UCLA Researchers Significantly Inhibit Growth of Ovarian Cancer Cell Lines With FDA-Approved Leukemia Drug Dasatinib (Sprycel®)

The drug dasatinib (Sprycel®), approved for use by the U.S. Food and Drug Administration in patients with specific types of leukemia, significantly inhibited the growth and invasiveness of ovarian cancer cells and also promoted their death, say UCLA researchers in the November 10th issue of the British Journal of Cancer. The drug, when paired with a chemotherapy regimen, was even more effective in fighting ovarian cancer cell lines in which signaling of the Src family kinases — associated with approximately one-third of ovarian cancers– is activated. Clinical trials that involve the testing of dasatinib against ovarian cancer and solid tumors are currently ongoing.

Researchers affiliated with the University of California, Los Angeles (UCLA), Mayo Clinic and Harvard Medical School announced that they have established a biological rationale to support the clinical study of the U.S. Food & Drug Administration (FDA)-approved leukemia drug dasatinib (U.S. brand name: Sprycel®), either alone or in combination with chemotherapy, in patients with ovarian cancer. The study appears in the November 10th edition of the British Journal of Cancer.

Background

Dasatinib is an FDA-approved drug for the treatment of chronic myeloid leukemia (CML) and Philadelphia chromosome positive acute lymphoblastic leukemia (ALL). Dasatinib is a small-molecule inhibitor that targets several tyrosine kinases, including the Src kinase family, Ephrin type-A receptor 2 ( EphA2) , and the focal adhesion kinase (FAK).

Src is the prototypic member of a family of nine non-receptor tyrosine kinases (Src, Lyn, Fyn, Lck, Hck, Fgr, Blk, Yrk, and Yes). The Src family kinase (SFK) proteins regulate four main cellular fuctions that ultimately control the behavior of transformed cancer cells:  cell proliferation, adhesion, invasion, and motility.

Eph receptors and ephrins are integral players in cancer formation and progression, and are associated with advanced ovarian cancer and poor clinical outcome.

FAK is a non-receptor tyrosine kinase involved in the regulation of cell adhesion, survival, and migration.  Preclinical studies indicate that FAK plays a signficant role in ovarian cancer cell migration and invasion.

Dasatinib Study Methodology & Findings

slamon1

One of the dasatinib study authors is Dennis J. Slamon, M.D. Ph.D. Dr. Slamon is the Director of Clinical/Translational Research & Director of the Revlon/UCLA Women's Cancer Research Program, at the UCLA Jonsson Comprehensive Cancer Center. He is also the co-discoverer of Herceptin®, a targeted therapy that revolutionized the treatment of HER-2 positive breast cancer.

The researchers carried out the study by testing the effects of dasatinib on human ovarian cancer cells in vitro, using a panel of 34 established human ovarian cancer cell lines.  The 34 cell lines selected were representative of the major epithelial ovarian cancer subtypes:

On this basis, the researchers examined the effects of dasatinib on ovarian tumor cell proliferation, invasion, apoptosis, and cell-cycle arrest.  To more fully understand the activity of dasatinib, the researchers also studied the efficacy of chemotherapeutic drugs (i.e., carboplatin and paclitaxel) in combination with dasatinib against ovarian cancer cells that were previously determined to be dasatinib-sensitive.

The overarching goals of the study were (i) to provide a rationale to test dasatinib as a single agent or in combination with chemotherapy in patients with ovarian cancer, and (ii) to identify molecular markers that may help define subsets of ovarian cancer patients most likely to benefit from treatment with dasatinib.

Significant findings reported in the dasatinib study are summarized below.

