Begell House Inc.
Onco Therapeutics
OT
2694-4642
2
2
2011
FIRST INTERNATIONAL WORKSHOP ON "ROLES OF RKIP IN TUMOR CELL SENSITIZATION TO APOPTOSIS AND PROGNOSTIC SIGNIFICANCE"Held in Los Angeles, California, March 19−20, 2010GUEST EDITORS:BENJAMIN BONAVIDA, FAHD AL-MULLA, & KAM C. YEUNG
v-viii
10.1615/ForumImmunDisTher.v2.i2.10
The First International Workshop on "Roles of RKIP in Tumor Cell Sensitization to Apoptosis and Prognostic Significance" was held at the University of California at Los Angeles, March 19−20, 2010. This workshop was focused on the current status of the various functions assigned to RKIP and its pivotal role in the regulation of cancer cells’ survival and response to therapies. The workshop was attended by national and international experts. The topics presented included the role of RKIP in the regulation of cell survival, cell proliferation, cell response to growth factors, metastasis, and sensitivity to chemotherapy and immunotherapy, as well as its prognostic significance and its role as a new target for therapeutic intervention. Issue 2 of volume 2 is the second in a two-part series of publications of the workshop proceedings. This volume is the first to publish manuscripts and reviews on RKIP and serves as an important reference for scientists, clinicians, and students.
Effects of RKIP Loss in Human and in Animal Models of Colorectal Cancer
111-118
10.1615/ForumImmunDisTher.v2.i2.20
Brendan
Doyle
Beatson Institute for Cancer Research, Glasgow, UK
Suzanne
Hagan
Department of Vision Sciences, Glasgow Caledonian University, Glasgow, UK
Lucy
Scott
Centre for Oncology and Applied Pharmacology, University of Glasgow, UK
Owen
Sansom
Beatson Institute for Cancer Research, Glasgow, UK
Walter
Kolch
Systems Biology Ireland, University College Dublin, Belfield, Dublin 4, Ireland; Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland; School of Medicine and Medical Science, University Colle
RKIP
colorectal cancer
prognostic marker
mouse model
Raf kinase inhibitor protein (RKIP) has been shown to be differentially regulated in a number of different human cancers. Typically, RKIP levels are found to be lower in tumor tissue than in normal tissue, and lower still in tumor metastases. In colorectal cancer (CRC), this is also the case; however interestingly in this disease, it has also been shown that the level of RKIP in the primary tumor correlates inversely with both the likelihood of metastatic relapse and with prognosis. Although this relationship with prognosis has clear clinical relevance, there is also some evidence that RKIP may provide even greater utility by acting as a predictive marker. In this review, we describe the evidence demonstrating the clear role for RKIP as a prognostic marker in CRC and go on to describe some of our evidence indicating a possible predictive role. Because there is as yet no mechanistic understanding of how low levels of RKIP affect prognosis in CRC, we have been using the RKIP knockout mouse to attempt to address this question. Here, we describe the current literature relating to the RKIP knockout mouse and our approach to using it to study the role of RKIP in CRC.
