ASCT2 defined by enzyme-mediated activation of radical sources enhances malignancy of GD2-plus small cell lung cancer

Abstract

Ganglioside GD2 is specifically expressed in small cell lung cancer (SCLC) cells, leading to enhancement of malignant phenotypes, such as cell proliferation and migration. However, how GD2 promotes malignant phenotypes in SCLC cells is not well known. In this study, to reveal mechanisms by which GD2 increases malignant phenotypes in SCLC cells, we performed enzyme-mediated activation of radical sources combined with mass spectrometry in GD2 positive (+) SCLC cells. Consequently, we identified ASC amino-acid transporter 2 (ASCT2), a major glutamine transporter, which coordinately works with GD2. We showed that ASCT2 was highly expressed in glycolipid-enriched microdomain/rafts in GD2(+) SCLC cells, and co-localized with GD2 in proximity ligation assay and immunocytostaining, and bound with GD2 in immuneoprecipitation/TLC-immunostaining. Malignant phenotypes of GD2(+) SCLC cells were enhanced via glutamine uptake, and were suppressed by L-γ-glutamyl-p-nitroanilide, a specific inhibitor of ASCT2, via reduced phosphorylation of p70 S6K1 and S6. These results suggested that ASCT2 enhances glutamine uptake in GEM/rafts in GD2(+) SCLC cells, leading to the enhancement of cell proliferation and migration through increased phosphorylation of mTORC1 signaling axis.

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Detection of CTCs in cervical cancer using a conditionally replicative adenovirus targeting telomerase-positive cells

Abstract

Circulating tumor cells (CTCs) are newly discovered biomarkers of cancers. Although many systems detect CTCs, a gold standard has not yet been established. We analyzed CTCs in uterine cervical cancer patients using an advanced version of conditionally replicative adenovirus targeting telomerase-positive cells, which was enabled to infect coxsackievirus-adenovirus receptor-negative cells and to reduce false-positive signals in myeloid cells. Blood samples from cervical cancer patients were hemolyzed and infected with the virus and then labeled with fluorescent anti-CD45 and anti-pan cytokeratin antibodies. GFP (+)/CD45 (−) cells were isolated and subjected to whole-genome amplification followed by polymerase chain reaction analysis of human papillomavirus (HPV) DNA. CTCs were detected in 6 of 23 patients with cervical cancers (26.0%). The expression of CTCs did not correlate with the stage of cancer or other clinicopathological factors. In 5 of the 6 CTC-positive cases, the same subtype of HPV DNA as that of the corresponding primary lesion was detected, indicating that the CTCs originated from HPV-infected cancer cells. These CTCs were all negative for cytokeratins. The CTCs detected by our system were genetically confirmed. CTCs derived from uterine cervical cancers had lost epithelial characteristics, indicating that epithelial marker-dependent systems do not have the capacity to detect these cells in cervical cancer patients.

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Clinical significance of disease-specific MYD88 mutations in circulating DNA in primary central nervous system lymphoma

Abstract

Recent sequencing studies demonstrated the MYD88 L265P mutation in more than 70% of primary central nervous system lymphomas (PCNSL), and the clinical significance of this mutation has been proposed as diagnostic and prognostic markers in PCNSL. On the other hand, mutational analyses using cell-free DNAs have been reported in a variety of systemic lymphomas. To investigate how sensitively the MYD88 L265P mutation can be identified in cell-free DNA from PCNSL patients, we performed droplet digital PCR (ddPCR) and targeted deep sequencing (TDS) in consecutive 14 PCNSL patients from whom paired tumor-derived DNA and cell-free DNA was available at diagnosis. The MYD88 L265P mutation was found in tumor-derived DNA from all 14 patients (14/14, 100%). In contrast, among 14 cell-free DNAs evaluated by ddPCR (14/14) and TDS (13/14), MYD88 L265P mutation was detected in eight out of 14 (ddPCR) and 0 out of 13 (TDS) samples, implying dependence on the detection method. After chemotherapy, the MYD88 L265P mutation in cell-free DNAs was traced in five patients; unexpectedly, the mutations disappeared after the chemotherapy was given, and they remained undetectable in all patients. These observations suggest that ddPCR can sensitively detect the MYD88 L265P mutation in cell-free DNA and could be used as non-invasive diagnostics, but may not be applicable for monitoring minimal residual diseases in PCNSL.

This article is protected by copyright. All rights reserved.

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ASCT2 defined by enzyme-mediated activation of radical sources enhances malignancy of GD2-plus small cell lung cancer

Abstract

Ganglioside GD2 is specifically expressed in small cell lung cancer (SCLC) cells, leading to enhancement of malignant phenotypes, such as cell proliferation and migration. However, how GD2 promotes malignant phenotypes in SCLC cells is not well known. In this study, to reveal mechanisms by which GD2 increases malignant phenotypes in SCLC cells, we performed enzyme-mediated activation of radical sources combined with mass spectrometry in GD2 positive (+) SCLC cells. Consequently, we identified ASC amino-acid transporter 2 (ASCT2), a major glutamine transporter, which coordinately works with GD2. We showed that ASCT2 was highly expressed in glycolipid-enriched microdomain/rafts in GD2(+) SCLC cells, and co-localized with GD2 in proximity ligation assay and immunocytostaining, and bound with GD2 in immuneoprecipitation/TLC-immunostaining. Malignant phenotypes of GD2(+) SCLC cells were enhanced via glutamine uptake, and were suppressed by L-γ-glutamyl-p-nitroanilide, a specific inhibitor of ASCT2, via reduced phosphorylation of p70 S6K1 and S6. These results suggested that ASCT2 enhances glutamine uptake in GEM/rafts in GD2(+) SCLC cells, leading to the enhancement of cell proliferation and migration through increased phosphorylation of mTORC1 signaling axis.

