Presented at the AACR-NCI-EORTC International Conference: “Molecular Targets and Cancer Therapeutics: Discovery, Biology, and Clinical Applications”, p. 258-9, October 25, 2007, Moscone West Conference Center, San Francisco, California.

“Models of Embryonic Gene-Induced Initiation and Reversion of Adult Neoplasms”.

John H. Frenster, MD 1, and Jeannette A. Hovsepian, MD 2,

Divisions of  1 Medical Oncology, and of  2 Diagnostic Imaging,
Stanford University School of Medicine, Stanford, California 94305.
Phone: 650/367-6483, e-mail:  frensterjh@aol.com ,  hovsepianj@aol.com , http://www.euchromatin.net/

Supported in part by a USPHS Research Career Development Award (CA-17857) from the National Cancer Institute.


NetworkEditor's Perspective: "Embryonic Gene Re-expression within Adult Normal Cells".
Abstract:
Introduction:
A simple hypothesis:
More recently:
RNA trial therapy of human AML leukemia:
Embryonic RNA Pathway Models of human neoplasms:
New hypotheses for further testing:
New RNA research on embryonic genes:
Additional: EMT, the embryonic Epithelial-Mesenchymal Transition, and Human Neoplasms.
Related topics:
Further topics:
Other links:
Further information:



Abstract:

Embryonic gene re-expression can initiate adult neoplasms within normal adult mouse fibroblasts (Okito K, Ichisaki I, and Yamanaka S, “Generation of germline-competent induced pluripotent stem cells”, Nature 448: 313-317, July19, 2007). As little as only one normal embryonic gene need be re-expressed for such an adult neoplastic initiation to occur. This constitutes a minimal gene dose. The molecular mechanism is believed to involve the disruption of a normal nuclear signal between normal adult genes within the normal adult cell.

Conversely, certain microRNAs (let-7 RNA) are deficient within the resected tumors of patients with NSCLC lung cancer (Takamizawa J, Konishi H, Yanagisawa K, Tomida S, Osada H, Endo H, Harano T, Yatabe Y, Nagino M, Nimura Y, Mitsudomi T, and Takahashi T, “Reduced Expression of the Let-7 MicroRNAs in Human Lung Cancers in Association with Shortened Postoperative Survival”, Cancer Research 64: 3753-3756 (2004). When adult human NSCLC cancer cells in cell culture are treated with let-7 RNA via plasmid, their rate of growth in cultures is reduced toward normal (ibid).

The molecular mechanism is believed to reflect the known inhibitory effect of let-7 RNA on RAS and other oncogenes during embryogenesis  (Johnson SM, Grosshans H, Shingara J, Byrom M, Jarvis R, Cheng A, Labourier E, Reinert KL, Brown D, and Slack FJ, “RAS is Regulated by the Let-7 MicroRNA Family”, Cell 120: 635-647 (2005). The transcriptome context within the cell nucleus during embryogenesis is quite different from that context within the cell nucleus of the same cells during adult life. Specific single gene expression in one phase of cell life may be inappropriate, or even dangerous, in another phase of cell life.

A simple hypothesis postulates that preventing such inappropriate embryonic gene re-expression may prevent initiation of adult neoplasms, while administration of specific embryonic ribo-regulators to adult neoplastic cells may be capable of reverting the neoplastic activity of such neoplasms.

Interestingly, it has already been shown that the administration of unfractionated total RNA from the bone marrow aspirates of normal human donors into the marrow or blood of adult patients with acute myelocytic leukemia in full relapse results in significant in-vivo reductions in the leukemic state within each patient (DeCarvalho S, “Effect of RNA from Normal Human Marrow on Leukemic Marrow In-Vivo”, Nature 197:  1077-1080 (March 16, 1963).



1. Okito K, Ichisaki I, and Yamanaka S, “Generation of germline-competent induced pluripotent stem cells”, Nature 448: 313-317 (July19, 2007).

2. Takamizawa J, Konishi H, Yanagisawa K, Tomida S, Osada H, Endo H, Harano T, Yatabe Y, Nagino M, Nimura Y, Mitsudomi T, and Takahashi T, “Reduced Expression of the Let-7 MicroRNAs in Human Lung Cancers in Association with Shortened Postoperative Survival”, Cancer Research 64: 3753-3756 (2004).