Induction of RKIP Expression by Anticancer Therapeutic Antibodies and Its Role in the Reversal of Chemo- and Immunoresistance
119-126
10.1615/ForumImmunDisTher.v2.i2.30
Benjamin
Bonavida
Department of Microbiology, Immunology, &
Molecular Genetics, David Geffen School of Medicine at UCLA, Johnson Comprehensive Cancer Center, University of California at Los Angeles, Los Angeles, CA 90025-1747, USA
rituximab
BM-ca
LFB-R603
galiximab
resistance
sensitization
apoptosis
B-NHL
biomarker
Raf-1 kinase inhibitor protein (RKIP)
Immunotherapy against human cancers has gained momentum after a long silence. Both cell-mediated and antibody-mediated therapies have been utilized with successful clinical responses. The first antibody that is targeted and FDA approved is rituximab, a chimeric anti-CD20 monoclonal antibody (mAb) for the treatment of B non-Hodgkin’s lymphoma (B-NHL), both as a single agent and in combination with CHOP. Over 20 mAbs have been subsequently developed and approved by the FDA in the treatment of a variety of solid and hematological malignancies. The mechanisms underlying antibody-mediated therapeutic effects have been postulated to consist of antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC), and seldom direct apoptosis. Earlier studies with rituximab demonstrated that in addition to above mechanisms, cell signaling takes place following rituximab interaction with CD20, leading to inhibition of intracellular survival and antiapoptotic pathways. These inhibitory effects were shown to be responsible, in large part, for rituximab-mediated sensitization to apoptosis by both chemotherapeutic and immunotherapeutic drugs. Similar findings shown with rituximab were also observed with other anti-CD20 mAbs and with galiximab (humanized anti-CD80 mAb). Rituximab and other anti-CD20 mAbs as well as galiximab were shown, following treatment with B-NHL cells, to induce and upregulate Raf-1 kinase inhibitor protein (RKIP) expression. The induction of RKIP was the result, in part, of antibody-mediated inhibition of the constitutively activated NF-κB pathway and downstream inhibition of the RKIP transcription repressor Snail. The antibody-mediated induction of RKIP plays a pivotal role in the sensitization and reversal of tumor cell resistance. The induction of RKIP by therapeutic antibodies may serve as a marker for clinical response and reversal of resistance when the therapeutic antibody is used in combination with cytotoxic drugs. Likewise, failure to induce RKIP by the antibody may suggest failure of a clinical response by the combination treatment of antibody and drugs. Furthermore, it is proposed that levels of RKIP expression may be of prognostic significance, and RKIP may be considered as a target for therapeutic intervention in hematological malignancies.
Induction of Apoptosis and Chemosensitization by the Histone Deacetylase Inhibitor Trichostatin in Hepatocellular Carcinoma Cells: Molecular Analysis and RKIP Levels
127-135
10.1615/ForumImmunDisTher.v2.i2.40
Luigi
Inguglia
Department STEBICEF, University of Palermo, Palermo, Italy; Euro Mediterranean Institute of Science and Technology (IEMEST), Palermo, Italy
Monica
Notarbartolo
Pharmacology Unit, Department of Health Sciences and Mother and Child Care "G. D'Alessandro", University of Palermo; Palermo, Italy
Paola
Poma
Pharmacology Unit, Department of Health Sciences and Mother and Child Care "G. D'Alessandro", University of Palermo; Department of Biological, Chemical and Pharmaceutical Science and Technology (STEBICEF), University of Palermo, Palermo, Italy
Manuela
Labbozzetta
Pharmacology Unit, Department of Health Sciences and Mother and Child Care "G. D'Alessandro", University of Palermo; Department of Biological, Chemical and Pharmaceutical Science and Technology (STEBICEF), University of Palermo, Palermo, Italy
Natale
D'Alessandro
Pharmacology Unit, University of Palermo Department of Health Sciences and Mother and Child Care "Giuseppe D'Alessandro" Palermo, Italy
hepatocellular carcinoma
Raf-1 kinase inhibitor protein
Yin Yang 1
gene expression
histone deacetylase inhibitor
trichostatin
apoptosis
chemosensitization
The mRNA and protein levels of RKIP are reduced and those of YY1 increased in clinical HCC. Loss, mutation, or promoter hypermethylation of the RKIP gene may not account for the downregulation of RKIP in HCC. Histone deacetylation can silence gene expression and play a significant role in hepatocarcinogenesis. The histone deacetylase inhibitor (HDACI) trichostatin induced cell growth inhibition and proapoptotic effects in HA22T/VGH and HepG2 HCC cells; it also exhibited synergy with doxorubicin. Treatment with trichostatin caused histone hyperacetylation and down- or upregulated expression of different genes (such as β-catenin, cyclin D1, hTERT, XIAP, and IL-6). These changes might, at least in part, explain the anticancer and chemosensitizing activities of trichostatin. Nevertheless, trichostatin did not modify RKIP or YY1 mRNA and protein levels in the two representative HCC cell lines. Although further studies are necessary to clarify the possible role of epigenetic changes in the expression of RKIP and YY1, our results underline the therapeutic potential of HDACIs in HCC.