  • Concentration-dependent, anti-proliferative effects of dasatinib were seen in all ovarian cancer cell lines tested.
  • Dasatinib significantly inhibited tumor cell invasion, and induced tumor cell death, but was less effective in causing tumor cell-cycle arrest.
  • At a wide range of clinically achievable drug concentrations, additive and synergistic interactions were observed for dasatinib plus carboplatin or paclitaxel.
  • 24 out of 34 (71%) representative ovarian cancer cell lines were highly sensitive (i.e.,  ≥ 60% growth inhibition) to dasatinib.
  • 6 cells lines were moderately sensitive (i.e., 40% – 59% growth inhibition) to dasatinib.
  • 4 cell lines were resistant (i.e., < 40% growth inhibition) to dasatinib.
  • When comparing dasatinib sensitivity between cell lines based solely upon histological subtype (i.e., serous papillary, clear cell, endometrioid, mucinous, and undifferentiated ovarian cancer cell lines), no single histological subtype was more sensitive than another.
  • Ovarian cancer cell lines with high expression of Yes, Lyn, Eph2A, caveolin-1 and 2, moesin, annexin-1 and 2 and uPA (urokinase-type Plasminogen Activator), as well as those with low expression of IGFBP2 (insulin-like growth factor binding protein 2), were particularly sensitive to dasatinib.
  • Ovarian cancer cell lines with high expression of HER-2 (Human Epidermal growth factor Receptor 2), VEGF (Vascular endothelial growth factor) and STAT3 (Signal Transducer and Activator of Transcription 3) were correlated with in vitro resistance to dasatinib.

Based upon the findings above, the researchers concluded that there is a clear biological rationale to support the clinical study of dasatinib, as a single agent or in combination with chemotherapy, in patients with ovarian cancer.

Konecny

Gottfried E. Konecny, M.D., UCLA Assistant Professor of Hematology/Oncology, UCLA Jonsson Comprehensive Cancer Center Researcher & First Author of the Dasatinib Study

Ovarian cancer, which will strike 21,600 women this year and kill 15,500, causes more deaths than any other cancer of the female reproductive system. Few effective therapies for ovarian cancer exist, so it would be advantageous for patients if a new drug could be found that fights the cancer, said Gottfried E. Konecny, M.D., a UCLA assistant professor of hematology/oncology, a Jonsson Comprehensive Cancer Center researcher, and first author of the study.

“I think Sprycel® could be a potential additional drug for treating patients with Src dependent ovarian cancer,” Konecny said. “It is important to remember that this work is only on cancer cell lines, but it is significant enough that it should be used to justify clinical trials to confirm that women with this type of ovarian cancer could benefit.”

Recent gene expression studies have shown that approximately one-third of women have ovarian cancers with activated Src pathways, so the drug could potentially help 7,000 ovarian cancer patients every year. Notably, a gene expression study published in 2007 reported Src activation in approximately 50% of the ovarian cancer tumors examined.

In the dasatinib study, the UCLA team tested the drug against 34 ovarian cancer cell lines and conducted genetic analysis of those lines. Through these actions, the researchers were able to identify genes that predict response to dasatinib. If the work is confirmed in human studies, it may be possible to test patients for Src activation and select those who would respond prior to treatment, thereby personalizing their care.

“We were able to identify markers in the pre-clinical setting that would allow us to predict response to Sprycel®,” Konecny said. “These may help us in future clinical trials in selecting patients for studies of the drug.”

Dasatinib is referred to as a “dirty” kinase inhibitor, meaning it inhibits more than one cellular pathway. Konecny said it also inhibits the focal adhesion kinase (FAK) and ephrin receptor, also associated with ovarian cancer, in addition to the Src cellular pathway.

The next step, Konecny said, would be to test the drug on women with ovarian cancer in a clinical trial. The tissue of responders would then be analyzed to determine if the Src and other pathways were activated. If that is confirmed, it would further prove that dasatinib could be used to fight ovarian cancer. In studies, women would be screened before entering a trial and only those with Src dependent cancers could be enrolled to provide further evidence, Konecny said, much like the studies of the molecularly targeted breast cancer drug Herceptin® enrolled only women who had HER-2 positive disease.

“Herceptin® is different because we knew in advance that it only worked in women with HER-2 [gene] amplification,” he said. “In this case, we don’t clearly know that yet. The data reassures us that the drug works where the targets are over-expressed but we need more testing to confirm this.”

The tests combining the drug with chemotherapy are significant because chemotherapy, namely carboplatin and paclitaxel, is considered the standard first line treatment for ovarian cancer patients following surgery. Because dasatinib proved to have a synergistic effect when combined with chemotherapy, it may be possible to add this targeted therapy as a first line treatment if its efficacy is confirmed in future studies.

Dasatinib Study Significance

The dasatinib study is potentially significant to the area of ovarian cancer treatment for several reasons.

First, although this study only tested dasatinib in vitro against ovarian cancer cell lines, the drug is already FDA-approved.  Accordingly, the general safety of the drug has already been established by the FDA.

Second, 71% of the ovarian cancer lines were highly sensitive to dasatinib.

