KDM5B predicts temozolomide-resistant subclones in glioblastoma

Adaptive plasticity to the standard chemotherapeutic temozolomide (TMZ) leads to glioblastoma progression. Here, we examine early stages of this process in patient-derived cellular models, exposing the human lysine-specific demethylase 5B (KDM5B) as a prospective indicator for subclonal expansion. By integration of a reporter, we show its preferential activity in rare, stem-like ALDH1A1+ cells, immediately increasing expression upon TMZ exposure. Naive, genetically unmodified KDM5Bhigh cells phosphorylate AKT (pAKT) and act as slow-cycling persisters under TMZ. Knockdown of KDM5B reverses pAKT levels, simultaneously increasing PTEN expression and TMZ sensitivity. Pharmacological inhibition of PTEN rescues the effect. Interference with KDM5B subsequent to TMZ decreases cellular vitality, and clonal tracing with DNA barcoding demonstrates high individual levels of KDM5B to predict subclonal expansion already before TMZ exposure. Thus, KDM5Bhigh treatment-naive cells preferentially contribute to the dynamics of drug resistance under TMZ. These findings may serve as a cornerstone for future biomarker-assisted clinical trials.

Statins affect cancer cell plasticity with distinct consequences for tumor progression and metastasis

Statins are among the most commonly prescribed drugs, and around every fourth person above the age of 40 is on statin medication. Therefore, it is of utmost clinical importance to understand the effect of statins on cancer cell plasticity and its consequences to not only patients with cancer but also patients who are on statins. Here, we find that statins induce a partial epithelial-to-mesenchymal transition (EMT) phenotype in cancer cells of solid tumors. Using a comprehensive STRING network analysis of transcriptome, proteome, and phosphoproteome data combined with multiple mechanistic in vitro and functional in vivo analyses, we demonstrate that statins reduce cellular plasticity by enforcing a mesenchymal-like cell state that increases metastatic seeding ability on one side but reduces the formation of (secondary) tumors on the other due to heterogeneous treatment responses. Taken together, we provide a thorough mechanistic overview of the consequences of statin use for each step of cancer development, progression, and metastasis.

Unraveling Tumor Heterogeneity by Using DNA Barcoding Technologies to Develop Personalized Treatment Strategies in Advanced-Stage PDAC

Tumor heterogeneity is a hallmark of many solid tumors, including pancreatic ductal adenocarcinoma (PDAC), and an inherent consequence of the clonal evolution of cancers. As such, it is considered the underlying concept of many characteristics of the disease, including the ability to metastasize, adapt to different microenvironments, and to develop therapy resistance. Undoubtedly, the high mortality of PDAC can be attributed to a high extent to these properties. Despite its apparent importance, studying tumor heterogeneity has been a challenging task, mainly due to its complexity and lack of appropriate methods. However, in recent years molecular DNA barcoding has emerged as a sophisticated tool that allows mapping of individual cells or subpopulations in a cell pool to study heterogeneity and thus devise new personalized treatment strategies. In this review, we provide an overview of genetic and non-genetic inter- and intra-tumor heterogeneity and its impact on (personalized) treatment strategies in PDAC and address how DNA barcoding technologies work and can be applied to study this clinically highly relevant question.

Altered Mitochondria Functionality Defines a Metastatic Cell State in Lung Cancer and Creates an Exploitable Vulnerability

Lung cancer is a prevalent and lethal cancer type that leads to more deaths than the next four major cancer types combined. Metastatic cancer spread is responsible for most cancer-related deaths but the cellular changes that enable cancer cells to leave the primary tumor and establish inoperable and lethal metastases remain poorly understood. To uncover genes that are specifically required to sustain metastasis survival or growth, we performed a genome-scale pooled lentiviral-shRNA library screen in cells that represent nonmetastatic and metastatic states of lung adenocarcinoma. Mitochondrial ribosome and mitochondria-associated genes were identified as top gene sets associated with metastasis-specific lethality. Metastasis-derived cell lines in vitro and metastases analyzed ex vivo from an autochthonous lung cancer mouse model had lower mitochondrial membrane potential and reduced mitochondrial functionality than nonmetastatic primary tumors. Electron microscopy of metastases uncovered irregular mitochondria with bridging and loss of normal membrane structure. Consistent with these findings, compounds that inhibit mitochondrial translation or replication had a greater effect on the growth of metastasis-derived cells. Finally, mice with established tumors developed fewer metastases upon treatment with phenformin in vivo. These results suggest that the metastatic cell state in lung adenocarcinoma is associated with a specifically altered mitochondrial functionality that can be therapeutically exploited. SIGNIFICANCE: This study characterizes altered mitochondria functionality of the metastatic cell state in lung cancer and opens new avenues for metastasis-specific therapeutic targeting.