Role of RKIP in Sensitizing Tumor Cells to Photodynamic Therapy
137-143
10.1615/ForumImmunDisTher.v2.i2.50
Valentina
Rapozzi
Department of Medicine, University of Udine, 33100 Udine, Italy
Kazuo
Umezawa
Department of Molecular Target Medicine Screening Aichi Medical University School of Medicine, Nagakute, Aichi, Japan
Luigi E.
Xodo
Department of Biomedical Sciences and Technologies, School of Medicine, University of Udine, Italy
photodynamic therapy
pheophorbide a
nitric oxide
NF-kB
Snail
RKIP
DHMEQ
Photodynamic therapy (PDT) combines the administration of a photosensitizer to a tumor and irradiation with nonthermal light to generate cytotoxic reactive oxygen species. The efficacy of the treatment depends on a number of factors including the properties of the photosensitizer, light dosage, and type of the target cells. In general, although PDT is an efficacious treatment modality, in some cases, the risk of recurrence is underestimated; thus, there is interest to improve the activity of PDT. We have recently focused on the photosensitizing properties of pheophorbide a (Pba), a chlorophyll derivative. At high-dose PDT (Pba > IC50), the growth of tumor cells is completely arrested by apoptosis and/or necrosis, while at low dose (Pba < IC50), the photosensitizer causes a temporary growth arrest followed by cell recovery. Because Pba/PDT stimulates, in a dose-dependent manner, the production of nitric oxide (NO) and NO is known to inhibit the NF-κB path-way, which is involved in the NF-κB/Snail/RKIP loop, we evaluated if the tumor cells can be sensitized to PDT by the NO-mediated inhibition of NF-κB and the concomitant activation of the RKIP proapoptotic gene. Our preliminary findings are presented.
Development and Application of Tissue Microarrays for Biomarker Studies
145-159
10.1615/ForumImmunDisTher.v2.i2.60
Erin
Maresh
Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
Vei H.
Mah
Department of Human Genetics, University of California at Los Angeles, Los Angeles, CA 90095; Department of Medicine, Division of Hematology-Oncology, UCLA David Geffen School of Medicine, Los Angeles,
CA
Mohammad
Alavi
Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
Angela
Presson
Department of Biostatistics, UCLA School of Public Health, Los Angeles, CA, USA
Lora
Bagryanova
Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
Nam K.
Yoon
Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
George
Chang
Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
Yahya
Elshimali
Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
Linda
Shevlin
Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
Lily
Zhang
Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
Longsheng
Hong
Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
Samson
Schatz
Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
Ai
Li
Department of Biostatistics, UCLA School of Public Health, Los Angeles, CA, USA
Maoyong
Fu
Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
Madhuri
Wadehra
Pathology and Laboratory Medicine, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, Los Angeles, CA; Center to Eliminate Cancer Health Disparities, Charles Drew University, Los Angeles, CA
David
Chia
Department of Pathology, UCLA David Geffen School of Medicine at UCLA, Los Angeles, CA
Steve
Horvath
Department of Biostatistics, UCLA School of Public Health; and Jonsson Comprehensive Cancer Center, Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
Lee
Goodglick
Jonsson Comprehensive Cancer Center, Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
TMA
cancer
biomarker
prognostic marker
immunohistochemistry
Traditional methods for analyzing large numbers of tissue samples require significant amounts of time, plentiful costly reagents, and highly skilled technicians. The development of tissue microarrays has provided an alternative method, allowing for high-throughput screening and analysis of hundreds of samples on a single slide. This has powerful implications for the identification and characterization of biomarkers involved in cancer progression and outcome. In this review, we describe methods of designing and constructing a tissue microarray, as well as techniques for quantifying and analyzing biomarker expression using a tissue microarray.