Third, dasatinib was additive to, or synergistic with, the standard of care chemotherapy drugs used in first line ovarian cancer treatment, i.e., carboplatin and paclitaxel.

Fourth, the study established molecular markers that may be predictive of dasatinib effectiveness in particular patients.  In theory, a patient’s tumor biopsy could be tested for the presence of those molecular markers to determine whether a patient will benefit from dasatinib.

Fifth, one of the dasatinib study authors is Dennis J. Slamon, M.D. Ph.D. Dr. Slamon is the director of Clinical/Translational Research, and director of the Revlon/UCLA Women’s Cancer Research Program, at the UCLA Jonsson Comprehensive Cancer Center. Dr. Slamon is also the co-discoverer of Herceptin®, a targeted therapy that revolutionized the treatment of HER-2 positive breast cancer.  Herceptin® is a targeted therapy that kills HER-2 positive breast cancer cells while leaving normal cells unaffected.  The potential use of dasatinib to treat select ovarian cancer patients who test “positive” for specific molecular markers (e.g., Src cellular pathway activation) is similar to the extremely successful drug development approach used for Herceptin®.

Open Clinical Trials Testing Dasatinib (Sprycel®) Against Ovarian Cancer & Solid Tumors

As of this writing, there are several open (i.e., recruiting) clinical trials that involve testing dasatinib against ovarian cancer and solid tumors.

For a list of open clinical trials that involve testing dasatinib against ovarian cancer, CLICK HERE.

For a list of open clinical trials that involve testing dasatinib against solid tumors, CLICK HERE.

All potential volunteers must satisfy the clinical trial entrance criteria prior to enrollment.  Depending on the drug combination being tested, one or more of the solid tumor clinical trials may not be appropriate for an ovarian cancer patient.

About the UCLA Jonsson Comprehensive Cancer Center

UCLA’s Jonsson Comprehensive Cancer Center (JCCC) has more than 240 researchers and clinicians engaged in disease research, prevention, detection, control, treatment and education. One of the nation’s largest comprehensive cancer centers, JCCC is dedicated to promoting research and translating basic science into leading-edge clinical studies. In July 2009, JCCC was named among the top 12 cancer centers nationwide by U.S. News & World Report, a ranking it has held for 10 consecutive years. For more information on JCCC, visit the website at http://www.cancer.ucla.edu.

Sources:

M.D. Anderson’s EphA2-Targeted Therapy Delivers Chemo Directly to Ovarian Cancer Cells

With a novel therapeutic delivery system, a research team led by scientists at The University of Texas M. D. Anderson Cancer Center has successfully targeted a protein that is over-expressed in ovarian cancer cells. Using the EphA2 protein as a molecular homing mechanism, chemotherapy was delivered in a highly selective manner in preclinical models of ovarian cancer, the researchers report in the July 29 issue of the Journal of the National Cancer Institute. … In the models, the therapy inhibited tumor growth in treated mice by 85 percent – 98 percent compared to control mice. … [Anil] Sood said, “We are gearing up to bring it to phase I clinical trials. A lot of the safety studies are well under way or nearing completion and we anticipate that this drug will enter clinical trials within the next few months.”

M. D. Anderson-led team finds potent antitumor activity with a monoclonal antibody-chemotherapy combination

With a novel therapeutic delivery system, a research team led by scientists at The University of Texas M. D. Anderson Cancer Center has successfully targeted a protein that is over-expressed in ovarian cancer cells. Using the EphA2 protein as a molecular homing mechanism, chemotherapy was delivered in a highly selective manner in preclinical models of ovarian cancer, the researchers report in the July 29 issue of the Journal of the National Cancer Institute.

EphA2 is attractive for such molecularly targeted therapy because it has increased expression in ovarian and other cancers, including breast, colon, prostate and non-small cell lung cancers and in aggressive melanomas, and its expression has been associated with a poor prognosis.

Anil K. Sood, M.D., professor and in the Departments of Gynecologic Oncology and Cancer Biology at the Univ. of Texas M. D. Anderson Cancer Center

Anil K. Sood, M.D., professor in the Departments of Gynecologic Oncology and Cancer Biology at the Univ. of Texas M. D. Anderson Cancer Center

“One of our goals has been to develop more specific ways to deliver chemotherapeutic drugs,” said senior author Anil K. Sood, M.D., professor and in the Departments of Gynecologic Oncology and Cancer Biology at M. D. Anderson. “Over the last several years we have shown that EphA2 is a target that is present quite frequently in ovarian and other cancers, but is either present in low levels or is virtually absent from most normal adult tissues. EphA2’s preferential presence on tumor cells makes it an attractive therapeutic target.”