Operating the European Drawer Rack on the ISS

The Erasmus User Centre, located at ESTEC in Noordwijk, will have overall responsibility for the preparation and execution of operations for the European Drawer Rack (EDR) facility in the European Columbus laboratory on the International Space Station (ISS). Together with the national User Support and Operations Centres (USOCs) involved in the operation of experiments on the ISS, it will form the network conducting the decentralised payload operations baselined for the European elements of the ISS.

[Bronchopulmonary cancer, antiphospholipid syndrome and coagulation disorders]

INTRODUCTION

The antiphospholipid syndrome includes recurrent thrombotic manifestations related to antiphospholipid antibodies. Adrenal insufficiency is a rare complication of the antiphospholipid syndrome.

EXEGESIS

We report a case of acute adrenal insufficiency secondary to bilateral adrenal hemorrhage in a 45-year-old man. The finding of antiphospholipid antibodies and 6 months later of a polymetastatic bronchopulmonary cancer led us to diagnose a paraneoplasic antiphospholipid syndrome.

CONCLUSION

We discuss the role of coagulation disorders in the pathogenesis of tumor growth and rapid metastatic spread. Assessment of the high risk for thrombosis may be of prognostic and therapeutic value in patients with evolutive bronchopulmonary cancer. Early anticoagulation treatment in association with classical treatment of cancer may contribute to prevent malignant process from extending and avoid metastatic spread.

[Cancer in patients infected with the human immunodeficiency virus. The unusual aspects]

CANCER AND HIV INFECTION: As the HIV epidemic advances, the spectrum of non-AIDS defining malignancy is expanding. Recent reports suggest an increased incidence of skin cancers, squamous cell carcinomas of the anus, and Hodgkin's disease in HIV-infected patients. Other neoplasms encountered in this setting include oral mucosa, head and neck carcinoma without evidence of increased incidence. PARTICULAR FEATURES: The natural history of lung, testicle and skin cancer (excepting Kaposi sarcoma) as well as ENT cancer appears to be modified in HIV-infected patients. The main problem raised by these tumors is confounding infection which may lead to late diagnosis or an error in tumor staging.

[Tyrosine kinase: implications in tumor pathology and therapeutic perspectives]

The tyrosine kinase family includes growth factor receptor and cytoplasmic enzymes. It plays a key role in normal cell division and abnormal cell proliferation and differentiation. The most common tyrosine kinases are the epidermal-growth factor (EGFR) and platelet-derived growth factor (PDGF) receptors, and a chromosome Philadelphia product, the Bcr-abl oncogene. Many studies have attempted to correlate clinical evolution of tumors with tyrosine kinase expression. However, clinical application of these new prognostic factors has not yet been demonstrated. More recently, tyrosine-phosphorylation inhibitors (tryphostin) have been developed in phase I studies. Results that were obtained show some objective responses in patients with glioblastoma and polymetastatic cancer. Another approach to block tyrosine kinase expression is the use of monoclonal antibodies. Trials using such antibodies have shown interesting preliminary results.

[Hypercalcemia associated with hyperleukocytosis, a new paraneoplastic syndrome]

BACKGROUND

The association of hypercalcemia and leukocytosis constitutes a novel paraneoplastic syndrome rarely reported in the course of head and neck and lung squamous cell carcinoma. We report 7 new cases.

CASE REPORTS

In 5 cases the diagnosis was well-differentiated squamous cell carcinoma, in 1 differentiated non-small-cell carcinoma and in 1 adenocarcinoma of unknown origin. There was no argument favoring hyperparathyroidism in any of the cases. Microbiology tests were negative and large spectrum antibiotics were unsuccessful, eliminating an associated infection as cause of the leukocytosis.

DISCUSSION

This association probably involves the secretion of hematopoietic growth factors such as G-CSF or GM-CSF by the tumor, acting simultaneously on osteoclasts and granulomonocytic cells which have common precursers.