3. Johnson SM, Grosshans H, Shingara J, Byrom M, Jarvis R, Cheng A, Labourier E, Reinert KL, Brown D, and Slack FJ, “RAS is Regulated by the Let-7 MicroRNA Family”, Cell 120: 635-647 (2005).

4. DeCarvalho S, “Effect of RNA from Normal Human Marrow on Leukemic Marrow In-Vivo”, Nature 197:  1077-1080 (March 16, 1963.



Introduction:

Adult neoplasms often re-express genes normally expressed only during embryogenesis. This ectopic re-appearance of RNA transcripts from these embryonic genes within normal adult cells may play a role in oncogenesis, metastases, and response to therapy of these adult cells.

For example, in the study of human non-small cell lung cancer (NSCLC), it has been observed that activity of the embryonic gene enhancer let-7  is often deficient, and that when let-7 is added back to such cancer cells in culture, the functional phenotype of the cancer cells is normalized, (Takamizawa J, Konishi H, Yanagisawa K, Tomida S, Osada H, Endoh H, Harano T, Yatabe Y, Nagino M, Nimura Y, Mitsudomi T,  and Takahashi T, “Reduced expression of the let-7 microRNAs in human lung cancers in association with shortened postoperative survival”, Cancer Res. 64: 3753–3756, 2004).

let-7 is an active locus in promoting cell differentition and maturation in embryonic cells, and is particularly important in controlling the activity of ras genes during embryogenesis, (Johnson SM, Grosshans H, Shingara J, Byrom M, Jarvis R, Cheng A, Labourier E, Reinert KL, Brown D, and Slack FJ, “RAS is regulated by the let-7 microRNA family”, Cell 120: 635–647, 2005).

It has now been shown that let-7 RNA binds to known embryonic oncogenes, and by such binding, inactivates such oncogenes within adult cells, (Mayr C, Hemann MT, and Bartel DP, "Disrupting the Pairing Between let-7 and Hmga2 Enhances Oncogenic Transformation", Science, 315: 1576-1579, 2007).

A simple hypothesis postulates that specific embryonic cell RNA enhancers can have either positive or negative effects on their target embryonic genes within specific adult cells, progressively disrupting the adult gene signaling systems.  This allows oncogenesis to initiate from as little as one normal embryonic gene abnormally re-expressing itself within one adult normal cell.


5. Takamizawa J, Konishi H, Yanagisawa K, Tomida S, Osada H, Endoh H, Harano T, Yatabe Y, Nagino M, Nimura Y, Mitsudomi T,  and Takahashi T, “Reduced expression of the let-7 microRNAs in human lung cancers in association with shortened postoperative survival”, Cancer Research 64: 3753-3756 (2004).

6. Johnson SM, Grosshans H, Shingara J, Byrom M, Jarvis R, Cheng A, Labourier E, Reinert KL, Brown D, and Slack FJ, “RAS is regulated by the let-7 microRNA family”, Cell 120: 635-647 (2005).

7. Mayr C, Hemann MT, and Bartel DP, "Disrupting the Pairing Between let-7 and Hmga2 Enhances Oncogenic Transformation", Science, 315: 1576-1579 (2007).

8. Okita, K, Ichisaka T, and Yamanaka S, "Generation of germline-competent induced pluripotent stem cells",
Nature 448: 313-317 (July19, 2007).



More recently, it has been found that the embryonic placenta-specific gene PLAC1 is found widely expressed within many human neoplasms (breast, lung, gastric, and ovarian primary tumor samples), with little or no expression in normal human tissues except normal testis and pregnant placental trophoblast (Koslowski M, Sahin U, Mitnach-Kraus R, Seitz G, Huber C, and Tureci O, “A Placenta-Specific Gene Ectopically Activated in Many Human Cancers is Essentially Involved in Malignant Cell Processes”, Cancer Research 67: (19) pp. 9528-9534 (October 1, 2007).  RNAi-mediated silencing of PLAC1 in MCF-7 and BT-549 breast cancer cells profoundly impairs motility, migration and invasion, and induces a G1–S cell cycle block  with nearly complete abrogation of proliferation.

Interestingly, it has already been shown that the administration of unfractionated total RNA from the bone marrow aspirates of normal human donors into the marrow or blood of adult patients with acute myelocytic leukemia in full relapse results in significant in-vivo reductions in the leukemic state within each patient (DeCarvalho S, “Effect of RNA from Normal Human Marrow on Leukemic Marrow In-Vivo”, Nature 197:  1077-1080 (March 16, 1963).