The researchers used a carrier system to deliver chemotherapy directly to ovarian cancer cells. The immunoconjugate contains an anti-EphA2 monoclonal antibody linked to the chemotherapy drug monomethyl auristatin phenylalanine (MMAF) through the non-cleavable linker maleimidocaproyl. Research has shown that auristatins induce cell cycle arrest at the G – M border, disrupt microtubules and induce apoptosis (programmed cell death) in cancer cells.

The investigators evaluated the delivery system’s specificity in EphA2-positive HeyA8 and EphA2-negative SKMel28 ovarian cancer cells through antibody-binding and internalization assays. They also assessed viability and apoptosis in ovarian cancer cell lines and tumor models and examined anti-tumor activity in orthotopic mouse models with mice bearing HeyA8-luc and SKOV3ip1 ovarian tumors.

According to Sood, who is also co-director of both the Center for RNA Interference and Non-Coding RNA and the Blanton-Davis Ovarian Cancer Research Program at M. D. Anderson, the immunoconjugate was highly specific in delivering MMAF to the tumor cells that expressed EphA2 while showing minimal uptake in cells that did not express the protein. In the models, the therapy inhibited tumor growth in treated mice by 85 percent – 98 percent compared to control mice.

“Once we optimized the dosing regimen, the drug was highly effective in reducing tumor growth and in prolonging survival in preclinical animal models,” Sood said. “We actually studied bulkier masses because that is what one would see in a clinical setting where there are pre-existent tumors, and even in this setting the drug was able to reduce or shrink the tumors.”

As for future research with the EphA2-silencing therapy, Sood said, “We are gearing up to bring it to phase I clinical trials. A lot of the safety studies are well under way or nearing completion and we anticipate that this drug will enter clinical trials within the next few months.”

He added that his group is simultaneously conducting preclinical testing on other chemotherapy drugs to determine which agents might combine well with the immunoconjugate used in the current study.

“There is growing interest in molecularly targeted therapy so that we are not indiscriminately killing normal cells,” Sood noted. “The goal is to make the delivery of chemotherapy more specific. The immunoconjugate we used is in a class of drugs that is certainly quite attractive from that perspective.”

Research was funded by NCI-DHHS-NIH T32 Training Grant (T32 CA101642 to A.M.N.). This research was funded in part by support from M. D. Anderson’s ovarian cancer SPORE grant (P50 CA083639), the Marcus Foundation, the Gynecologic Cancer Foundation, the Entertainment Industry Foundation, the Blanton-Davis Ovarian Cancer Research Program, and Sood’s Betty Ann Asche Murray Distinguished Professorship.

Co-authors with Sood are Jeong-Won Lee, Hee Dong Han, Mian M. K. Shahzad, Seung Wook Kim, Lingegowda S. Mangala, Alpa M. Nick, Chunhua Lu, Rosemarie Schmandt, Hye-Sun Kim, Charles N. Landen, Robert L. Coleman, all of M. D. Anderson’s Department of Gynecologic Oncology; Robert R. Langley, of M. D. Anderson’s Department of Cancer Biology; Jeong-Won Lee, also of the Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Mian M. K. Shahzad, also of the Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas; Hye-Sun Kim, also of the Department of Pathology, Cheil General Hospital and Women’s Healthcare Center, Kwandong University College of Medicine, Seoul, Korea; and Shenlan Mao, John Gooya, Christine Fazenbaker, Dowdy Jackson, and David Tice , all of MedImmune, Inc., Gaithersburg, Maryland.

Source: EphA2-Targeted Therapy Delivers Chemo Directly to Ovarian Cancer Cells – M. D. Anderson-led team finds potent antitumor activity with a monoclonal antibody-chemotherapy combination, M.D. Anderson News Release, 29 Jul. 09 [summarizing the findings of Lee JW, Han HD, Shahzad MM et. al. EphA2 Immunoconjugate as Molecularly Targeted Chemotherapy for Ovarian Carcinoma. J Natl Cancer Inst. 2009 Jul 29. [Epub ahead of print]].