[Lung cancer in patients infected with human immunodeficiency virus. Clinical course and therapeutic implications]

OBJECTIVES

HIV infection is associated with increased frequency of non-Hodgkin's lymphoma and Kaposi sarcoma. Like other malignancies, lung cancer has been described in HIV-infected patients although no evidence of a statistical correlation has been reported.

PATIENTS AND METHODS

We performed a retrospective analysis of 15 HIV-infected patients with lung cancer. The patients were relatively younger (mean age 45 years) than is commonly found in lung cancer cohorts.

RESULTS

The 15 patients had mild immunodepression (240 CD4+/mm3) and were in advanced clinical stage at diagnosis. Mean overall survival was 6 months and no clinical or biological prognostic factors were found. Death was usually due to infection, suggesting a synergetic effect between HIV and chemotherapy-induced immunodepression.

CONCLUSION

We propose early antiretroviral therapy in cases of chemotherapy-treated HIV patients, even when commonly accepted immunological and/or clinical criteria are absent.

[Hyponatremia during treatment with cisplatin]

BACKGROUND

Cisplatin is one of the most widely used agents in cancer treatment. Cisplatin regimens can lead to a more or less pronounced hyponatremia in 4 to 10% of cases due to salt wasting with hypomagnesemia and normokaliemia. Functional and renal failure and orthostatic hypotension can be observed.

CASE REPORT

A 54-year-old woman with brain metastases of a non-small-cell lung cancer was given a chemotherapy regimen containing cisplatin. Hyponatremia with confusion occurred after each cisplatin perfusion. The diagnosis retained was cisplatin-induced salt wasting. The patient was given salt prolonged supplementation and carboplatin was substituted for cisplatin in the chemotherapy regimen.

DISCUSSION

Hyponatremia frequently occurs in cancer patients. Cisplatin-induced hyponatremia requires specific management. Treatment is based on sodium intake which sometimes takes several months to replete stores. Carboplatin can be used instead of cisplatin in case of major hyponatremia.

Pseudoaneurysm of the inferior epigastric artery

Abdominal wound closure with safety retention sutures can cause intestinal obstruction, fistula, skin necrosis and rarely pseudoaneurysms of the inferior epigastric artery (IEA) (1, 2, 3). We report the case of a man presenting with a pseudoaneurysm of the IEA after traumatic extraction of retention sutures, successfully treated by surgical ligation of the feeding vessels. The importance of contrast enhanced CT and duplex colour Doppler sonography in differential diagnosis of postoperative abdominal wall masses is discussed, as well as possibilities and risks in the treatment of false aneurysms of the IEA.

[Spinal cord compression of sarcoidosis origin: a case]

This observation reports the case of a rapid paraparesia occurring in a young man. Imaging disclosed a spina tumor. Diagnosis of sarcoidosis leads us to suspect a specific spinal granuloma involvement and to start corticosteroid pulses. Clinical and radiological symptoms improved dramatically.

[Edwardsellia tarda septicemia in chronic lymphoid leukemia]

Edwardsiella tarda is a Gram negative bacilli. At least 300 cases have been reported in the literature. Here we report a new case of Edwardsiella tarda septicemia in an immunocompromised patient with chronic lymphocytic leukemia. Chief infections associated with this bacterium include bacterial gastroenteritis and septicemia with fatal evolution in 50% of cases. Risk factors associated with Edwardsiella tarda infections include exposure to aquatic environments and exotic animals. Although studies indicate that this bacterium is susceptible to most commonly prescribed antibiotics, it is interesting to note that in our case, Edwardsiella tarda was resistant to numerous beta-lactamins.

[A nidulans bronchial aspergillosis after treatment of low-grade lymphoma with fludarabine]

Pulmonary aspergillosis is a common complication in neutropenic patients. The most important fungus is Aspergillus fumigatus. We report a case of invasive pulmonary aspergillosis due to Aspergillus nidulans secondary to fludarabine therapy. There are few cases of pulmonary aspergillosis due to Aspergillus nidulans (one chronic necrotizing pulmonary aspergillosis, one aspergilloma). Fludarabine induces a marked decreased of CD4 lymphocyte count responsible for opportunistic infections. It is the first case of aspergillosis after fludarabine therapy and the occurrence of such infection must be considered after purine analog therapy.

