14 females; age range: 87-42 yrs median age:72.5 yrs) with prostate, breast, or lung cancer who had undergone bone scintigraphy and were diagnosed with bone metastasis (32 cases of prostate cancer, nine cases of breast cancer, and nine cases of lung cancer). Those who had received systematic therapy over the past years were excluded. Bone metastases were diagnosed clinically, and the type of bone metastasis (osteoblastic, mildly osteoblastic, osteolytic, and mixed components) was decided visually by the agreement of two radiologists. We compared the ANN values (case-based and lesion-based) among the three primary cancers and four types of bone metastasis. RESULTS: There was no significant difference in case-based ANN values among prostate, breast, and lung cancers. However, the lesion-based ANN values were the highest in cases with prostate cancer and the lowest in cases of lung cancer (median values: prostate cancer, 0.980; breast cancer 0.909; and lung cancer, 0.864). Mildly osteoblastic lesions showed significantly lower ANN values than the other three types of bone metastasis (median values: osteoblastic,; 0.939 mildly osteoblastic; 0.788, mixed type; 0.991, and osteolytic. 0.969) The possibility of a lesion-based ANN value below 0.5 was %10.9 for bone metastasis in prostate cancer, %12.9 for breast cancer, and %37.2 for lung cancer. The corresponding possibility were %14.7 for osteoblastic metastases, %23.9 for mildly osteoblastic metastases, %7.14 for mixed-type metastases, and %16.0 for osteolytic metastases. CONCLUSION: The lesion-based ANN values calculated by BONENAVI can be influenced by the type of primary cancer and bone metastasis.

Impact of patient age on the iodine/FDG "flip-flop" phenomenon in lung metastasis from thyroid cancer.

OBJECTIVES: Radioiodine therapy is an effective treatment for lung metastasis from thyroid cancer. However, cases of lung metastasis without iodine uptake are often encountered. In such cases, FDG accumulation in lung lesions is often observed. There is a reverse relationship between iodine and FDG accumulation in thyroid cancer lesions, the so-called "flip-flop" phenomenon. The aim of this study was to assess the relationship between patient age and the occurrence of the flip-flop phenomenon. METHODS: Eighty-six patients who underwent radioiodine therapy for lung metastasis were studied retrospectively (age 17-73 years; median 60 years; males:females 22:64). We compared the clinical data and imaging findings (size and FDG uptake of lung nodules) between patients with (n = 44) and without (n = 42) iodine uptake in lung metastasis. RESULTS: Significantly more young patients showed iodine accumulation in lung metastasis than old patients (p = 0.0025). Lung metastases with larger size or greater FDG uptake showed no iodine uptake more frequently with significant difference (p = 0.015 and <0.001, respectively). Among patients with FDG uptake in the lung metastasis, 57.1 % of young patients (<60 years) and 24.3 % of the old patients (≥60 years) showed iodine uptake (p = 0.0029). CONCLUSIONS: Higher patient age and lung nodules with large size or FDG accumulation are negative factors for iodine accumulation in lung metastases from thyroid cancer. In addition, our results show that young patients have a greater likelihood of iodine uptake even when FDG accumulates in lung metastasis, in contrast to old patients.

Crystal-storing histiocytosis associated with marginal-zone lymphoma.

We report a rare case of crystal-storing histiocytosis (CSH) associated with marginal-zone lymphoma. A 91-year-old woman with a history of breast cancer presented with masses of the posterior neck, right breast, and left upper arm. An enlarging mass of the neck was removed and was histologically diagnosed as CSH, associated with marginal-zone lymphoma. Masses in the breast and upper arm were evaluated by needle biopsy and revealed as CSH. CSH is a rare condition characterized by the intrahistiocytic accumulation of crystallized immunoglobulins, and is associated with disorders in which monoclonal immunoglobulins are expressed. To the best of our knowledge, there are few previous descriptions of CSH which include the imaging features of this disease. In the present case, the masses showed hypoechogenicity with internal patchy hyperechoic areas on ultrasonography, and an iso-signal to slight hyperintensity compared with muscle on T2-weighted magnetic resonance imaging. We report the imaging findings in CSH and discuss their diagnostic implications.