9. Koslowski M, Sahin U, Mitnach-Kraus R, Seitz G, Huber C, and Tureci O, “A Placenta-Specific Gene Ectopically Activated in Many Human Cancers is Essentially Involved in Malignant Cell Processes”, Cancer Research 67: (19) pp. 9528-9534 (October 1, 2007).

10. Frenster JH, "Oncogenes as Molecular Targets within Active Chromatin", Clinical Cancer Research, vol. 5, suppl. l, p. 3855s, (November, 1999).

11. DeCarvalho S, “Effect of RNA from Normal Human Marrow on Leukemic Marrow In-Vivo”, Nature 197:  1077-1080 (March 16, 1963.

12. Meisner LF, and Frenster JH, "In-Vivo Evolution within Radiation-Induced Clones of Human Lymphocytes", J. Cell Biol. vol. 39, part 2, p. 155a (1968).

13. Herstein PR, and Frenster JH, "Mated Models of Gene Regulation in Eukaryotes", "Embryonic and Fetal Antigens in Cancer", vol. 2,  pp. 5-7, (Anderson NG, Coggin JH, eds.), National Technical Information Service, U.S. Dept. Commerce, Springfield, VA., 1972.

14. Frenster JH, and Herstein PR, "Gene De-Repression".

15. Frenster JH, and Hovsepian JA, "DNA-DNA Tetraplex Model of Paired Sense-Antisense RNA Synthesis".

16. Frenster JH, and Hovsepian JA, "DNase-I Ultrastructural Probe Sites and Kissing Chromosomes".



Embryonic RNA Pathway Models of Human Neoplasms.

1. Embryonic genes are those normally expressed only during embryonic life.

2. These embryonic RNA enhancers and activators are most often not expressed within normal adult human cells.

3. The re-expression of normal embryonic genes within an adult normal cell carries the risk of initiating a neoplasm within the adult normal cell.

4. Some adult lung neoplasms express a deficiency of let-7 microRNA, with the more severe deficiency of let-7 microRNA correlating with a decreased patient survival after resection of the neoplasm.

5. Addition of let-7 microRNA via plasmid to such lung neoplastic cells in culture results in decreased growth of these cells.

6. Total unfractionated RNA from normal bone marrow donors can produce brief clinical remissions when given to relapsed patients with acute myelocytic leukemia.



New Hypotheses for Further Testing:

1. Any embryonic gene is a potential oncogene, and is capable of initiating a neoplasm when it is re-expressed within an adult normal cell.

2. Embryonic gene ribo-regulator RNAs may reverse the action of such re-expressed embryonic genes.

3. Embryonic gene re-expression within normal adult cells is a final common RNA pathway for most, if not all, human neoplasms.

4. Ribo-regulator RNA therapy may be effective in reversing the neoplastic activity within neoplastic cells already damaged by chromosomal translocations, inversions, deletions, duplications or viral integrations.

5. Systems for the delivery of embryonic ribo-regulator RNAs can be developed for the therapy of adult neoplasms.

6. Ribo-regulator RNAs can be a focus of cancer therapy and of cancer prevention.



NetworkEditor's Perspective: "Embryonic Gene Re-expression within Adult Normal Cells".

Some genes within adult cells are normally expressed only during adult life.
Some genes within adult cells are normally expressed only during embryologic or fetal life.
Some genes within adult cells are normally expressed during both adult life and embryologic or fetal life.
Some genes within adult cells are not normally expressed, except during heat-shock or cold-shock.

Adult-only genes usually cannot express themselves during embryonic life.
Mixed embryo-adult genes are expressed during both embryonic life and adult life.
Embryo-only genes can be re-expressed ectopically within adult cells.

