Pancreatic ductal adenocarcinoma is one of the deadliest carcinomas and is characterized by highly tumorigenic and metastatic cancer stem cells (CSC). CSCs evade available therapies, which ...preferentially target highly proliferative and more differentiated progenies, leaving behind CSCs as a putative source for disease relapse. Thus, to identify potentially more effective treatment regimens, we screened established and new compounds for their ability to eliminate CSCs in primary pancreatic cancer (stem) cells in vitro and corresponding patient-derived pancreatic cancer tissue xenografts in vivo. Intriguingly, we found that in vitro treatment with the antimalarial agent chloroquine significantly decreased CSCs, translating into diminished in vivo tumorigenicity and invasiveness in a large panel of pancreatic cancers. In vivo treatment in combination with gemcitabine was capable of more effectively eliminating established tumors and improved overall survival. The inhibitory effect of chloroquine was not related to inhibition of autophagy, but was due to inhibition of CXCL12/CXCR4 signaling, resulting in reduced phosphorylation of ERK and STAT3. Furthermore, chloroquine showed potent inhibition of hedgehog signaling by decreasing the production of Smoothened, translating into a significant reduction in sonic hedgehog-induced chemotaxis and downregulation of downstream targets in CSCs and the surrounding stroma. Our study demonstrates that via to date unreported effects, chloroquine is an effective adjuvant therapy to chemotherapy, offering more efficient tumor elimination and improved cure rates. Chloroquine should be further explored in the clinical setting as its success may help to more rapidly improve the poor prognosis of patients with pancreatic cancer.
Rare cells not normally present in the peripheral bloodstream, such as circulating tumour cells, have potential applications for development of non‐invasive methods for diagnostics or follow up. ...Obtaining these cells however require some means of discrimination, achievable by cell type specific antibodies. Here we have generated a microselection method allowing antibody selection, by phage display, targeting a single cell in a heterogeneous population. One K562 cell (female origin) was positioned on glass slide among millions of lymphocytes from male donor, identifying the K562 cell by FISH (XX). Several single cell selections were performed on such individual slides. The phage particles bound to the target cell is protected by a minute disc, while inactivating all remaining phage by UV‐irradiation; leaving only the phage bound to the target cell viable. We hereby retrieved up to eight antibodies per single cell selection, including three highly K562 cell type specific.
Highlights • There is a paucity of tumor-associated antigens for antibody targeting in oncology. • Phage antibody libraries are available for the generation of therapeutic antibodies. • Advanced ...selection conditions allow ex vivo selection of anticancer antibodies. • There is no technology for antigen profiling of intact tumors • Sequential ex vivo and in vivo phage selection allows the selection of tumor-homing antibodies.
: Accumulation of posttranslationally damaged proteins during aging could explain the decline of cell performance with age. Nɛ‐carboxymethyllysine (CML) is the major glycation product on damaged ...proteins, causing dysfunction and cross‐linking. The proteasome, a multicatalytic degradation complex, is one of the pathways for eliminating damaged proteins, and thus regulating their accumulation within the cell. However, the proteinase activities of the proteasome decline during aging. This may be due to posttranslational modifications of the subunits forming the proteasome complex. Using phage display technology, we have selected 16 single‐chain variable fragments (scFv) recognizing the CML‐modified α7 subunit of the proteasome. Using one of them, Ab3, we have observed a five‐fold increase of CML‐α7 in old human skin fibroblasts in comparison with young fibroblasts and telomerase‐immortalized bone marrow cells (hTERT‐BMCs).
Here we describe a new method applying phage-displayed antibody libraries to the selection of antibodies against a single identified cell on a glass slide. This is the only described method that has ...successfully achieved selection of antibodies against a single rare cell in a heterogeneous population of cells. The phage library is incubated with the slide containing the identified rare cell of interest; incubation is followed by UV irradiation while protecting the target cell with a minute disc. The UV light inactivates all phages outside the shielded area by cross-linking the DNA constituting their genomes. The expected yield is between one and ten phage particles from a single cell selection. The encoded antibodies are subsequently produced monoclonally and tested for specificity. This method can be applied within a week to carry out ten or more individual cell selections. Including subsequent testing of antibody specificity, a specific antibody can be identified within 2 months.
The previously unknown coronavirus that caused severe acute respiratory syndrome (SARS-CoV) affected more than 8,000 persons worldwide and was responsible for more than 700 deaths during the first ...outbreak in 2002-2003. For reasons unknown, the SARS virus is less severe and the clinical progression a great deal milder in children younger than 12 years of age. In contrast, the mortality rate can exceed 50% for persons at or above the age of 60. As part of the Sino-European Project on SARS Diagnostics and Antivirals (SEPSDA), an immune phage-display library is being created from convalescent patients in a phagemid system for the selection of single-chain fragment variables (scFv) antibodies recognizing the SARS-CoV.
Severe Acute Respiratory Syndrome (SARS) SØRENSEN, MORTEN DRÆBY; SØRENSEN, BRIAN; GONZALEZ-DOSAL, REGINA ...
Annals of the New York Academy of Sciences,
05/2006, Letnik:
1067, Številka:
1
Journal Article
Recenzirano
Odprti dostop
: The previously unknown coronavirus that caused severe acute respiratory syndrome (SARS‐CoV) affected more than 8,000 persons worldwide and was responsible for more than 700 deaths during the first ...outbreak in 2002–2003. For reasons unknown, the SARS virus is less severe and the clinical progression a great deal milder in children younger than 12 years of age. In contrast, the mortality rate can exceed 50% for persons at or above the age of 60. As part of the Sino‐European Project on SARS Diagnostics and Antivirals (SEPSDA), an immune phage‐display library is being created from convalescent patients in a phagemid system for the selection of single‐chain fragment variables (scFv) antibodies recognizing the SARS‐CoV.
Antibody based drugs represent one of the most successful and promising therapeutic approaches in oncology. Large combinatorial phage antibody libraries are available for identification of ...therapeutic antibodies, and a variety of technologies exist for their further conversion into multivalent and multispecific formats optimized for the desired pharmacokinetics and the pathological context. However, there is no technology for antigen profiling of intact tumors to identify tumor markers targetable with antibodies. Such constraints have led to a relative paucity of tumor-associated antigens for antibody targeting in oncology. Here we review novel approaches aimed at the identification of antibody-targetable, accessible antigens in intact tumors. We hope that such advanced selection approaches will be useful in the development of next-generation antibody therapeutics for cancer.
: Studies suggest that the region around microsatellite marker D4S1564 on chromosome 4 is in some way linked to longevity. As a part of the integrated European project Genetics of Healthy Aging ...(GeHA), we set out to investigate the genes found in this region using a proteomics approach. Here, we report the cloning of six candidate genes.
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