Liposomal siRNA — Genetic On/Off Switches That Target Ovarian Cancer Through the Trojan Horse Effect

Use of Liposomal siRNA to Target Ovarian Cancer Protein Known as “Interleukin-8 (IL-8)”

“A protein that stimulates blood vessel growth worsens ovarian cancer, but its production can be stifled by a tiny bit of RNA wrapped in a fatty nanoparticle, a research team led by scientists at The University of Texas M. D. Anderson Cancer Center reports in the Journal of the National Cancer Institute.

The protein IL-8 is a potential therapeutic target in ovarian cancer,’ said senior author Anil Sood, M.D., professor in the M. D. Anderson Departments of Gynecologic Oncology and Cancer Biology.

The paper demonstrates that high IL-8 expression in tumors is associated with advanced tumor stage and earlier death for ovarian cancer patients. Lab experiments and research in a mouse model show that short interfering RNA (siRNA) can cut IL-8 expression, reducing tumor size by attacking its blood supply.

‘This comprehensive analysis – with human data, animal data and lab experiments to highlight the molecular mechanisms involved – helps us develop the new targets needed for a more effective approach against ovarian cancer,’ Sood said.

Interleukin-8 is overexpressed in many types of cancer and has previously been shown to promote tumor growth, new blood vessel growth known as angiogenesis, and metastasis, the spread of cancer to other organs. ‘In the long run, this research will have applications in other cancers as well,’ Sood said.

His research focuses on ovarian cancer, for example, while senior co-author Menashe Bar-Eli, Ph.D., professor in M. D. Anderson’s Department of Cancer Biology, examines IL-8’s role in melanoma.

Impact on survival

Ovarian cancer is often detected in late stages. Initial treatment includes surgery and taxane- or platinum-based chemotherapy regimens that keep the cancer at bay for a time in most patients. Recurrence is common and often lethal.

To examine IL-8’s role in ovarian cancer, the researchers analyzed tumors from 102 patients diagnosed and treated between 1988 and 2006 at M. D. Anderson and the University of Iowa. Of those, 43 had tumors with high levels of IL-8 and 59 had low levels. The median survival of those with high IL-8 tumors was 1.62 years, compared with 3.79 years for those with low expression of the protein.

All 43 tumors with high expression of IL-8 were of high grade and 42 of 43 were advanced, either stage III or IV tumors. By comparison, 10 of 59 tumors with low IL-8 expression were early stage tumors and six were of low grade.

Shrinking tumors

Genes transcribe single strands of RNA that in turn are ‘read’ by ribosomes to produce proteins. siRNAs are short, double-stranded bits of RNA capable of halting that process. The team confirmed in a lab experiment that a specific siRNA silences IL-8 and then tested it against two lines of ovarian cancer in a mouse model.

Sood, Gabriel Lopez-Berestein, M.D., professor in M. D. Anderson’s Department of Experimental Therapeutics, and colleagues are building an arsenal of siRNAs capable of silencing genes that produce cancer-promoting proteins. They packaged siRNA that stymies IL-8 into a small ball of fat known as a liposome, a combination they developed to overcome a problem – siRNA is hard to deliver to tumors.

Tumors shrank by a median of 32 percent and 52 percent in the two cancer lines among mice that received injections of the IL-8 siRNA liposome compared to those receiving control siRNA or empty liposomes.

Mice that got both the IL-8 siRNA plus the taxane-based chemotherapy drug docetaxel [Taxotere®] had median tumor weight reduction of 90 percent and 98 percent in the two cell lines. Mice with control siRNA plus docetaxel saw reductions of 67 and 84 percent.

Finally, they tested the approach in mice with an ovarian cancer cell line known to be resistant to taxane-based drugs such as docetaxel. IL-8 siRNA alone reduced the size of these tumors by 47 percent, and when combined with docetaxel reduced tumor size by 77 percent, suggesting that the combination re-sensitizes a resistant tumor to taxanes.

The team gauged the impact of IL-8 siRNA on tumor blood supply by measuring the density of blood vessels in the tumor. The IL-8 siRNA alone reduced blood vessel density by 34 percent and 39 percent in two cancer lines.

Clinical Prospects

‘These are encouraging results. We want to move one of our siRNA agents into the clinic to test its potential for therapy,’ Sood said, ‘and then in the longer term, we’ll consider moving additional siRNA agents into the clinical arena.’