Prognostic and Predictive Role of Raf Kinase Inhibitor Protein (RKIP) Within the RAS/ MAP Signaling Pathway in Colorectal Cancer
161-169
10.1615/ForumImmunDisTher.v2.i2.70
A.
Lugli
Institute of Pathology, University of Bern, Bern, Switzerland
P.
Minoo
Department of Pathology, University of California San Diego, San Diego, CA, USA
I.
Zlobec
Institute of Pathology, University of Bern, Bern, Switzerland
colorectal cancer
prognosis
prediction
immunohistochemistry
According to the UICC (Union Internationale Contre le Cancer) the essential prognostic factors in colorectal cancer (CRC) include T stage (T), N stage (N), M stage (M), and the information on lymphatic (L) and vascular (V) invasion. Although patients with Stage III disease normally receive postoperative adjuvant therapy, the treatment of Stage II patients is still a matter of controversy. Therefore, several studies have focused in the last several years on novel independent prognostic factors that, in addition to TNM stage, may better stratify CRC patients into prognostic subgroups. Nevertheless, the implementation of biomarkers into daily practice, especially using immunohistochemistry, can be very problematic due to the lack of standardization and reproducibility. The RAS signaling pathway is one of the most important pathways involved in the pathogenesis of CRC and is of growing interest due to KRAS mutational status and its potential predictive value in patients with metastatic CRC treated with anti-EGFR therapy. Consequently, many downstream molecules of the RAS signaling pathway, such as BRAF and PIK3, have been studied. An additional and important protein is the Raf kinase inhibitor protein (RKIP). The aim of this review is to investigate on the potential prognostic and predictive role of RKIP in CRC.
Clinical Significance of RKIP and Phosphorylated RKIP Expression in Human Cancers
171-178
10.1615/ForumImmunDisTher.v2.i2.80
Lee
Goodglick
Jonsson Comprehensive Cancer Center, Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
Benjamin
Bonavida
Department of Microbiology, Immunology, &
Molecular Genetics, David Geffen School of Medicine at UCLA, Johnson Comprehensive Cancer Center, University of California at Los Angeles, Los Angeles, CA 90025-1747, USA
RKIP
phosphorylated RKIP
pRKIP
prognosis
RKIP/pRKIP expression
metastasis
therapy resistance
Recent findings have demonstrated the activity of a new gene product, RKIP, and its role in the regulation of cancer cell survival and response to apoptotic stimuli. RKIP has been implicated in certain cancers to be a suppressor of metastasis and of immune surveillance. However, in some tumors, the level of RKIP expression did not correlate with resistance or metastasis. Because most of these studies were performed with an antibody that detects both nonphosphorylated and inactive phosphorylated RKIP (pRKIP), it was possible that in some cancers, the expression of pRKIP may be implicated in the interpretation of the findings. A specific antiphospho antibody is available and detects pRKIP at serine 153 and can be used to determine the level of pRKIP in comparison to total RKIP. Studies in lung tumor tissue microarrays demonstrated that, although the total RKIP levels were not of prognostic significance, the levels of pRKIP had powerful predictive value for disease-specific survival. These findings are the first to demonstrate the involvement of pRKIP and its significance in cancer. These results also suggest that it might be fruitful and important to analyze both RKIP and pRKIP in all cancers.