This article is protected by copyright. All rights reserved.

http://ift.tt/2mDPSBA

Detection of CTCs in cervical cancer using a conditionally replicative adenovirus targeting telomerase-positive cells

Abstract

Circulating tumor cells (CTCs) are newly discovered biomarkers of cancers. Although many systems detect CTCs, a gold standard has not yet been established. We analyzed CTCs in uterine cervical cancer patients using an advanced version of conditionally replicative adenovirus targeting telomerase-positive cells, which was enabled to infect coxsackievirus-adenovirus receptor-negative cells and to reduce false-positive signals in myeloid cells. Blood samples from cervical cancer patients were hemolyzed and infected with the virus and then labeled with fluorescent anti-CD45 and anti-pan cytokeratin antibodies. GFP (+)/CD45 (−) cells were isolated and subjected to whole-genome amplification followed by polymerase chain reaction analysis of human papillomavirus (HPV) DNA. CTCs were detected in 6 of 23 patients with cervical cancers (26.0%). The expression of CTCs did not correlate with the stage of cancer or other clinicopathological factors. In 5 of the 6 CTC-positive cases, the same subtype of HPV DNA as that of the corresponding primary lesion was detected, indicating that the CTCs originated from HPV-infected cancer cells. These CTCs were all negative for cytokeratins. The CTCs detected by our system were genetically confirmed. CTCs derived from uterine cervical cancers had lost epithelial characteristics, indicating that epithelial marker-dependent systems do not have the capacity to detect these cells in cervical cancer patients.

This article is protected by copyright. All rights reserved.

http://ift.tt/2zhuNCQ

Clinical significance of disease-specific MYD88 mutations in circulating DNA in primary central nervous system lymphoma

Abstract

Recent sequencing studies demonstrated the MYD88 L265P mutation in more than 70% of primary central nervous system lymphomas (PCNSL), and the clinical significance of this mutation has been proposed as diagnostic and prognostic markers in PCNSL. On the other hand, mutational analyses using cell-free DNAs have been reported in a variety of systemic lymphomas. To investigate how sensitively the MYD88 L265P mutation can be identified in cell-free DNA from PCNSL patients, we performed droplet digital PCR (ddPCR) and targeted deep sequencing (TDS) in consecutive 14 PCNSL patients from whom paired tumor-derived DNA and cell-free DNA was available at diagnosis. The MYD88 L265P mutation was found in tumor-derived DNA from all 14 patients (14/14, 100%). In contrast, among 14 cell-free DNAs evaluated by ddPCR (14/14) and TDS (13/14), MYD88 L265P mutation was detected in eight out of 14 (ddPCR) and 0 out of 13 (TDS) samples, implying dependence on the detection method. After chemotherapy, the MYD88 L265P mutation in cell-free DNAs was traced in five patients; unexpectedly, the mutations disappeared after the chemotherapy was given, and they remained undetectable in all patients. These observations suggest that ddPCR can sensitively detect the MYD88 L265P mutation in cell-free DNA and could be used as non-invasive diagnostics, but may not be applicable for monitoring minimal residual diseases in PCNSL.

This article is protected by copyright. All rights reserved.

http://ift.tt/2mKxTK2

Impact of chemotherapy-induced neutropenia (CIN) and febrile neutropenia (FN) on cancer treatment outcomes: An overview about well-established and recently emerging clinical data

Publication date: December 2017
Source:Critical Reviews in Oncology/Hematology, Volume 120
Author(s): Yassine Lalami, Jean Klastersky
Despite the overwhelming evidence for the role of granulocyte colony stimulating factors (G-CSF) in managing febrile neutropenia (FN) risk, chemotherapy-induced neutropenia (CIN) and/or FN still remain the most common reasons for reducing relative dose intensity (RDI) and/or delaying chemotherapy schedule. The need to maintain RDI to ensure optimal clinical outcomes is one of the key rationales for utilizing G-CSF. There is a high incidence of reduced RDI in both curative and palliative settings, and this observation is especially evidenced in retrospective analyses. Reduced RDI leads to significantly decreased survival outcomes and quality of life in various malignancies at various clinical settings and stages.Beyond its role as a surrogate prognostic marker, high-grade CIN may have an unexpected predictive role in clinical practice, as illustrated by several data relating CIN occurrence with favorable survival outcomes; this may be due to the fact that body surface area (BSA) – based calculation of dose may not fully account for the pharmacokinetics (PK) of cytotoxic drugs and the fact that there may be variability in drug metabolism between patients treated with same chemotherapy regimens.



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