The IL-8 siRNA liposome is the third developed by Sood’s and Lopez-Berestein’s team. Two others target the oncoproteins FAK and EphA2. The EphA2 siRNA liposome is closest to Phase I clinical trial, with required toxicology studies nearly complete. A clinical trial could begin within a year.

Methods used to inject siRNA in high volumes for research purposes are impractical for human therapy. Sood and Lopez-Berestein developed the liposomal approach to ensure that the siRNA reaches the cell intact so it can silence the targeted gene. Their research has shown that the liposome penetrates deeply into cells to deliver its siRNA.

Research reported in JNCI was funded by grants from the National Cancer Institute of the National Institutes of Health, including M. D. Anderson’s Specialized Program of Research Excellence in Ovarian Cancer; the Ovarian Cancer Research Fund, Inc.; and the Zarrow Foundation.”

Quoted Source: [“Researchers Identify and Shut Down Protein that Fuels Ovarian Cancer, M. D. Anderson-led team pinpoints blood vessel promoter’s role and targets it with siRNA,” M.D Anderson News Release, dated February 26, 2008]. See also “Effect of Interleukin-8 Gene Silencing With Liposome-Encapsulated Small Interfering RNA on Ovarian Cancer Cell Growth;” Merritt,W.M., Lin,Y.G., Spannuth,W.A., Fletcher,M.S., Kamat,A.A., Han,L.Y., Landen,C.N., Jennings,M., Geest,K., Langley,R.R., Villares,G., Sanguino,A., Lutgendorf,S.K., Lopez-Berestein,G., Bar-Eli,M.M., Sood, A.K.; Journal of the National Cancer Institute 2008 100(5):359-372.

Use of Liposomal siRNA to Target Ovarian Cancer Protein Known as “Focal-Adhesion Kinase (FAK)”

Recent work reported in October 2006 by Dr. Anil Sood at M.D. Anderson involved the use of a targeted “siRNAliposome in mice to identify and correct defective ovarian cancer cells. M. D. Anderson researchers used siRNA (which acts as a genetic “on/off” switch) to target an ovarian cancer protein known as focal-adhesion kinase (FAK), which is present in all ovarian cancer cells. FAK helps ovarian cancer cells survive and spread. The siRNA was rolled into a liposome – a ball of fat so small that its dimensions are measured in nanometers (billionths of a meter). Because of their tiny size, these liposomes have no problem traveling through the blood supply into cells that make up tumors through the so-called “Trojan Horse” effect. To test how well it worked, mice that were implanted with human ovarian tumors were given injections of the therapy for three to five weeks. The mice ovarian tumors experienced a 44% to 72% reduction in weight. Adding chemotherapy to the treatment boosted tumor weight reduction to the 94% to 98% range. The next step for the FAK siRNA liposome is testing for toxicity prior to studies in human patients.

Source: [ “Novel Therapy Shrinks Ovarian Tumors in Mice, Genetic Fragments Turn Off Cancer Growth Switch,” Cancer Newsline, October 2006, M.D. Anderson Cancer Center, University of Texas.]

Use of Liposomal siRNA to Target the Ovarian Cancer Kinase Known as “EphA2”

In an earlier in vitro studies, Anil Sood, M.D. et. al. demonstrated that when EphA2-targeting siRNA was combined with paclitaxel [Taxol®], tumor growth was dramatically reduced compared with treatment with paclitaxel and a nonsilencing siRNA. These studies show the feasibility of siRNA as a clinically applicable therapeutic modality.

Source: [“Therapeutic EphA2 Gene Targeting In vivo Using Neutral Liposomal Small Interfering RNA Delivery;” Landen,C.N., Chavez-Reyes, A., Bucana, C., Schmandt, R., T. Deavers, M., Lopez-Berestein, G. and Sood, A.K., The University of Texas M.D. Anderson Cancer Center, Houston, Texas; Cancer Research 65, 6910-6918, August 1, 2005.

Comment: The ultimate use of siRNA to treat ovarian cancer in humans holds future promise. Ovarian cancer survivors should monitor the development of this liposomal siRNA form of treatment because its use in human clinical trials could occur in the near future, assuming that pre-clinical trial toxicity tests demonstrate safety. Anil Sood, M.D. has developed the liposomal siRNA for IL-8, FAK, and EphA2. It is reported that human clinical trials with respect to the EphA2 siRNA treatment will begin within 12 months.