Unique Pattern of Overexpression of Raf-1 Kinase Inhibitory Protein in Its Inactivated Phosphorylated Form in Human Multiple Myeloma
179-188
10.1615/ForumImmunDisTher.v2.i2.90
Stavroula
Baritaki
Center for Systems Biomedicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
Sara
Huerta-Yepez
Hospital Infantil de México Federico Gomez
Ma da Lourdas
Cabrava-Haimandez
Servicio da Patologia, Hospital Infantil de Mexico Federico Gomez, Mexico City, Mexico
Marialuisa
Sensi
Department of Experimental Oncology, Fondazione IRCCS, Istituto Nazionale dei Tumori, Milan, Italy
Silvana
Canevari
Fondazione IRCCS Istituto Nazionale dei Tumori; Unit of Molecular Therapies, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
Massimo
Libra
Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania; Research Centre for Prevention, Diagnosis and Treatment of Cancer, University of Catania, 95123 Catania, Italy
Manuel
Penichet
Division of Surgical Oncology, Department of Surgery, UCLA David Geffen School of Medicine; The Jonsson Comprehensive Cancer Center, The Molecular Biology Institute, Department of Microbiology, Immunology, and Molecular Genetics, UCLA
Haiming
Chen
Institute for Myeloma and Bone Cancer Research, West Hollywood, CA, USA
James R.
Berenson
Institute for Myeloma and Bone Cancer Research, West Hollywood, CA, USA
Benjamin
Bonavida
Department of Microbiology, Immunology, &
Molecular Genetics, David Geffen School of Medicine at UCLA, Johnson Comprehensive Cancer Center, University of California at Los Angeles, Los Angeles, CA 90025-1747, USA
NF-kB
Raf-1 kinase inhibitor protein (RKIP)
apoptosis
multiple myeloma
Multiple myeloma (MM) is the second most common hematological and incurable malignancy of plasma cells with low proliferative activity in the bone marrow. MM patients initially respond to conventional therapy, however, many develop resistance and recurrences occur. We have identified RKIP as a novel gene product that is differentially overexpressed in MM cell lines and MM tissues compared to other studied tumors and normal bone marrow. This overexpression consisted, in large part, of a phosphorylated inactive form of RKIP at Ser153 (p-Ser153 RKIP). In contrast to RKIP, p-Ser153 RKIP lacks its ability to inhibit the MAPK signaling pathway. The overexpression of p-Ser153 RKIP in MM cell lines and MM tissues was further validated in a mouse model carrying a human MM xenograft, namely, LAGλ-1B. Bioinformatic analyses from databases support the presence of increased RKIP mRNA expression in MM compared to normal plasma cells. In these databases, high RKIP levels in MM are also correlated with the nonhyperdiploid status and the presence of IgH translocations, parameters that generally display more aggressive clinical features and shorter patients’ survival irrespective of the treatment. Since RKIP expression regulates both the NF-κB and MAPK survival pathways, the overexpression of "inactive" p-Ser153 RKIP in MM might contribute positively to the overall cell survival/antiapoptotic phenotype and drug resistance of MM through the constitutive activation of survival pathways and downstream the transcription of anti-apoptotic gene products. The overexpression of RKIP and p-Ser153 RKIP in MM is the first demonstration in the literature, since in most tumor tissues the expression of RKIP is very low and the expression of p-Ser153 RKIP is much lower. The relationship between the levels of active RKIP and inactive p-Ser153 RKIP in MM may be of prognostic significance, and the regulation of RKIP activity may be a target for therapeutic intervention.
Braf Mutations Are Associated With High Levels of Phosphorylated RKIP in Melanoma Cell Lines: Potential Prognostic Significance
189-194
10.1615/ForumImmunDisTher.v2.i2.100
Sara
Huerta-Yepez
Hospital Infantil de México Federico Gomez
S.
Ekmekcioglu
The University of Texas MD Anderson Cancer Center, Houston, TX, USA
C. M.
Rivera-Pazos
Unidad de Investigacion en Enfermedades Oncologicas, Hospital Infantil de Mexico, Col. Doctores, Mexico, City, Mexico
G.
Antonio-Andres
Unidad de Investigacion en Enfermedades Oncologicas, Hospital Infantil de Mexico, Col. Doctores, Mexico, City, Mexico
Mario I.