Liver biopsy is not useful in the diagnosis of mycobacterial infections in patients who are infected with human immunodeficiency virus

Liver biopsy (LB) has been advocated for the detection of mycobacterial infections in patients infected with human immunodeficiency virus (HIV). To determine the effect of the use of this procedure on survival, we compared it terms of yield with histological findings and noninvasive microbiological procedures. We reviewed the cases of 98 patients who underwent 106 LBs as part of the diagnostic screening for fever of unknown origin. LB revealed 17 cases of mycobacterial infection. For all but one patient, the results of at least one noninvasive procedure were positive. In 85 cases where infections were not diagnosed by LB, 17 had infections documented by other procedures. When all culture results are considered, the mean (+/- SD) incubation time to the first positive culture was 15 +/- 5 days, whereas the mean (+/- SD) incubation time to the first positive culture of an LB specimen was 28 +/- 9 days. The survival time was not significantly increased for patients who underwent LB and had positive Ziehl-Neelsen-stained smears; these patients survived a mean (+/- SD) of 12 +/- 11 months, whereas patients with negative smears survived a mean (+/- SD) of 9 +/- 10 months. Noninvasive studies are preferable to LB for the diagnosis of mycobacterial infections in HIV-infected patients.

[Comparative profitability of hepatic biopsy and microbiological tests in patients with HIV infection]

OBJECTIVES

Diagnostic liver biopsy is proposed in HIV-positive patients who present unexplained fever. This invasive procedure is truly useful if it allows establishing a difficult diagnosis or improves survival rate. We conducted a retrospective study to determine the diagnostic and prognostic power of liver biopsy in HIV-positive patients with fever.

METHODS

One hundred thirty-eight liver biopsies were performed in 129 patients. Utility was defined as demonstration of the pathogen or identification of a tumoral process.

RESULTS

The liver biopsy met the utility criteria in 27 cases showing mycobacterial infections (n = 22) and herpes hepatitis, type 1 herpes simplex virus, cytomegalovirus and cryptococcosis infections (n = 1 each). These last 4 diagnoses were also possible with other tests. Comparing non-contributive liver biopsies (n = 111) with those demonstrating hepatic mycobacterial infection (n = 22) showed that the two groups were not different in terms of demographic data. Splenomegalia was more frequent in the non-contributive group (68% vs 37%, p = 0.007) as was superficial lymph node enlargement (45% vs 12%, p < 10(-3)). Laboratory tests were not discriminating. Mycobacterial infection was diagnosed in 22 patients in the non-contributive group. Bacteriological samples were positive for mycobacterium in 20 of the 22 patients in the contributive group. The mean delay to the first positive test for mycobacterium was 15 +/- 8 days compared with 30 +/- 10 days for liver tissue cultures. Mean survival after liver biopsy was 10 months: patients with a positive Ziehl-Neelson stain on the liver biopsy did not have a longer survival (9.7 +/- 7.6 vs 10.2 +/- 10.4 months).

CONCLUSION

In most cases, liver biopsy in HIV-positive patients with fever provides a diagnosis which can be obtained with non-invasive techniques without improving prognosis.

[Rhodococcus equi infection in AIDS: a case with pulmonary abscess. Review of the literature]

Rhodococcus equi is an easily missed opportunistic infection in patient infected by the human immunodeficiency virus. We report one case with lung abscess in a patient with AIDS with literature review.

Recurrent cytogenetic abnormalities observed in complete remission of acute myeloid leukemia do not necessarily mark preleukemic cells

We have undertaken the cytogenetic monitoring of 39 adult patients treated for de novo acute myeloid leukemia (AML) by intensive chemotherapy. We describe this monitoring in seven patients in continuous complete clinical and morphologic remission (CR) of AML. Although in CR, these patients exhibit the emergence of cytogenetically abnormal clones. Abnormalities observed include monosomy 7, del(20)(q11), partial trisomy 1q, and 6p12-22 rearrangements. They correspond to well-known chromosomal rearrangements commonly found in myelodysplasia (MDS), and myeloproliferative syndromes (MPS), as well as AML. Present as the sole detected chromosomal change, they preceded by months the onset of overt leukemia or MDS. In some cases, the abnormal clone showed a proliferative advantage (some patients exhibited up to 100% of abnormal bone marrow metaphases in subsequent analyses). AML relapse, when it occurred, was associated with a different chromosomal modification. Altogether the question arises, whether the abnormalities pointed out in our study (monosomy 7, del(20)(q11), partial trisomy for the long arm of chromosome 1 (q21qter), 6p12-22 rearrangements), and seen after chemotherapy, mark preleukemic cells or not, and whether they participate indirectly, or not at all in the leukemic process.