The re-expression of embryonic genes within adult cells may occur in the absence of embryonic controls.
The re-expression of embryonic genes in adult cells may initiate or revert neoplasms in the adult cells.
Each re-expression of embryonic genes within adult cells is a case unto itself.
Any embryonic gene-initiated neoplasms may have quite diverse transcription patterns.

a. Re-expression of embryonic genes within adult neoplasms now provide RNA and protein targets for effective therapy of human neoplasms:

(Wang J, Day R, Dong Y, Weintraub SJ, and Michel L,
"Identification of Trop-2 as an Oncogene and an Attractive Therapeutic Target in Colon Cancers",
Molec. Cancer Therap. 7: 280-285 (February 1, 2008).)

b. Re-expression of embryonic genes within adult neoplasms results in early invasive metastases:

( Sarrió D, Rodriguez-Pinilla SM, Hardisson D, Cano A, Moreno-Bueno G, and Palacios J,
"Epithelial-Mesenchymal Transition in Breast Cancer Relates to the Basal-like Phenotype",
Cancer Research 68, 989-997, February 15, 2008.)

c. Re-expression of embryonic RNA ribo-regulator let-7 microRNA suppresses human lung cancer cells:

(Kumar MS, Erkeland SJ, Pester RE, Chen CY, Ebert MS, Sharp PA, and Jacks T,
"Suppression of non-small cell lung tumor development by the let-7 microRNA family",
Proc. Natl. Acad. Sci. USA, vol. 105, no. 10 pp. 3903-3908 (March 11, 2008).)

d. Oncogenes may compete and/or cooperate during initiation of adult neoplasms:

(Podsypanina K, Politi K, Beverly LJ, and Varmus HE,
"Oncogene cooperation in tumor maintenance and tumor recurrence in mouse mammary tumors induced by Myc and mutant Kras",
Proc. Natl. Acad. Sci. U.S.A, 2008 Apr 1;105(13):5242-7. Epub 2008 Mar 20.)

e. Embryonic RNA controls self renewal and tumor activity in breast neoplasms:

(Yu F, Yao H, Zhu P, Zhang X, Pan Q, Gong C, Huang Y, Hu X, Su F, Lieberman J, and Song E.,
"let-7 regulates self renewal and tumorigenicity of breast cancer cells",
Cell. 2007 Dec 14;131(6):1109-23.)

f. Noncoding RNA genes are ultraconserved and altered within human neoplasms:

(Calin GA, Liu C-G, Ferracin M, Hyslop T, Spizzo R, Sevignani C, Fabbri M, Cimmino A, Lee EJ, Wojcik SE, Shimizu M, Tili E, Rossi S, Taccioli C, Pichiorri F, Liu X, Zupo S, Herlea V, Gramantieri L, Lanza G, Alder H, Rassenti L, Volinia S, Schmittgen TD, Kipps TJ, Negrini M, and Croce CM,
"Ultraconserved Regions Encoding ncRNAs Are Altered in Human Leukemias and Carcinomas",
Cancer Cell, Vol 12, 215-229, 11 September 2007.)

g. Embryonic RNA can distinguish between different types of neoplastic differentiation:

(Shell S, Park S-M, Radjabi AR, Schickel R, Kistner EO, Jewell DA, Feig C, Lengyel E, and Peter ME,
"Let-7 expression defines two differentiation stages of cancer",
Proc. Natl. Acad. Sci. U.S.A., vol. 104, no. 27, pp. 11400-11405  (July 3, 2007).

h. Embryonic stem-cell program is active within diverse human epithelial neoplasms:

(Wong DJ, Liu H, Ridky TW, Cassarino D, Segal E, and Chang HY,
"Module Map of Stem Cell Genes Guides Creation of Epithelial Cancer Stem Cells",
Cell Stem Cell, Vol 2, 333-344, 10 April 2008.)

i. Embryonic stem cell genes are active within adult human cervical cancer cells, but less so within normal, mildly dysplastic, or moderately dysplastic adult cervical cells, in patient biopsies:

(Ye F, Zhou C, Cheng Q, Shen J,  and Chen H,
"Stem cell abundant protein Nanog, Nucleostemin and Musashi1 highly expressed in malignant cervical epithelial cells",
BMC Cancer April 18, 2008, 8:108, doi:10.1186/1471-2407-8-108.)

j. Embryonic stem cells display many new and varied microRNAs:

(Morin RD, O’Connor MD, Griffith M, Kuchenbauer F, Delaney A, Prabhu A-L, Zhao Y, McDonald H, Zeng T, Hirst M, Eaves CJ, and Marra MA,
"Application of massively parallel sequencing to microRNA profiling and discovery in human embryonic stem cells",
Genome Res. vol. 18: no. 4, pp. 610-621 (April, 2008).

k. 3D atlas of fly embryonic gene expression:

(FowlkesCC, Luengo Hendriks CL, Keränen SVE, Weber GH, Rübel O, Huang M-Y, Chatoor S, DePace AH, Simirenko L, Henriquez C, Beaton A, Weiszmann R, Celniker S, Hamann B, Knowles DW, Biggin MD, Eisen MB,, and Malik J,
"A Quantitative Spatiotemporal Atlas of Gene Expression in the Drosophila Blastoderm",
Cell, Vol 133, 364-374, 18 April 2008).

l. Embryonic let-7 RNA regulates multiple oncofetal genes re-expressed in adult cancer cells:

(Boyerinas B, Park S-M, Shomron N, Hedegaard MM, Vinther J, Andersen JS, Feig C, Xu J,  Burge CB, and Peter ME,
"Identification of Let-7–Regulated Oncofetal Genes",
Cancer Research 68, 2587-2591, April 15, 2008.)

m. Embryonic gene re-expression found within invasive de-diifferentiated adult human neoplasms:

(Ben-Porath I, Thomson MW, Carey VJ, Ge R, Bell GW, Regev A,  and Weinberg RA,
"An embryonic stem cell–like gene expression signature in poorly differentiated aggressive human tumors".
Nature Genetics 40, 499 - 507 (2008). Published online: 28 April 2008 | doi:10.1038/ng.127)

n. Novel pathways for embryonic gene re-expression and initiation of adult colonic neoplasms:

(Haigis KM, Kendall KR, Wang Y, Cheung A, Haigis MC, Glickman JN, Niwa-Kawakita M,  Sweet-Cordero A, Sebolt-Leopold J, Shannon KM, Settleman J, Giovannini M,  and  Jacks T.
"Differential effects of oncogenic K-Ras and N-Ras on proliferation, differentiation and tumor progression in the colon".
Nature Genetics 40, 600 - 608 (2008). Published online: 30 March 2008 | doi:10.1038/ng.115)

o. MicroRNAs of the noncoding variety are involved in gene regulation of hematological neoplasms.

(Fabbri M, Garzon R, Andreeff M, Kantarjian HM, Garcia-Manero G, and Calin GA,
"MicroRNAs and noncoding RNAs in hematological malignancies: molecular, clinical and therapeutic implications",
Leukemia advance online publication 6 March 2008; doi: 10.1038/leu.2008.30)

p. Noncoding microRNAs 181a and 181b suppress the leukemic state in acute myelogenous leukemia.

(Marcucci G, Radmacher MD, Maharry K, Mrózek K, Ruppert AS, Paschka P, Vukosavljevic T, Whitman SP, Baldus CD, Langer C, Liu C-G, Carroll AJ, Powell BL, Garzon R, Croce CM, Kolitz JE, Caligiuri MA, Larson RA, and Bloomfield CD,
"MicroRNA Expression in Cytogenetically Normal Acute Myeloid Leukemia",
New England Journal of Medicine vol. 358: no. 18, pp. 1919-1928 May 1, 2008.)
 

Translational Research is now evolving into Personalized Medical Care.
John H. Frenster, M.D.



Additional: EMT, the embryonic Epithelial-Mesenchymal Transition, and Human Neoplasms.

Eastham AM, Spencer H, Soncin F, Ritson S, Merry CLR, Stern PL, and Ward CM,
"Epithelial-Mesenchymal Transition Events during Human Embryonic Stem Cell Differentiation",
Cancer Research 67, 11254-11262, December 1, 2007.



Related topics:

Links to Reprogramming and Neoplasia:

Links to RNA and Biological Causality:

Links to RNA as a Therapeutic Agent:



Further Topics in:  Euchromatin,  active DNA, and  RNA  ribo-regulators:

Links to Euchromatin Activator RNA Reviews:
Links to Euchromatin Activator RNA Research:
Links to Ultrastructural Probes of DNase I-Sensitive Sites:
Links to RNA as a Therapeutic Agent:
Links to Hodgkin Lymphoma Immuno-Pathology:
Links to Activated T-Lymphocyte Immunotherapy:
Links to Medical Systems Biology:
Links to Selective Gene Transcription:
Links to RNA-Induced Epigenetics:
Links to RNA-Induced Embryogenesis:
Links to RNA and Biological Causality:
Links to Reprogramming and Neoplasia:

A Brief History of Activator RNA:

"Ultrastructural Probes of Active DNA Sites, and the RNA Activators of DNA". (PowerPoint Presentation).



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