Vega
Oncology Research Unit, Oncology Hospital Siglo XXI National Medical Center IMSS, Mexico City, Mexico; Department of Medicine, Hematology-Oncology Division, Greater Los Angeles VA Healthcare Center, David Geffen School of
Medicine, University of California, Los Angeles
G.
Baay-Guzman
Unidad de Investigacion en Enfermedades Oncologicas, Hospital Infantil de Mexico, Col. Doctores, Mexico, City, Mexico
Elizabeth A.
Grimm
University of Texas MD Anderson Cancer Center, 1515 Holcombe Avenue, Mail Unit 421, Room FC 11.2048, Houston, TX 77030
melanoma
BRAF mutation
NRAS mutation
phospho-RKIP
prognosis
BRAF proto-oncogene is a serine-threonine protein kinase that functions as an immediate down-stream effector of RAS. Activated BRAF mutations are found at high frequency in melanoma, where they occur at a frequency of 50−70%. The mutation increases protein kinase activity, resulting in constitutive BRAF/MEK/ERK signaling. Raf kinase inhibitor protein (RKIP) is a inhibitor of the MAP kinase cascade because it dissipates the Raf-1/MEK interaction, thereby preventing activation of MEK by Raf-1 and downstream signal transduction. RKIP expression is decreased in melanoma and absent in melanoma metastases. We hypothesized that BRAF mutations, through their activation of PKCs, will result in the phosphorylation and inactivation of RKIP and potentiation of ERK 1/2 activation, metastasis, and drug resistance. We have examined a large panel of melanoma cell lines with no mutations and with BRAF mutations using a tissue microarray technology. The expression of both RKIP and phospho (p) RKIP was examined and protein expression was performed by IHC and analyzed. Our results revealed that the majority (75%) of RKIP expression was in its phosphorylated form in cell lines with BRAF mutations. We suggest that in melanoma cell lines with BRAF mutations, GRK2 is inactivated through its association with pRKIP and, thus, maintaining the activating signals mediated by GPCRs.
Role of Raf Kinase Inhibitor Protein in Hepatocellular Carcinoma
195-204
10.1615/ForumImmunDisTher.v2.i2.110
Evan J.
Walker
Liver Research Center, Rhode Island Hospital and The Warren Alpert Medical School of Brown University, Providence, RI, USA
Stephen A.
Rosenberg
Liver Research Center, Rhode Island Hospital and The Warren Alpert Medical School of Brown University, Providence, RI, USA
Jack R.
Wands
Liver Research Center, Rhode Island Hospital and The Warren Alpert Medical School of Brown University, Providence, RI, USA
Miran
Kim
Liver Research Center, Rhode Island Hospital and The Warren Alpert Medical School of Brown University, Providence, RI, USA
hepatocellular carcinoma
Raf kinase inhibitor protein
post-transcriptional regulation
Hepatocellular carcinoma (HCC) accounts for 80−90% of primary liver tumors and is one of the most common and devastating malignant diseases worldwide. The MAPK signaling pathway is activated in over 90% of HCCs, and RKIP has been identified as an inhibitor of the MAPK pathway. It has been observed that downregulation of RKIP expression in HCC tumors contributes to constitutive activation of the ERK/MAPK pathway and promotes proliferation and migration of HCC cells. More important, activation of IGF-I/ERK/MAPK pathways can be blocked by restoration of RKIP levels. The protein levels of RKIP are significantly reduced in HCC, whereas mRNA levels only decreased in 41% of HCC samples studied, suggesting that the downregulation of RKIP in HCC may be influenced through multiple mechanisms both at the mRNA and protein levels. In this context, mTOR inhibitor, insulin, and proteasome inhibitors were found to modulate RKIP expression in FOCUS HCC cells. A better understating of mechanisms by which RKIP expression is downregulated in HCC may be critical to develop a possible target for therapeutic intervention of HCC.